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Chen T, Xing X, Huang L, Tu M, Lai X, Wen S, Cai J, Lin S, Zheng Y, Lin Y, Xu L, Qiu Y, Qiu L, Xu Y, Wu P. Efficacy and safety of high-dose intramuscular vitamin D 2 injection in type 2 diabetes mellitus with distal symmetric polyneuropathy combined with vitamin D insufficiency: study protocol for a multicenter, randomized, double-blinded, and placebo-controlled trial. Front Endocrinol (Lausanne) 2023; 14:1202917. [PMID: 37484958 PMCID: PMC10361572 DOI: 10.3389/fendo.2023.1202917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023] Open
Abstract
Background Distal symmetric polyneuropathy (DSPN) is the most common chronic complication of type 2 diabetes mellitus (T2DM). DSPN may lead to more serious complications, such as diabetic foot ulcer, amputation, and reduced life expectancy. Observational studies have suggested that vitamin D deficiency may be associated with the development of DSPN in T2DM. However, interventional studies have found that low-dose vitamin D supplementation does not significantly improve neuropathy in DSPN. This study aims to evaluate the efficacy and safety of intramuscular injection of high-dose vitamin D (HDVD) in T2DM with DSPN combined with vitamin D insufficiency. Methods and analysis We will conduct a multicenter, randomized, double-blinded, and placebo-controlled trial in four large hospitals. All eligible participants will be randomly assigned to either the vitamin D2 supplement or placebo control group and injected intramuscularly monthly for 3 months. Additionally, anthropometric measurements and clinical data will be collected at baseline and 3 months. Adverse events will be collected at 1, 2, and 3 months. The primary outcome measure is the change in the mean Michigan Neuropathy Screening Instrument (MNSI) score at baseline and 3 months post-intervention. We will use the gold-standard liquid chromatography-tandem mass spectrometry method to distinguish between 25(OH)D2 and 25(OH)D3 levels. The MNSN score before the intervention will be used as a covariate to compare the changes between both groups before and after the intervention, and the analysis of covariance will be used to analyze the change in the MNSI score after HDVD supplementation. Discussion Glycemic control alone does not prevent the progression of DSPN in T2DM. Some studies have suggested that vitamin D may improve DSPN; however, the exact dose, method, and duration of vitamin D supplementation are unknown. Additionally, neuropathy repair requires HDVD supplementation to sustain adequate vitamin D levels. This once-a-month intramuscular method avoids daily medication; therefore, compliance is high. This study will be the first randomized controlled trial in China to analyze the efficacy and safety of HDVD supplementation for patients with T2DM and DSPN and will provide new ideas for pharmacological research and clinical treatment of diabetic neuropathy. Clinical trial registration https://www.chictr.org.cn/, identifier ChiCTR2200062266.
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Affiliation(s)
- Tao Chen
- Department of Endocrinology, Clinical Research Center for Metabolic Diseases of Fujian Province, the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
- Department of Endocrinology and Metabolism, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Xiaoyan Xing
- Department of Endocrinology and Metabolism, China-Japan Friendship Hospital, Beijing, China
| | - Lihua Huang
- Department of Tumor Radiotherapy, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Mei Tu
- Department of Endocrinology and Metabolism, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Xiaoli Lai
- Department of Endocrinology and Metabolism, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Shidi Wen
- Department of Endocrinology and Metabolism, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Jin Cai
- Department of Endocrinology and Metabolism, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Shenglong Lin
- Department of Severe Liver Disease, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China
| | - Youping Zheng
- Department of Ultrasound, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, China
| | - Yuehui Lin
- Department of Endocrinology and Metabolism, Longyan Traditional Chinese Medicine Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Longyan, China
| | - Lijuan Xu
- Department of Endocrinology and Metabolism, Longyan Traditional Chinese Medicine Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Longyan, China
| | - Yuwen Qiu
- Department of Endocrinology and Metabolism, Longyan Shanghang County Hospital, Longyan, China
| | - Lumin Qiu
- Department of Endocrinology and Metabolism, Longyan Shanghang County Hospital, Longyan, China
| | - Yuebo Xu
- Department of Diabetes, Longyan Boai Hospital, Longyan, China
| | - Peiwen Wu
- Department of Endocrinology, Clinical Research Center for Metabolic Diseases of Fujian Province, the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
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Kim H, Yuan C, Nguyen LH, Ng K, Giovannucci EL. Prediagnostic Vitamin D Status and Colorectal Cancer Survival by Vitamin D Binding Protein Isoforms in US Cohorts. J Clin Endocrinol Metab 2023; 108:e223-e229. [PMID: 36550068 PMCID: PMC10188303 DOI: 10.1210/clinem/dgac742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
CONTEXT Lower 25-hydroxyvitamin D (25(OH)D) levels have consistently been associated with higher mortality among participants with colorectal cancer (CRC). OBJECTIVE To investigate whether the association between 25(OH)D and CRC mortality differs according to vitamin D binding protein (also known as Gc) isoforms. METHODS We examined the association between prediagnostic 25(OH)D levels and overall and CRC-specific mortality among participants with CRC within 2 prospective US cohorts. Cox proportional hazards regression was used to estimate the hazard ratios (HRs) and 95% CIs. RESULTS 588 participants with CRC were observed until the date of death or last follow-up (2018), whichever came first. Deficient vs sufficient 25(OH)D concentrations (<30 vs ≥50 nmol/L) were associated with higher overall mortality (HR 2.06; 95% CI 1.34-3.18) but not with CRC-specific mortality (HR 1.51; 95% CI 0.75-3.07). The HRs for overall mortality comparing deficient vs sufficient concentrations were 2.43 (95% CI 1.26-4.70) for those with the Gc1-1 isoform (rs4588 CC) and 1.63 (95% CI 0.88-3.02) for those with the Gc1-2 or Gc2-2 (rs4588 CA or AA) isoform (P for interaction = .54). The HRs for CRC-specific mortality were 1.18 (95% CI 0.27-5.14) for those with the Gc1-1 isoform and 1.41 (95% CI 0.62-3.24) for those with the Gc1-2 or Gc2-2 isoform (P for interaction = .94). CONCLUSION In these 2 US cohorts, we found that lower 25(OH)D levels were associated with higher overall mortality, but this association did not differ by Gc isoforms.
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Affiliation(s)
- Hanseul Kim
- Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Chen Yuan
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA
| | - Long H Nguyen
- Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Kimmie Ng
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA
| | - Edward L Giovannucci
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
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Villamor E, Oliveros H, Marín C, López-Arana S, Agudelo-Cañas S. Increased Serum Total and Free 25-Hydroxyvitamin D with Daily Intake of Cholecalciferol-Fortified Skim Milk: A Randomized Controlled Trial in Colombian Adolescents. J Nutr 2023; 153:1189-1198. [PMID: 37061343 DOI: 10.1016/j.tjnut.2022.11.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/02/2022] [Accepted: 11/15/2022] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The efficacy of cholecalciferol (vitamin D3) food fortification in low- and middle-income countries near the Equator is unknown. OBJECTIVES We examined the effects of providing cholecalciferol-fortified skim milk to adolescents and their mothers on serum total 25(OH)D, free 25(OH)D, and vitamin D-binding protein (DBP) concentrations in a randomized controlled trial. METHODS We randomly assigned 80 Colombian families each with a child aged 12-14.5 y and their mother 1 L of skim milk daily, either fortified with 2400 IU (60 μg) cholecalciferol or unfortified, for 6 wk. We prescribed 500 mL of milk daily to adolescents; mothers consumed the remainder ad libitum. We estimated intent-to-treat effects as the between-arm difference in the change in serum total and free 25(OH)D and DBP concentrations from baseline to the end of follow-up. Secondary analyses included stratification by baseline characteristics and per-protocol comparisons. RESULTS Among adolescents, fortification effects (95% CI) on serum total 25(OH)D, free 25(OH)D, and DBP concentrations were 5.4 nmol/L (2.1, 8.8 nmol/L), 0.6 pmol/L (-0.2, 1.4 pmol/L), and -416 nmol/L (-944, 112 nmol/L), respectively. Effects on total 25(OH)D were stronger in adolescents with lower DBP concentrations, darker skin, less sunlight exposure, and higher compliance than in their respective counterparts. Fortification increased free 25(OH)D concentrations in high compliers. Among mothers, the effects (95% CI) on total 25(OH)D and DBP concentrations were 4.0 nmol/L (0.6, 7.5 nmol/L) and -128 nmol/L (-637, 381 nmol/L), respectively. There were no adverse events. CONCLUSIONS Provision of cholecalciferol-fortified skim milk increases serum total 25(OH)D concentrations in Colombian adolescents and adult women.
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Affiliation(s)
- Eduardo Villamor
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA.
| | - Henry Oliveros
- Departamento de Epidemiología, Facultad de Medicina, Universidad de La Sabana, Chía, Colombia
| | - Constanza Marín
- Departamento de Epidemiología, Facultad de Medicina, Universidad de La Sabana, Chía, Colombia
| | - Sandra López-Arana
- Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Morrissey C, Amiot MJ, Goncalves A, Raverdy C, Masson D, Tardivel C, Gayrard S, Carrère M, Landrier JF, Vinet A, Perez-Martin A. Vitamin D Supplementation on Carotid Remodeling and Stiffness in Obese Adolescents. Nutrients 2022; 14:nu14112296. [PMID: 35684098 PMCID: PMC9182680 DOI: 10.3390/nu14112296] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/19/2022] [Accepted: 05/25/2022] [Indexed: 02/01/2023] Open
Abstract
Obesity is associated with vitamin D (VD) deficiency and arterial stiffness. This randomized control trial assessed the effects of VD supplementation during a weight-loss program on carotid intima-media thickness (IMT) and carotid compliance in obese adolescents. Participants were randomly assigned to receive either a 12-week lifestyle program with VD supplementation (n = 13), a lifestyle program without VD supplementation (n = 13) or a control group composed of normal-weight adolescents (n = 18). Serum total and free 25-hydroxyvitamin D (25(OH)D), IMT and carotid compliance were measured before and after the trial. Insufficiency in 25(OH)D concentration was found in 73% of obese participants compared to 22% among controls. Obese adolescents had lower free 25(OH)D and displayed higher IMT but lower carotid compliance than controls. Free 25(OH)D and IMT were negatively correlated in adolescents displaying VD insufficiency at baseline. After three months, total and free 25(OH)D increased in both groups. The changes of IMT and carotid compliance were similar between groups. The changes in IMT were correlated with the changes in total 25(OH)D in obese adolescents with VD insufficiency at baseline (r = −0.59, p = 0.03). While the lifestyle program with VD supplementation did not affect carotid compliance, IMT reduction was improved in obese adolescents.
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Affiliation(s)
- Christopher Morrissey
- LAPEC UPR4278—Laboratoire de Pharm-Ecologie Cardiovasculaire, Avignon University, 84029 Avignon, France; (C.M.); (S.G.)
| | - Marie-Josèphe Amiot
- MOISA—Montpellier Interdisciplinary Center on Sustainable Agri-Food Systems, CIRAD—Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Institut Agro-SupAgro, University Montpellier, INRAE—National Research Institute for Agriculture, Food and the Environment, CIHEAM-IAMM—International Centre for Advanced Mediterranean Agronomic Studies-Mediterranean Agronomic Institute of Montpellier, 34090 Montpellier, France; (M.-J.A.); (M.C.)
| | | | - Cecile Raverdy
- SSR—Centre de Soins de Suite et de Réadaptation, Institut Saint Pierre, 34250 Palavas-les-Flots, France; (C.R.); (D.M.)
| | - Delphine Masson
- SSR—Centre de Soins de Suite et de Réadaptation, Institut Saint Pierre, 34250 Palavas-les-Flots, France; (C.R.); (D.M.)
| | - Catherine Tardivel
- UMR C2VN—Center for CardioVascular and Nutrition Research, Aix Marseille University, INSERM—National Institute of Health and Medical Research, INRAE—National Research Institute for Agriculture, Food and the Environment, 13385 Marseille, France; (C.T.); (J.-F.L.)
| | - Sandrine Gayrard
- LAPEC UPR4278—Laboratoire de Pharm-Ecologie Cardiovasculaire, Avignon University, 84029 Avignon, France; (C.M.); (S.G.)
| | - Myriam Carrère
- MOISA—Montpellier Interdisciplinary Center on Sustainable Agri-Food Systems, CIRAD—Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Institut Agro-SupAgro, University Montpellier, INRAE—National Research Institute for Agriculture, Food and the Environment, CIHEAM-IAMM—International Centre for Advanced Mediterranean Agronomic Studies-Mediterranean Agronomic Institute of Montpellier, 34090 Montpellier, France; (M.-J.A.); (M.C.)
| | - Jean-Francois Landrier
- UMR C2VN—Center for CardioVascular and Nutrition Research, Aix Marseille University, INSERM—National Institute of Health and Medical Research, INRAE—National Research Institute for Agriculture, Food and the Environment, 13385 Marseille, France; (C.T.); (J.-F.L.)
| | - Agnes Vinet
- LAPEC UPR4278—Laboratoire de Pharm-Ecologie Cardiovasculaire, Avignon University, 84029 Avignon, France; (C.M.); (S.G.)
- Correspondence:
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Weinstein SJ, Mondul AM, Layne TM, Yu K, Huang J, Stolzenberg-Solomon RZ, Ziegler RG, Purdue MP, Huang WY, Abnet CC, Freedman ND, Albanes D. Prediagnostic Serum Vitamin D, Vitamin D Binding Protein Isoforms, and Cancer Survival. JNCI Cancer Spectr 2022; 6:pkac019. [PMID: 35603848 PMCID: PMC8982405 DOI: 10.1093/jncics/pkac019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/01/2021] [Accepted: 01/07/2022] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Higher circulating vitamin D has been associated with improved overall cancer survival, but data for organ-specific cancers are mixed. METHODS We examined the association between prediagnostic serum 25-hydroxyvitamin D [25(OH)D], the recognized biomarker of vitamin D status, and cancer survival in 4038 men and women diagnosed with 1 of 11 malignancies during 22 years of follow-up (median = 15.6 years) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Multivariable-adjusted proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between baseline 25(OH)D concentration and subsequent cancer survival; we also stratified on the common vitamin D binding protein isoforms (Gc1f, Gc1s, and Gc2) defined by two single-nucleotide polymorphisms (rs7041 and rs4588) in the vitamin D binding protein gene GC. All P values were 2-sided. RESULTS Higher 25(OH)D concentrations were associated with greater overall cancer survival (HR for cancer mortality = 0.83, 95% CI = 0.70 to 0.98 for highest vs lowest quintile; Ptrend = .05) and lung cancer survival (HR = 0.63, 95% CI = 0.44 to 0.90; Ptrend = .03). These associations were limited to cases expressing the Gc2 isoform (HR = 0.38 for Gc2-2, 95% CI = 0.14 to 1.05 for highest vs lowest quintile; Ptrend = .02; and HR = 0.30 for Gc1-2/Gc2-2 combined, 95% CI = 0.16 to 0.56; Ptrend < .001 for overall and lung cancer, respectively). CONCLUSIONS Higher circulating 25(OH)D was associated with improved overall and lung cancer survival. As this was especially evident among cases with the genetically determined Gc2 isoform of vitamin D binding protein, such individuals may gain a cancer survival advantage by maintaining higher 25(OH)D blood concentrations.
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Affiliation(s)
- Stephanie J Weinstein
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Alison M Mondul
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Tracy M Layne
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kai Yu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jiaqi Huang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Rachael Z Stolzenberg-Solomon
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Regina G Ziegler
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Mark P Purdue
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Wen-Yi Huang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Christian C Abnet
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Neal D Freedman
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Demetrius Albanes
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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Dejaeger M, Antonio L, Bouillon R, Moors H, Wu FCW, O'Neill TW, Huhtaniemi IT, Rastrelli G, Forti G, Maggi M, Casanueva FF, Slowikowska-Hilczer J, Punab M, Gielen E, Tournoy J, Vanderschueren D. Aging Men With Insufficient Vitamin D Have a Higher Mortality Risk: No Added Value of its Free Fractions or Active Form. J Clin Endocrinol Metab 2022; 107:e1212-e1220. [PMID: 34662423 DOI: 10.1210/clinem/dgab743] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Low total 25-hydroxyvitamin D (25(OH)D) has been associated with mortality. Whether vitamin D in its free form or 1,25-dihydroxyvitamin D (1,25(OH)2D), provide any additional information is unclear. OBJECTIVE To determine what level of 25(OH)D is predictive for mortality and if free 25(OH)D or 1,25(OH) 2 D concentrations have any added value. METHODS This prospective cohort comprised 1915 community-dwelling men, aged 40 to 79 years. Intervention included determination of association of total and free 25(OH)D and 1,25(OH) 2 D concentrations with survival status. Vitamin D results were grouped into quintiles. For total 25(OH)D, specific cutoff values were also applied. Cox proportional hazard models were used adjusted for center, body mass index, smoking, alcohol, physical activity, season of blood sample, kidney function, and number of comorbidities. RESULTS A total of 469 (23.5%) men died during a mean follow-up of 12.3 ± 3.4 years. Compared to those with normal vitamin D values (> 30 µg/L), men with a total 25(OH)D of less than 20 µg/L had an increased mortality (hazard ratio [HR] 2.03 [95% CI, 1.39-2.96]; P < .001). Likewise, men in the lowest 3 free 25(OH)D quintiles (< 4.43 ng/L) had a higher mortality risk compared to the highest quintile (HR 2.09 [95% CI, 1.34-3.25]; P < .01). Mortality risks were similar across all 1,25(OH)2D and vitamin D binding protein quintiles. CONCLUSION Aging men with vitamin D deficiency have a 2-fold increased mortality risk. Determinations of either the free fractions of vitamin D or measurement of its active form offer no additional information on mortality risks.
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Affiliation(s)
- Marian Dejaeger
- Department of Public Health and Primary Care, KU Leuven, 3000 Leuven, Belgium
- Department of Geriatrics, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Leen Antonio
- Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Roger Bouillon
- Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Hannes Moors
- Department of Public Health and Primary Care, KU Leuven, 3000 Leuven, Belgium
- Department of Geriatrics, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Frederick C W Wu
- Division of Endocrinology, Medicine and Health, University of Manchester, Manchester, UK
| | - Terence W O'Neill
- Centre for Epidemiology Versus Arthritis, The University of Manchester & NIHR Manchester Biomedical Research Centre, Manchester University NHS Foundation Trust, M13 9PL Manchester, UK
| | - Ilpo T Huhtaniemi
- Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Campus, London W12 ONN, UK
| | - Giulia Rastrelli
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, 50121 Florence, Italy
| | - Gianni Forti
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, 50121 Florence, Italy
| | - Mario Maggi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, 50121 Florence, Italy
| | - Felipe F Casanueva
- Department of Medicine, Santiago de Compostela University, Complejo Hospitalario Universitario de Santiago (CHUS); CIBER de Fisiopatología Obesidad y Nutrición (CB06/03), Instituto Salud Carlos III, 15890 Santiago de Compostela, Spain
| | | | - Margus Punab
- Andrology Centre, Tartu University Hospital, 50090 Tartu, Estonia
- Institute of Clinical Medicine, University of Tartu, 50090 Tartu, Estonia
| | - Evelien Gielen
- Department of Public Health and Primary Care, KU Leuven, 3000 Leuven, Belgium
- Department of Geriatrics, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Jos Tournoy
- Department of Public Health and Primary Care, KU Leuven, 3000 Leuven, Belgium
- Department of Geriatrics, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Dirk Vanderschueren
- Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, 3000 Leuven, Belgium
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7
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Best CM, Zelnick LR, Thummel KE, Hsu S, Limonte C, Thadhani R, Sesso HD, Manson JE, Buring JE, Mora S, Lee IM, Cook NR, Friedenberg G, Luttmann-Gibson H, de Boer IH, Hoofnagle AN. Serum Vitamin D: Correlates of Baseline Concentration and Response to Supplementation in VITAL-DKD. J Clin Endocrinol Metab 2022; 107:525-537. [PMID: 34543425 PMCID: PMC8764322 DOI: 10.1210/clinem/dgab693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT The effect of daily vitamin D supplementation on the serum concentration of vitamin D (the parent compound) may offer insight into vitamin D disposition. OBJECTIVE To assess the total serum vitamin D response to vitamin D3 supplementation and whether it varies according to participant characteristics. To compare results with corresponding results for total serum 25-hydroxyvitamin D [25(OH)D], which is used clinically and measured in supplementation trials. DESIGN Exploratory study within a randomized trial. INTERVENTION 2000 International Units of vitamin D3 per day (or matching placebo). SETTING Community-based. PARTICIPANTS 161 adults (mean ± SD age 70 ± 6 years; 66% males) with type 2 diabetes. MAIN OUTCOME MEASURES Changes in total serum vitamin D and total serum 25(OH)D concentrations from baseline to year 2. RESULTS At baseline, there was a positive, nonlinear relation between total serum vitamin D and total serum 25(OH)D concentrations. Adjusted effects of supplementation were a 29.2 (95% CI: 24.3, 34.1) nmol/L increase in serum vitamin D and a 33.4 (95% CI: 27.7, 39.2) nmol/L increase in serum 25(OH)D. Among those with baseline 25(OH)D < 50 compared with ≥ 50 nmol/L, the serum vitamin D response to supplementation was attenuated (15.7 vs 31.2 nmol/L; interaction P-value = 0.02), whereas the serum 25(OH)D response was augmented (47.9 vs 30.7 nmol/L; interaction P-value = 0.05). CONCLUSIONS Vitamin D3 supplementation increases total serum vitamin D and 25(OH)D concentrations with variation according to baseline 25(OH)D, which suggests that 25-hydroxylation of vitamin D3 is more efficient when serum 25(OH)D concentration is low.
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Affiliation(s)
- Cora M Best
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Correspondence: Cora M. Best, PhD, MHS, RDN, Campus Box 357110, 1959 NE Pacific St. NW120, University of Washington, Seattle, WA, 98195-7110, USA.
| | - Leila R Zelnick
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - Kenneth E Thummel
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Simon Hsu
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - Christine Limonte
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - Ravi Thadhani
- Mass General Brigham, Harvard Medical School, Boston, MA, USA
| | - Howard D Sesso
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - JoAnn E Manson
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Julie E Buring
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Samia Mora
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - I-Min Lee
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Nancy R Cook
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Georgina Friedenberg
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Heike Luttmann-Gibson
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ian H de Boer
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
- Puget Sound VA Healthcare System, Seattle, WA, USA
| | - Andrew N Hoofnagle
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
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8
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Mimpen M, Rolf L, Poelmans G, van den Ouweland J, Hupperts R, Damoiseaux J, Smolders J. Vitamin D related genetic polymorphisms affect serological response to high-dose vitamin D supplementation in multiple sclerosis. PLoS One 2021; 16:e0261097. [PMID: 34855907 PMCID: PMC8638856 DOI: 10.1371/journal.pone.0261097] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/23/2021] [Indexed: 01/08/2023] Open
Abstract
Introduction A poor 25-hydroxyvitamin D (25(OH)D) status is a much replicated risk factor for developing multiple sclerosis (MS), and several vitamin D-associated single nucleotide polymorphisms (SNPs) have been associated with a higher risk of MS. However, studies on the benefit of vitamin D supplementation in MS show inconclusive results. Here, we explore whether vitamin D-associated SNPs and MS risk alleles confound serological response to vitamin D supplementation. Methods 34 participants from the SOLARIUM study consented to genotyping, of which 26 had vitamin D data available. The SOLARIUM study randomised relapsing-remitting MS patients to placebo or 14,000 IU vitamin D3 for 48 weeks. Participants were categorised as either ‘carriers’ or ‘non-carriers’ of the risk allele for 4 SNPs: two related to D binding protein (DBP) and associated with lower 25(OH)D levels (rs4588 and rs7041), and two related to vitamin D metabolism enzymes CYP27B1 and CYP24A1 and associated with a higher risk of MS (rs12368653; rs2248359, respectively). 25(OH)D levels were determined at baseline and after 48 weeks. Results The DBP-related SNPs showed no difference in 25(OH)D status at baseline, but carriers of the rs7041 risk allele showed lower 25(OH)D-levels compared to non-carriers after 48 weeks of supplementation (median 224.2 vs. 332.0 nmol/L, p = 0.013). For CYP related SNPs, neither showed a difference at baseline, but carriers of the rs12368653 risk allele showed higher 25(OH)D-levels compared to non-carriers after 48 weeks of supplementation (median 304.1 vs. 152.0 nmol/L, p = 0.014). Discussion Vitamin D-related SNPs affect the serological response to high-dose vitamin D supplementation. The effects on more common doses of vitamin D, as well as the clinical consequence of this altered response, need to be investigated further.
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Affiliation(s)
- Max Mimpen
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Linda Rolf
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Geert Poelmans
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Jody van den Ouweland
- Department of Clinical Chemistry, Canisius-Wilhelmina Hospital, Nijmegen, Netherlands
| | - Raymond Hupperts
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
- Department of Neurology, Zuyderland Medical Center, Sittard-Geleen, Netherlands
| | - Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, Netherlands
| | - Joost Smolders
- MS Center ErasMS, Departments of Neurology and Immunology, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Neuroimmunology, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
- * E-mail:
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9
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Zhu A, Kuznia S, Niedermaier T, Holleczek B, Schöttker B, Brenner H. Distribution and Determinants of Vitamin D-Binding Protein, Total, "Non-Bioavailable", Bioavailable, and Free 25-Hydroxyvitamin D Concentrations among Older Adults. Nutrients 2021; 13:3982. [PMID: 34836237 PMCID: PMC8624653 DOI: 10.3390/nu13113982] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND serum 25-hydroxyvitamin D (25(OH)D) ("total 25 OH(D)") is the most commonly used indicator of vitamin D status. However, 25(OH)D is mostly bound to the vitamin D binding protein (VDBP) or albumin in blood, and it has been suggested that the remaining bioavailable or free 25(OH)D may be more relevant for vitamin D associated health outcomes. We aimed to explore distributions and determinants of VDBP, total, bioavailable, complementary "non-bioavailable", and free 25(OH)D in a large cohort of older adults in Germany. METHODS total 25(OH)D, VDBP, and albumin concentrations were measured in blood samples of 5899 men and women aged 50-75 years and used to calculate bioavailable (and complementary "non-bioavailable") and free 25(OH)D concentrations. Linear regression models were used to evaluate associations of potential determinants of the various vitamin D biomarkers. RESULTS mean concentrations of VDBP, total, non-bioavailable, bioavailable, and free 25(OH)D were 323.6 µg/mL, 49.8 nmol/L, 43.4 nmol/L, 2.5 ng/mL, and 5.7 pg/mL, respectively. Seasonal variations were observed for all markers, with peak values in spring for VDBP and in summer for total, non-bioavailable, bioavailable, and free 25(OH)D. Consistent inverse associations were seen with age and body mass index for all markers, but divergent associations were seen with C-reactive protein. Strong variations by VDBP genotypes were seen for bioavailable and free 25(OH)D, and, in opposite direction for non-bioavailable 25(OH)D. CONCLUSION commonalities and differences in determinants of various markers of vitamin D status were observed, which may help to enable a better understanding of their potential role for various vitamin D related health outcomes.
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Affiliation(s)
- Anna Zhu
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Sabine Kuznia
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Tobias Niedermaier
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
| | | | - Ben Schöttker
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
- Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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10
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Heo YJ, Lee YJ, Lee K, Kim JH, Shin CH, Lee YA, Song J. Total, bioavailable and free 25-hydroxyvitamin D levels as functional indicators for bone parameters in healthy children. PLoS One 2021; 16:e0258585. [PMID: 34648586 PMCID: PMC8516284 DOI: 10.1371/journal.pone.0258585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 09/30/2021] [Indexed: 11/21/2022] Open
Abstract
Objectives Vitamin D is essential for bone health. Not only total but also free 25-hydroxyvitamin D (25OHD) may contribute to bone mass. We sought to determine which vitamin D measure best reflected clinical and bone parameters in healthy children. Methods A cross-sectional study including 146 healthy children (71 boys, 9.5 ± 1.9 years) conducted at a tertiary medical center. We used a multiplex liquid chromatography-tandem mass spectrometry-based assay to simultaneously measure vitamin D metabolites. The bioavailable and free 25OHD (25OHDBioA and 25OHDFree) levels were calculated using the genotype-specific or genotype-constant affinity coefficients of vitamin D-binding proteins (yielding spe-25OHDBioA, spe-25OHDFree and con-25OHDBioA, con-25OHDFree respectively). The 25OHDFree level was directly measured (m-25OHDFree). Bone mineral content (BMC) and bone mineral density (BMD) were assessed via dual-energy X-ray absorptiometry. Results The total 25OHD (25OHDTotal), the two forms of 25OHDBioA, the three forms of 25OHDFree, and 24,25-dihydroxyvitamin D3 levels correlated with parathyroid hormone level (all p < 0.01). Serum 25OHDTotal and m-25OHDFree levels were influenced by age, pubertal status, season, body mass index (BMI), daylight hours, and vitamin D intake (all p < 0.05). The con-25OHDBioA and con-25OHDFree levels better reflected pubertal status and daylight hours than did the spe-25OHDBioA and spe-25OHDFree levels (both p < 0.01). The association between the 25OHDTotal level and bone parameters varied according to the BMI (interaction p < 0.05). In 109 normal-weight children, the con-25OHDBioA and con-25OHDFree levels correlated with total body BMC and BMD (both p < 0.05), whereas the 25OHDTotal and 24,25-dihydroxyvitamin D3 levels were associated with total body BMC (both p < 0.05). No such association was found in overweight or obese children. Conclusions In healthy children, total, bioavailable, and free 25OHD levels comparably reflected lifestyle factors. In normal-weight children, the con-25OHDBioA and con-25OHDFree, but not m-25OHDFree levels, reflected bone mass, as did the 25OHDTotal level.
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Affiliation(s)
- You Joung Heo
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Yun Jeong Lee
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Kyunghoon Lee
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Jae Hyun Kim
- Department of Pediatrics, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Choong Ho Shin
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Young Ah Lee
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul National University College of Medicine, Seoul, Korea
- * E-mail: (YAL); (JS)
| | - Junghan Song
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
- * E-mail: (YAL); (JS)
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11
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Setayesh L, Amini A, Bagheri R, Moradi N, Yarizadeh H, Asbaghi O, Casazza K, Yekaninejad MS, Wong A, Suzuki K, Mirzaei K. Elevated Plasma Concentrations of Vitamin D-Binding Protein Are Associated with Lower High-Density Lipoprotein and Higher Fat Mass Index in Overweight and Obese Women. Nutrients 2021; 13:nu13093223. [PMID: 34579103 PMCID: PMC8472481 DOI: 10.3390/nu13093223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 09/08/2021] [Accepted: 09/15/2021] [Indexed: 12/17/2022] Open
Abstract
(1) Background: Observational studies have established that vitamin D-binding protein (DBP) and 25-hydroxyvitamin D3 (25(OH)D) concentrations are the major factors affecting the bioavailability of 25(OH)D. It has also been shown that poor 25(OH)D bioavailability elevates the risk of obesity and its related cardio-metabolic disorders. However, the relationship between 25(OH)D and DBP concentrations with cardio-metabolic risk factors in overweight and obese cohorts has not been established. Consequently, we evaluated the association between DBP and 25(OH)D concentrations with lipid profile, blood pressure (BP), and body composition in overweight and obese women. (2) Methods: In this cross-sectional study of 236 overweight and obese women, DBP and 25(OH)D concentrations were measured using an enzyme-linked immunosorbent assay. Body composition was assessed via bioelectrical impedance analysis. Lipid profile and BP were assessed by an auto-analyzer and digital BP monitor, respectively. The associations were examined by multivariate logistic regression. (3) Results: The indicated showed an inverse relationship between DBP and high-density lipoprotein (HDL) (p = 0.010) concentrations (where individuals with higher DBP had lower HDL) which, after adjusting for possible cofounders, remained significant (p = 0.006). Moreover, DBP concentration was positively associated with fat mass index (FMI) after adjustment (p = 0.022). No significant relationships were observed among 25(OH)D and target variables. (4) Conclusions: In conclusion, lower concentrations of HDL and higher values of FMI are associated with higher concentrations of DBP in overweight and obese women. These findings present novel awareness regarding the association of DBP with some metabolic and body composition variables in overweight and obese women. However, a two-way causal relationship between DBP and target variables should be considered.
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Affiliation(s)
- Leila Setayesh
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran 1417613151, Iran; (L.S.); (H.Y.)
| | - Abbas Amini
- Department of Mechanical Engineering, Australian College of Kuwait, Safat 13015, Kuwait;
| | - Reza Bagheri
- Department of Exercise Physiology, University of Isfahan, Isfahan 8174673441, Iran;
| | - Nariman Moradi
- Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj 6617713446, Iran;
| | - Habib Yarizadeh
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran 1417613151, Iran; (L.S.); (H.Y.)
| | - Omid Asbaghi
- Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran 1416753955, Iran;
| | - Krista Casazza
- Marieb College of Health and Human Services, Florida Gulf Coast University, Fort Myers, FL 33965, USA;
| | - Mir Saeed Yekaninejad
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran 1417613151, Iran;
| | - Alexei Wong
- Department of Health and Human Performance, Marymount University, Arlington, VA 22207, USA;
| | - Katsuhiko Suzuki
- Faculty of Sport Sciences, Waseda University, Tokyo 2-579-15, Japan
- Correspondence: (K.S.); (K.M.)
| | - Khadijeh Mirzaei
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran 1417613151, Iran; (L.S.); (H.Y.)
- Correspondence: (K.S.); (K.M.)
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12
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Subber Z, Al-Shamma G, Hashim H. total and free vitamin D in type 2 diabetes mellitus patients in Baghdad city. BAGHDAD JOURNAL OF BIOCHEMISTRY AND APPLIED BIOLOGICAL SCIENCES 2021. [DOI: 10.47419/bjbabs.v2i02.41] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background: The free-form of vitamin D has been used by many researchers as an index of vitamin D status in health and disease. Several methods are there to estimate free, total, and even bioavailable vitamin D.
Objective: The present work was carried out to measure free vitamin D using a special formula suggested by Bikle and Schwartz in 2019, which includes the vitamin D binding protein (VDBP). The results will be used to evaluate the vitamin D status in patients with type 2 diabetes mellitus (T2DM), and its relation to the disease progression.
Methods: Sixty-four patients with T2DM and 73 healthy subjects, all from Baghdad city, were enrolled in the current study from March to October 2020. For each participant, fasting blood glucose, hemoglobin (HbA1c), insulin resistance HOMA-IR, and body mass index (BMI) were measured in addition to the total vitamin D and VDBP. Moreover, free vitamin D was calculated by the formula of Bikle & Schwartz.
Results: There were highly significant correlations between total vitamin D and absolute values of free vitamin D or its percentage. The difference in total vitamin D was significant between patients and healthy controls with no significant change in VDBP, free and bio-available vitamin D, while free vitamin D% was higher in the patient’s group. Correlations between vitamin D and each of BMI, fasting glucose, HbA1c, and HOMA-IR were not significant; however, there was a negative correlation with BMI and fasting glucose in the healthy control subjects only. The Receiver Operating Characteristic (ROC) curve analysis of vitamin D in the diagnosis of diabetes mellitus was poor.
Conclusion: Total vitamin D can represent vitamin D status, but it cannot be used as a factor for diagnosing T2DM. However, it could be of importance to change the glycemic status.
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13
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Moon RJ, Curtis EM, Woolford SJ, Ashai S, Cooper C, Harvey NC. The importance of maternal pregnancy vitamin D for offspring bone health: learnings from the MAVIDOS trial. Ther Adv Musculoskelet Dis 2021; 13:1759720X211006979. [PMID: 33889216 PMCID: PMC8040612 DOI: 10.1177/1759720x211006979] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/12/2021] [Indexed: 12/17/2022] Open
Abstract
Optimisation of skeletal mineralisation in childhood is important to reduce childhood fracture and the long-term risk of osteoporosis and fracture in later life. One approach to achieving this is antenatal vitamin D supplementation. The Maternal Vitamin D Osteoporosis Study is a randomised placebo-controlled trial, the aim of which was to assess the effect of antenatal vitamin D supplementation (1000 IU/day cholecalciferol) on offspring bone mass at birth. The study has since extended the follow up into childhood and diversified to assess demographic, lifestyle and genetic factors that determine the biochemical response to antenatal vitamin D supplementation, and to understand the mechanisms underpinning the effects of vitamin D supplementation on offspring bone development, including epigenetics. The demonstration of positive effects of maternal pregnancy vitamin D supplementation on offspring bone development and the delineation of underlying biological mechanisms inform clinical care and future public-health policies.
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Affiliation(s)
- Rebecca J. Moon
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Tremona Road, Southampton, Hampshire SO16 6YD, UK
| | - Elizabeth M. Curtis
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, Hampshire, UK
| | - Stephen J. Woolford
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, Hampshire, UK
| | - Shanze Ashai
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, Hampshire, UK
| | - Cyrus Cooper
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, Hampshire, UK
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
- NIHR Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Nicholas C. Harvey
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, Hampshire, UK
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
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14
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Kohlmeier M, Baah E. When Mendelian randomisation fails. BMJ Nutr Prev Health 2021; 4:1-3. [PMID: 34308106 PMCID: PMC8258039 DOI: 10.1136/bmjnph-2021-000265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 12/30/2022] Open
Affiliation(s)
- Martin Kohlmeier
- Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, North Carolina, USA
| | - Emmanuel Baah
- Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, North Carolina, USA
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15
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Moosazadeh M, Nabinezhad-Male F, Afshari M, Nasehi MM, Shabani M, Kheradmand M, Aghaei I. Vitamin D status and disability among patients with multiple sclerosis: a systematic review and meta-analysis. AIMS Neurosci 2021; 8:239-253. [PMID: 33709027 PMCID: PMC7940116 DOI: 10.3934/neuroscience.2021013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 01/29/2021] [Indexed: 01/11/2023] Open
Abstract
Association between the serum vitamin D level and disability of patients with multiple sclerosis (MS) has been investigated during several researches. However, these studies reported different results. The current study aims to estimate the correlation between the concentrations of 25 (OH) vitamin D and the level of disability among MS patients. Using Mesh and non-Mesh terms related to MS, disability level and vitamin D, different data banks were searched. Required information was extracted from the selected eligible primary articles. Stata version 11 software was applied for combining the primary correlation coefficients using random effect model. The effect of MS type and patients' age was assessed using meta-regression models. Sensitivity analysis was performed to investigate the role of each primary study in the pooled estimate. Egger test was applied to find any publication bias. Of 14 eligible studies, the total correlation coefficient (95% confidence interval) between 25 (OH) vitamin D level and disability in both sexes as well as among female was estimated as of -0.29 (-0.40, -0.17) and -0.35 (-0.46, -0.24) respectively. Two articles carried out among male did not report significant results. Our meta-analysis showed a significant negative correlation between 25 (OH) vitamin D level and disability of MS patients so that the disability reduces with increasing the 25 (OH) vitamin D level.
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Affiliation(s)
- Mahmood Moosazadeh
- Gastrointestinal Cancer Research Center, Non-communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | | | - Mahdi Afshari
- Department of Community Medicine, Zabol University of Medical Sciences, Zabol, Iran
| | - Mohammad Mehdi Nasehi
- Pediatric Neurology Department, Mofid Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Motahareh Kheradmand
- Health Science Research Center, Addiction Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Iraj Aghaei
- Neuroscience Research Center, Guilan University of Medical Sciences, Rasht, Iran
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16
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El Sabeh M, Ghanem P, Al-Shaar L, Rahme M, Baddoura R, Halaby G, Singh RJ, Vanderschueren D, Bouillon R, El-Hajj Fuleihan G. Total, Bioavailable, and Free 25(OH)D Relationship with Indices of Bone Health in Elderly: A Randomized Controlled Trial. J Clin Endocrinol Metab 2021; 106:e990-e1001. [PMID: 33280041 PMCID: PMC7823248 DOI: 10.1210/clinem/dgaa780] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Indexed: 12/20/2022]
Abstract
CONTEXT Questions regarding the superiority of free and bioavailable 25-hydroxyvitamin D [25(OH)D] in predicting health outcomes remain unresolved. OBJECTIVE This study investigates the impact of vitamin D variables-total, bioavailable, or free 25(OH)D-on indices of bone and mineral metabolism, at baseline and in response to 2 vitamin D doses. DESIGN Our objectives are implemented as exploratory analyses on data collected in a 1-year, double-blind, randomized controlled trial completed in July 2014. SETTING Participants were recruited from 3 major hospitals in an ambulatory setting. PARTICIPANTS Participants were >65 years of age, overweight, and had a baseline serum 25(OH)D between 10 and 30 ng/mL. A total of 221 participants completed the study. INTERVENTION Subjects were randomized to receive calcium and oral vitamin D3 (600 IU/day or 3750 IU/day) supplementation. RESULTS Participants who received the higher vitamin D dose had levels that were 1.3- to 1.4-fold higher than those taking the lower dose, for all variables (P value < 0.001). Serum values of bioavailable and free 25(OH)D were associated with total 25(OH)D, with r values of 0.942 and 0.943, respectively (P value < 0.001). Parathyroid hormone (PTH) was negatively associated with all vitamin D variables, with correlation coefficients ranging from -0.22 to -0.25, while calcium and bone turnover markers (carboxy-terminal collagen crosslinks and osteocalcin) did not. Only total 25(OH)D had a positive relationship with % change bone mineral density (BMD) at the femoral neck at 12 months, while only free and bioavailable 25(OH) had a positive relationship with % change total body BMD at 12 months. CONCLUSION Calculated free and bioavailable 25(OH)D do not appear to be superior to total 25(OH)D in predicting indices of bone health in an elderly population.
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Affiliation(s)
- Malak El Sabeh
- Scholars in Health Research Program, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
| | - Paola Ghanem
- Scholars in Health Research Program, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
| | - Laila Al-Shaar
- Scholars in Health Research Program, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
| | - Maya Rahme
- Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, Beirut, Lebanon
| | - Rafic Baddoura
- Department of Rheumatology, Hotel Dieu de France, Beirut, Lebanon
| | - Georges Halaby
- Department of Endocrinology, Hotel Dieu de France, Beirut, Lebanon
| | - Ravinder J Singh
- Division of Clinical Biochemistry and Immunology, Mayo Clinic, Rochester, Minnesota
| | - Dirk Vanderschueren
- Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Herestraat, Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, Herestraat, Leuven, Belgium
| | - Roger Bouillon
- Department of Internal Medicine, Division of Endocrinology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Ghada El-Hajj Fuleihan
- Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, Beirut, Lebanon
- Correspondence and Reprint Requests: Ghada El-Hajj Fuleihan, MD, MPH, Professor of Medicine, Calcium Metabolism and Osteoporosis Program, American University of Beirut, Beirut, Lebanon. E-mail:
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17
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Xu F, Dai D, Sun R, Liu Z, Lin X, Li L, Xing X, Wang X, Li C, Xie Z. Long-Term Bioavailability of Single Doses of Intramuscular Vitamin D 2. Endocr Pract 2021; 26:1244-1254. [PMID: 33471654 DOI: 10.4158/ep-2020-0124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 05/24/2020] [Indexed: 11/15/2022]
Abstract
OBJECTIVE We sought to determine the long-term bioavailability of single doses of intramuscular (IM) vita-min D2 (D2) in healthy adults. METHODS Forty healthy volunteers with hypovitaminosis D received a single dose of 200,000, 400,000, or 600,000 IU intramuscular D2 or no treatment. Levels of 25-hydroxyvitamin D2 (25[OH]D2) and 25-hydroxyvitamin D3 (25[OH]D3) in serum were measured by liquid chromatography-tandem mass spectrometry. Vitamin D binding protein (DBP) and intact parathyroid hormone (iPTH), bone turnover markers (BTMs), and serum and urinary calcium were also measured. RESULTS After a single dose of D2 injection, the level of 25(OH)D2 increased slowly and reached a plateau at 8 weeks. The plateau remained stable for 12 weeks. The mean increase in 25(OH)D2 was 6.8, 9.6, or 15.6 ng/mL after injection of 200,000 IU, 400,000 IU, or 600,000 IU D2. Although endogenous 25(OH)D3 levels were reduced by IM D2, the total 25(OH)D levels increased by 5.0, 7.0, or 10.3 ng/mL in average after injection of 200,000 IU, 400,000 IU, or 600,000 IU D2. The iPTH levels were also decreased by IM D2. However, levels of serum calcium, BTMs, and DBP and urinary calcium were not altered by IM D2. CONCLUSION A single dose of 200,000 IU, 400,000 IU, or 600,000 IU IM D2 raises total 25-hydroxyvitamin D levels by 5.0, 7.0, or 10.3 ng/mL on average for at least 12 weeks and reduces iPTH and endogenous 25(OH)D3 levels without affecting levels of serum calcium, BTMs, DBP, and urinary calcium.
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Affiliation(s)
- Feng Xu
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China
| | - Dexing Dai
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China
| | - Ruoman Sun
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China
| | - Zhenming Liu
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China
| | - Xiaolin Lin
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China
| | - Lusha Li
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China
| | - Xiaoping Xing
- the Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, National Commission of Health, Chinese Academy of Medical Science, Beijing, China
| | - Xiangbing Wang
- the Division of Endocrinology, Metabolism and Nutrition, Rutgers University-Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Chunlin Li
- the Department of Geriatric Endocrinology, Chinese People's Liberation Army General Hospital, National Clinical Research Center for Geriatric Diseases, Beijing, China..
| | - Zhongjian Xie
- From the National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Hunan, China.
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Alhomsi B, Aboualchamat G, Alkadi I. Assessment of vitamin D-binding protein (DBP) gene polymorphisms and their correlation with multiple sclerosis: a case-control study in a sample of the Syrian population. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2020. [DOI: 10.1186/s43042-020-00076-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Vitamin D deficiency is a major health concern as it increases the risk of developing many serious diseases. Recently, the correlation between vitamin D deficiency and multiple sclerosis (MS) is a matter of serious debate. In this case-control study, we aimed to assess the correlation between genetic changes in the vitamin D-binding protein (DBP) gene and their consequence on MS patients. Our sample study consisted of 110 individuals; 40 patients with MS as cases and 70 healthy controls. Vitamin D levels were determined by immunofluorescence assay, and polymorphisms at rs7041 (c.1296 T > G p.Asp416Glu) and rs4588 (c.1307C > A p.Thr420Lys) of the DBP gene were genotyped using PCR/RFLP method for all cases and controls.
Results
Our results showed that genotype frequencies were consistent with Hardy-Weinberg equilibrium. A significant association was found in rs7041 (c.1296TT) homozygous wild-type, and the odds ratio was < 1 suggesting a protective role against developing MS (OR; 0.03, p = 0.0002) whereas the c.1296GG genotype was significantly correlated with an increased risk for MS by 6 folds (OR: 6.0000, p < 0.0001). No significant association was noted at rs4588 and MS occurrence. In addition, our compound genotyping results revealed that haplotypes 1S-1S are 6 times more likely to develop MS, whereas haplotypes 1F-1F had a more protective role in MS patients (OR: 0.063, p = 0.06.), respectively. The risk of vitamin D insufficiency in patients was greater by 14 folds compared to controls (OR: 14.05, p = 0.0128). Furthermore, the c.1296GG genotype was associated significantly by more than 4 times with insufficient levels of vitamin D and by 7 folds with vitamin deficiency.
Conclusions
We conclude that polymorphisms in the DBP gene could have independent effects on the risk of developing multiple sclerosis. The homozygous recessive genotype at rs7041 was associated with insufficient levels of vitamin D and with the risk of MS emergence.
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Bikle DD. The Free Hormone Hypothesis: When, Why, and How to Measure the Free Hormone Levels to Assess Vitamin D, Thyroid, Sex Hormone, and Cortisol Status. JBMR Plus 2020; 5:e10418. [PMID: 33553985 PMCID: PMC7839820 DOI: 10.1002/jbm4.10418] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/29/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
The free hormone hypothesis postulates that only the nonbound fraction (the free fraction) of hormones that otherwise circulate in blood bound to their carrier proteins is able to enter cells and exert biologic effects. In this review, I will examine four hormone groups-vitamin D metabolites (especially 25OHD), thyroid hormones (especially thyroxine [T4]), sex steroids (especially testosterone), and glucocorticoids (especially cortisol)-that are bound to various degrees to their respective binding proteins-vitamin D-binding protein (DBP), thyroid-binding globulin (TBG), sex hormone-binding globulin (SHBG), and cortisol-binding globulin (CBG)-for which a strong case can be made that measurement of the free hormone level provides a better assessment of hormonal status than the measurement of total hormonal levels under conditions in which the binding proteins are affected in levels or affinities for the hormones to which they bind. I will discuss the rationale for this argument based on the free hormone hypothesis, discuss potential exceptions to the free hormone hypothesis, and review functions of the binding proteins that may be independent of their transport role. I will then review the complications involved with measuring the free hormone levels and the efforts to calculate those levels based on estimates of binding constants and levels of both total hormone and total binding protein. In this review, the major focus will be on DBP and free 25OHD, but the parallels and differences with the other binding proteins and hormones will be highlighted. Vitamin D and its metabolites, thyroid hormones, sex steroids, and glucocorticoids are transported in blood bound to serum proteins. The tightness of binding varies depending on the hormone and the binding protein such that the percent free varies from 0.03% for T4 and 25OHD to 4% for cortisol with testosterone at 2%. Although the major function of the primary carrier proteins (DBP, TBG, SHBG, and CBG) may be to transport their respective lipophilic hormones within the aqueous media that is plasma, these proteins may have other functions independent of their transport function. For most tissues, these hormones enter the cell as the free hormone presumably by diffusion (the free hormone hypothesis), although a few tissues such as the kidney and reproductive tissues express megalin/cubilin enabling by endocytosis protein-bound hormone to enter the cell. Measuring the free levels of these protein-bound hormones is likely to provide a better measure of the true hormone status than measuring the total levels in situations where the levels and/or affinities of the binding proteins are altered. Methods to measure free hormone levels are problematic as the free levels can be quite low, the methods require separation of bound and free that could disturb the steady state, and the means of separating bound and free are prone to error. Calculation of free levels using existing data for association constants between the hormone and its binding protein are likewise prone to error because of assumptions of linear binding models and invariant association constants, both of which are invalid. © 2020 The Author. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Daniel D Bikle
- Department of Medicine University of California San Francisco USA.,Department of Medicine San Francisco VA Medical Center San Francisco CA USA
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20
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Vitamin D Supplementation Does Not Impact Resting Metabolic Rate, Body Composition and Strength in Vitamin D Sufficient Physically Active Adults. Nutrients 2020; 12:nu12103111. [PMID: 33053823 PMCID: PMC7601703 DOI: 10.3390/nu12103111] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/30/2022] Open
Abstract
Supplementation with the most efficient form of Vitamin D (VitD3) results in improvements in energy metabolism, muscle mass and strength in VitD deficient individuals. Whether similar outcomes occur in VitD sufficient individuals' remains to be elucidated. The aim of this study is to determine the effect of VitD3 supplementation on resting metabolic rate (RMR), body composition and strength in VitD sufficient physically active young adults. Participants completed pre-supplementation testing before being matched for sunlight exposure and randomly allocated in a counterbalanced manner to the VitD3 or placebo group. Following 12 weeks of 50 IU/kg body-mass VitD3 supplementation, participants repeated the pre-supplementation testing. Thirty-one adults completed the study (19 females and 12 males; mean ± standard deviation (SD); age = 26.6 ± 4.9 years; BMI = 24.2 ± 4.1 kg·m2). The VitD group increased serum total 25(OH)D by 30 nmol/L while the placebo group decreased total serum concentration by 21 nmol/L, reaching 123 (51) and 53 (42.2) nmol/L, respectively. There were no significant changes in muscle strength or power, resting metabolic rate and body composition over the 12-week period. Physically active young adults that are VitD sufficient have demonstrated that no additional physiological effects of achieving supraphysiological serum total 25(OH)D concentrations after VitD3 supplementation.
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21
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Bikle D, Christakos S. New aspects of vitamin D metabolism and action - addressing the skin as source and target. Nat Rev Endocrinol 2020; 16:234-252. [PMID: 32029884 DOI: 10.1038/s41574-019-0312-5] [Citation(s) in RCA: 170] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/12/2019] [Indexed: 12/19/2022]
Abstract
Vitamin D has a key role in stimulating calcium absorption from the gut and promoting skeletal health, as well as many other important physiological functions. Vitamin D is produced in the skin. It is subsequently metabolized to its hormonally active form, 1,25-dihydroxyvitamin D (1,25(OH)2D), by the 1-hydroxylase and catabolized by the 24-hydroxylase. In this Review, we pay special attention to the effect of mutations in these enzymes and their clinical manifestations. We then discuss the role of vitamin D binding protein in transporting vitamin D and its metabolites from their source to their targets, the free hormone hypothesis for cell entry and HSP70 for intracellular transport. This is followed by discussion of the vitamin D receptor (VDR) that mediates the cellular actions of 1,25(OH)2D. Cell-specific recruitment of co-regulatory complexes by liganded VDR leads to changes in gene expression that result in distinct physiological actions by 1,25(OH)2D, which are disrupted by mutations in the VDR. We then discuss the epidermis and hair follicle, to provide a non-skeletal example of a tissue that expresses VDR that not only makes vitamin D but also can metabolize it to its hormonally active form. This enables vitamin D to regulate epidermal differentiation and hair follicle cycling and, in so doing, to promote barrier function, wound healing and hair growth, while limiting cancer development.
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Affiliation(s)
- Daniel Bikle
- Departments of Medicine and Dermatology, University of California San Francisco, San Francisco, CA, USA.
- VA Medical Center, San Francisco, CA, USA.
| | - Sylvia Christakos
- Departments of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, the State University of New Jersey, Newark, NJ, USA
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22
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Pelczyńska M, Grzelak T, Sperling M, Kręgielska-Narożna M, Bogdański P, Czyżewska K. Evaluation of Vitamin D Fractions in Obese Hypertensive Patients. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17051660. [PMID: 32143350 PMCID: PMC7084800 DOI: 10.3390/ijerph17051660] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/16/2022]
Abstract
Vitamin D fractions can be involved in the pathogenesis of metabolic disorders, but their concentrations are rarely determined. The aim of this study was to evaluate the concentration of vitamin D fractions in obese hypertensive patients and to determine its associations with anthropometric parameters, glucose levels, and lipid profiles. A total of 85 obese hypertensive patients (OBHT) and 40 nonobese nonhypertensive subjects (NOBNHT) underwent biochemical measurements of lipid profiles, glycemia, 25-hydroxyvitamin D (25(OH)D), free vitamin D (free25(OH)D), vitamin D binding protein, albumin levels. Moreover, free25(OH)D and bioavailable25(OH)D (bio25(OH)D) concentrations were calculated. Blood pressure and anthropometric measurements were performed. Differences between groups (p < 0.001) were found for 25(OH)D (OBHT 40.25 ± 18.02 vs. NOBNHT 64.10 ± 22.29 nmol/L), free25(OH)D (9.77 (7.46; 11.49) vs. 13.80 (10.34; 16.82) pmol/L), bioavailable 25(OH)D (3.7 (2.8; 4.4) vs. 5.4 (4.2; 6.7) nmol/L), and calculated free25(OH)D (7.82 (5.54; 11.64) vs. 10.46(8.06;16.28) pmol/L, p = 0.002). The OBHT patients showed no relationship between vitamin D fractions concentration and glucose or lipids level, although it was associated with anthropometric parameters. In the NOBNHT group, vitamin D fractions correlated positively with HDL cholesterol and negatively with triglyceridemia and hip circumference. Vitamin D fractions were decreased in obese hypertensive subjects, and were associated with anthropometric parameters, but not with glucose level or lipid profiles; they thus cannot be considered as a predictive marker of metabolic disorders in this group of patients.
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Affiliation(s)
- Marta Pelczyńska
- Department of Treatment of Obesity, Metabolic Disorders and Clinical Dietetics, Poznan University of Medical Sciences, Szamarzewskiego 84 St., 60-569 Poznan, Poland
- Correspondence:
| | - Teresa Grzelak
- Department and Division of Physiology, Poznan University of Medical Sciences, Swiecickiego 6 St., 60-781 Poznan, Poland
| | - Marcelina Sperling
- Division of Biology of Civilization-Linked Diseases, Poznan University of Medical Sciences, Swiecickiego 6 St., 60-781 Poznan, Poland
| | - Matylda Kręgielska-Narożna
- Department of Treatment of Obesity, Metabolic Disorders and Clinical Dietetics, Poznan University of Medical Sciences, Szamarzewskiego 84 St., 60-569 Poznan, Poland
| | - Paweł Bogdański
- Department of Treatment of Obesity, Metabolic Disorders and Clinical Dietetics, Poznan University of Medical Sciences, Szamarzewskiego 84 St., 60-569 Poznan, Poland
| | - Krystyna Czyżewska
- Stanisław Staszic University of Applied Sciences in Pila, Podchorazych 10 St., 64-920 Pila, Poland
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23
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Vitamin D binding protein is related to cardiac autonomic function and metabolic status in prediabetes. Nutr Res 2020; 75:56-66. [PMID: 31982803 DOI: 10.1016/j.nutres.2019.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/12/2019] [Accepted: 12/19/2019] [Indexed: 11/21/2022]
Abstract
A putative causal relationship between vitamin D status and glucose metabolism and a direct effect of vitamin D on cardiac autonomic function (CAF) have been suggested. We hypothesized that vitamin D binding protein (DBP), as a transporter of vitamin D, might also influence CAF and the overall metabolic risk. The present study aims to assess the relationship between DBP and CAF and metabolic status in a high-risk population with prediabetes. A total of 174 subjects (mean age 49.1±12.9 years, mean body mass index 30.2±6.2 kg/m2) were divided into 2 groups according to glucose tolerance: 48 with normal glucose tolerance and 126 with prediabetes. Glucose tolerance was assessed during oral glucose tolerance test, applying 2006 World Health Organization criteria. Fasting and postload glucose and immunoreactive insulin were measured (homeostatic model assessment of insulin resistance and homeostatic model assessment of β-cell function were calculated). Anthropometric indexes, blood pressure, hemoglobin A1c, creatinine, lipids, high-sensitivity C-reactive protein, total 25-hydroxyvitamin D, DBP (free 25-hydroxyvitamin D was calculated), and intact parathormone were measured. Body composition was estimated by impedance analysis (InBody 720), whereas tissue advanced glycation end products were assessed by skin autofluorescence (AGE Reader, DiagnOptics, the Netherlands). CAF was evaluated by АNX-3.0 system, applying standard autonomic tests. DBP was found to be elevated in women, as well as in the presence of cardiac autonomic dysfunction and metabolic syndrome. DBP was related to parasympathetic activity in both sexes and in prediabetes; to body fat in women and in prediabetes; and to age and high-density lipoprotein cholesterol in men. Vitamin D deficiency was established in 40.8% of the studied cohort. These results support the hypothesis that DBP is associated with CAF and some metabolic parameters in prediabetes.
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24
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Smith LM, Gallagher JC. Effect of vitamin D supplementation on total and free 25 hydroxyvitamin D and parathyroid hormone. An analysis of two randomized controlled trials. J Intern Med 2019; 286:651-659. [PMID: 31215092 PMCID: PMC6851404 DOI: 10.1111/joim.12950] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND It is questionable as to whether total serum 25 hydroxyvitamin D (T25D) levels are lower in African Americans. We measured serum T25D, free 25hydroxyvitamin D (F25D) and serum parathyroid hormone (PTH) in African American and Caucasian women and studied the effect of vitamin D dosing to determine if differences by race or age occur. METHODS Healthy young and older Caucasian and African American women who were vitamin D insufficient were randomized in two clinical trials to escalating daily doses of vitamin D from 400 to 4800 IU and placebo for 12 months. RESULTS Baseline F25D and T25D were significantly lower in young but not older African American compared to Caucasian women. At baseline, the rate of change, or slope, in F25D with T25D was significantly greater in younger women than in older women, but difference in the rate of change in F25D with T25D is similar in African American and Caucasian women. After vitamin D supplementation, there was an increase in F25D, and the dose response was not significantly different by age or race. The ratio of F25D/T25D decreased in all groups once T25D exceeded ~60 nmol L-1 . There was a progressive decrease in serum PTH with increasing vitamin D doses and the per cent change was similar for F25D and T25D. CONCLUSION Serum F25D and T25D are lower in younger African American women, and since dietary vitamin D is similar in the groups, it is likely that the cause of low serum 25OHD in African American women is due to reduced UV exposure and reduced skin production of vitamin D.
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Affiliation(s)
- L M Smith
- Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE, USA
| | - J C Gallagher
- Bone Metabolism, Department Endocrinology, Creighton University School of Medicine, Omaha, NE, USA
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25
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Enlund-Cerullo M, Koljonen L, Holmlund-Suila E, Hauta-Alus H, Rosendahl J, Valkama S, Helve O, Hytinantti T, Viljakainen H, Andersson S, Mäkitie O, Pekkinen M. Genetic Variation of the Vitamin D Binding Protein Affects Vitamin D Status and Response to Supplementation in Infants. J Clin Endocrinol Metab 2019; 104:5483-5498. [PMID: 31365099 DOI: 10.1210/jc.2019-00630] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/25/2019] [Indexed: 02/04/2023]
Abstract
CONTEXT Single nucleotide polymorphisms (SNPs) of the vitamin D binding protein encoding the GC (group component) gene affect 25-hydroxyvitamin D (25OHD) concentrations, but their influence on vitamin D status and response to vitamin D supplementation in infants is unknown. OBJECTIVE To study GC genotype-related differences in 25OHD concentrations and the response to supplementation during a vitamin D intervention study in infants. DESIGN In this randomized controlled trial, healthy term infants received vitamin D3 (10 or 30 μg/d) from 2 weeks to 24 months of age. GC SNPs rs2282679, rs4588, rs7041, and rs1155563 were genotyped. rs4588/7041 diplotype and haplotypes of rs2282679, rs4588, and rs7041 (Haplo3SNP) and of all four SNPs (Haplo4SNP) were determined. MAIN OUTCOME MEASURES 25OHD measured in cord blood at birth and at 12 and 24 months during intervention. RESULTS A total of 913 infants were included. Minor allele homozygosity of all studied GC SNPs, their combined haplotypes, and rs4588/rs7041 diplotype 2/2 were associated with lower 25OHD concentrations at all time points in one or both intervention groups [analysis of covariance (ANCOVA) P < 0.043], with the exception of rs7041, which did not affect 25OHD at birth. In the high-dose supplementation group receiving 30 μg/d vitamin D3, but not in those receiving 10 µg/d, genotype of rs2282679, rs4588, and rs7041; diplotype; and Haplo3SNP significantly affected intervention response (repeated measurement ANCOVA Pinteraction < 0.019). Minor allele homozygotes had lower 25OHD concentrations and smaller increases in 25OHD throughout the intervention. CONCLUSIONS In infants, vitamin D binding protein genotype affects 25OHD concentration and efficiency of high-dose vitamin D3 supplementation.
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Affiliation(s)
- Maria Enlund-Cerullo
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Laura Koljonen
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Elisa Holmlund-Suila
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Helena Hauta-Alus
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jenni Rosendahl
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Saara Valkama
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Otto Helve
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Timo Hytinantti
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Heli Viljakainen
- Folkhälsan Research Center, Helsinki, Finland
- The Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Sture Andersson
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Outi Mäkitie
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Center for Molecular Medicine, Karolinska Institutet, and Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Minna Pekkinen
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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26
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Choi YH, Kwak JH. Letter by Choi and Kwak Regarding Article, "Serum Bioavailable and Free 25-Hydroxyvitamin D Levels, but Not Its Total Level, Are Associated With the Risk of Mortality in Patients With Coronary Artery Disease". Circ Res 2019; 125:e71-e72. [PMID: 31647768 DOI: 10.1161/circresaha.119.315631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Yoon-Hyeong Choi
- From the Department of Preventive Medicine, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Jung Hyun Kwak
- From the Department of Preventive Medicine, Gachon University College of Medicine, Incheon, Republic of Korea
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Tsuprykov O, Buse C, Skoblo R, Hocher B. Comparison of free and total 25-hydroxyvitamin D in normal human pregnancy. J Steroid Biochem Mol Biol 2019; 190:29-36. [PMID: 30904637 DOI: 10.1016/j.jsbmb.2019.03.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/05/2019] [Accepted: 03/11/2019] [Indexed: 12/25/2022]
Abstract
Vitamin D status correct monitoring during pregnancy is critically important for both maternal and fetal health. 25-Hydroxyvitamin D (25(OH)D) - a prohormone of a biologically active 1,25-dihydroxyvitamin D (1,25(OH)2D), despite the lack of biological activity, during the past decades has been routinely used as a main biomarker characterizing vitamin D status. About 85% of 25(OH)D in the bloodstream is bound to its specific carrier - vitamin D-binding protein (DBP), the remaining 15% are loosely bound to albumin, and only less than 0.1% are free in the circulation ("free 25(OH)D"). Total 25(OH)D is the sum of DBP-bound, albumin-bound and free 25(OH)D. According to a "free hormone hypothesis", only free 25(OH)D is able to induce a biological effect. Normal pregnancy is characterized by elevated serum DBP levels, and due to this fact the diagnostic strength of serum total 25(OH)D has been questioned. Free 25(OH)D might be a better characteristic of vitamin D status in this settings. We aimed to compare the diagnostic strength of a routine total 25(OH)D with directly measured free 25(OH)D in normal pregnancy by comparing the association strength between free and total 25(OH)D with biomarkers of bone health (PTH, calcium, bone-specific alkaline phosphatase (BSAP)), lipid metabolism (adiponectin, LDL, HDL), kidney function (urea), endocrine parameters (T4, T3, TSH), and group B water-soluble vitamins. The study was conducted in 368 healthy white pregnant women - residents of north-east Germany. Free 25(OH)D showed an overall better associations with gestational age, markers of bone metabolism (calcium (rho = 0.141, p = 0.007 with free 25(OH)D; rho = 0.060, p = 0.251 with total 25(OH)D) and BSAP (rho = -0.203, p < 0.001 with free 25(OH)D; rho = -0.108, p = 0.038 with total 25(OH)D), lipid metabolism parameters (adiponectin (rho = 0.142, p = 0.008 with free 25(OH)D; rho = 0.054, p = 0.307 with total 25(OH)D), LDL cholesterol (rho = -0.191, p < 0.001 with free 25(OH)D; rho = 0.033, p = 0.539 with total 25(OH)D)) and a kidney function marker (urea (rho = 0.114, p = 0.032 with free 25(OH)D; rho = 0.008, p = 0.887 with total 25(OH)D)) than total 25(OH)D. In conclusion, the current study revealed that free 25(OH)D is a more precise determinant of the vitamin D status during normal human pregnancy than total 25(OH)D. In the settings of normal pregnancy, free 25(OH)D revealed better associations with markers of bone metabolism (calcium, BSAP), lipid metabolism (adiponectin, LDL cholesterol, LDL/HDL ratio) and kidney function (urea) than total 25(OH)D.
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Affiliation(s)
- Oleg Tsuprykov
- Institute for Laboratory Medicine, IFLB, Berlin, Germany
| | | | - Roman Skoblo
- Institute for Laboratory Medicine, IFLB, Berlin, Germany
| | - Berthold Hocher
- LADR GmbH, MVZ Neuruppin, Neuruppin, Germany; Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany; Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China; Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, Hunan, China.
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Pooyan S, Rahimi MH, Mollahosseini M, Khorrami-Nezhad L, Maghbooli Z, Mirzaei K. The Association between Vitamin D Deficiency and variants of Vitamin D Binding protein gene among Healthy Iranian Adults. INT J VITAM NUTR RES 2019; 90:249-256. [PMID: 30987555 DOI: 10.1024/0300-9831/a000580] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background: The high prevalence of vitamin D deficiency may be due to both genetic and environment factors. The aim of this study was to demonstrate that vitamin D deficiency may be due to variants of vitamin D binding protein (DBP) among otherwise healthy Iranian adults. Methods: This cross-sectional study was conducted on 265 healthy adults in Tehran. Anthropometric and biochemical parameters were assessed. Dietary vitamin D intake was assessed with a Food Frequency Questionnaire (FFQ), and participant DBP genotypes were determined by polymerase chain reactions - restriction fragment length polymorphism. Results: Significant associations were found between vitamin D status and low-density lipoprotein cholesterol (P < 0.001), total cholesterol (P < 0.001), and fasting blood sugar (P < 0.001), after adjustment for confounder factors. This study demonstrated that "rs7041" gene was associated with vitamin D deficiency (OR = 0.63, β ± SE = -0.46 ± 0.14, P < 0.0001). After considering the "GG" genotype of the "rs7041" polymorphism as a reference, the prevalence of vitamin D deficiency was found to be higher in the individuals with "TT" genotype from the "rs7041" polymorphism. Conclusion: It was found that the prevalence of vitamin D deficiency was higher in individuals with T allele carriers in the "rs7041" polymorphism.
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Affiliation(s)
- Sara Pooyan
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Mohammad Hossein Rahimi
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Mehdi Mollahosseini
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Leila Khorrami-Nezhad
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Zhila Maghbooli
- Multiple Sclerosis Research Center, Neuroscience Institute of Tehran University of Medical Sciences, Tehran, Iran
| | - Khadijeh Mirzaei
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
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Marquina C, Mousa A, Scragg R, de Courten B. Vitamin D and cardiometabolic disorders: a review of current evidence, genetic determinants and pathomechanisms. Obes Rev 2019; 20:262-277. [PMID: 30450683 DOI: 10.1111/obr.12793] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/13/2018] [Accepted: 09/20/2018] [Indexed: 12/14/2022]
Abstract
Vitamin D deficiency has been implicated in the pathophysiology of cardiometabolic disorders including obesity, type 2 diabetes mellitus, cardiovascular diseases and polycystic ovary syndrome. Despite a large number of experimental and observational studies supporting a role for vitamin D in these pathologies, randomized controlled trials have reported little to no effect of vitamin D supplementation in the prevention or treatment of these disorders, although some results remain ambiguous. Polymorphisms in genes related to vitamin D metabolism, particularly in the vitamin D receptor and binding protein and the metabolizing enzyme 1-α-hydroxylase, have emerged as potential contributors to these divergent results. It is now becoming increasingly recognized that the effects and potential benefits of vitamin D supplementation may vary by several factors including vitamin D deficiency status, ethnicity and/or the presence of genetic variants, which affect individual responses to supplementation. However, these factors have seldom been explored in the available literature. Future trials should consider inter-individual differences and, in particular, should aim to clarify whether certain subgroups of individuals may benefit from vitamin D supplementation in the context of cardiometabolic health.
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Affiliation(s)
- C Marquina
- Monash Centre for Health Research and Implementation (MCHRI), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - A Mousa
- Monash Centre for Health Research and Implementation (MCHRI), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - R Scragg
- School of Population Health, The University of Auckland, Auckland, New Zealand
| | - B de Courten
- Monash Centre for Health Research and Implementation (MCHRI), School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
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Chun RF, Shieh A, Gottlieb C, Yacoubian V, Wang J, Hewison M, Adams JS. Vitamin D Binding Protein and the Biological Activity of Vitamin D. Front Endocrinol (Lausanne) 2019; 10:718. [PMID: 31708871 PMCID: PMC6821678 DOI: 10.3389/fendo.2019.00718] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022] Open
Abstract
Vitamin D has a long-established role in bone health. In the last two decades, there has been a dramatic resurgence in research interest in vitamin D due to studies that have shown its possible benefits for non-skeletal health. Underpinning the renewed interest in vitamin D was the identification of the vital role of intracrine or localized, tissue-specific, conversion of inactive pro-hormone 25-hydroxyvitamin D [25(OH)D] to active 1,25-dihydroxyvitamin D [1,25(OH)2D]. This intracrine mechanism is the likely driving force behind vitamin D action resulting in positive effects on human health. To fully capture the effect of this localized, tissue-specific conversion to 1,25(OH)2D, adequate 25(OH)D would be required. As such, low serum concentrations of 25(OH)D would compromise intracrine generation of 1,25(OH)2D within target tissues. Consistent with this is the observation that all adverse human health consequences of vitamin D deficiency are associated with a low serum 25(OH)D level and not with low 1,25(OH)2D concentrations. Thus, clinical investigators have sought to define what concentration of serum 25(OH)D constitutes adequate vitamin D status. However, since 25(OH)D is transported in serum bound primarily to vitamin D binding protein (DBP) and secondarily to albumin, is the total 25(OH)D (bound plus free) or the unbound free 25(OH)D the crucial determinant of the non-classical actions of vitamin D? While DBP-bound-25(OH)D is important for renal handling of 25(OH)D and endocrine synthesis of 1,25(OH)2D, how does DBP impact extra-renal synthesis of 1,25(OH)2D and subsequent 1,25(OH)2D actions? Are their pathophysiological contexts where total 25(OH)D and free 25(OH)D would diverge in value as a marker of vitamin D status? This review aims to introduce and discuss the concept of free 25(OH)D, the molecular biology and biochemistry of vitamin D and DBP that provides the context for free 25(OH)D, and surveys in vitro, animal, and human studies taking free 25(OH)D into consideration.
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Affiliation(s)
- Rene F. Chun
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
- *Correspondence: Rene F. Chun
| | - Albert Shieh
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Carter Gottlieb
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Vahe Yacoubian
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Jeffrey Wang
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Martin Hewison
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
| | - John S. Adams
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
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Gopal-Kothandapani JS, Evans LF, Walsh JS, Gossiel F, Rigby AS, Eastell R, Bishop NJ. Effect of vitamin D supplementation on free and total vitamin D: A comparison of Asians and Caucasians. Clin Endocrinol (Oxf) 2019; 90:222-231. [PMID: 30067874 DOI: 10.1111/cen.13825] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 07/27/2018] [Accepted: 07/29/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVES It is well established that UK Asians typically have lower vitamin D levels than Caucasians. It is also known that vitamin D binding protein (DBP) is lower in some races than Caucasians. To investigate how ethnicity, skin colour and genetic variation affect the response to vitamin D (15000 IU) administered to young Asian and Caucasian men. DESIGN Prospective, single-centre clinical trial. PARTICIPANTS Sixty young men (18-25 year) of Asian (n = 30) and Caucasian (n = 30) origin. MEASUREMENTS We measured serum calcium, phosphate, magnesium, alkaline phosphatase, albumin, parathyroid hormone; total 25 hydroxyvitamin D (25OHD); calculated and directly measured free 25OHD; DBP at baseline and 4 weeks; DBP genotype, skin colour (Fitzpatrick scale), dietary vitamin D and calcium intake at baseline; and urine calcium:creatinine ratio at baseline, 1 and 4 weeks. RESULTS At baseline, Asians had lower serum total 25OHD (26.4 [13.7] vs 34.1 [12.3] nmol/L P = 0.0272) and DBP (6.7 [3.4] vs 9.6 [4.4] nmol/L; P = 0.0065) but similar free 25OHD (16.7 [10.4] vs 17.8 [7.5] pmol/L P = 0.6530). After dosing, total 25OHD rose similarly in each group (≈56 nmol/L), but measured free 25OHD rose more in Asians (18.1 [9.4] vs 12.2 [13.3] pmol/L P = 0.0464). Lower DBP at baseline, possibly reflecting genotype differences, was associated with a greater change in measured free 25OHD in Caucasians, but not in Asians. CONCLUSIONS Asian compared with Caucasian males had a larger increment in measured free 25OHD following 150 000 units vitamin D3, possibly reflecting differences in DBP affinity for 25OHD. Ethnicity should be considered when devising guidelines for the treatment of vitamin D deficiency.
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Affiliation(s)
| | - Lucy Faith Evans
- Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
| | - Jennifer S Walsh
- Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
| | - Fatma Gossiel
- Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
| | - Alan S Rigby
- Faculty of Health, Hull York Medical School, University of Hull, Hull, UK
| | - Richard Eastell
- Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
| | - Nick J Bishop
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
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Rahimi MH, Mollahosseini M, Mirzababaei A, Yekaninejad MS, Maghbooli Z, Mirzaei K. Interactions between vitamin D binding protein variants and major dietary patterns on the odds of metabolic syndrome and its components in apparently healthy adults. Diabetol Metab Syndr 2019; 11:28. [PMID: 31007727 PMCID: PMC6454781 DOI: 10.1186/s13098-019-0422-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/14/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Recent studies have shown that the risks of chronic diseases resulting from high-risk alleles, such as cardiovascular diseases and metabolic syndrome (MetS), can be affected by various dietary patterns. Among the genes affected by environmental factors are those associated with vitamin D binding protein (DBP). METHODS This cross-sectional study was conducted on a random sample of 265 apparently healthy adults aged 18-50. MetS was defined according to the adult treatment panel III criteria. Major dietary patterns were determined using factor analysis on 24 food groups, using a valid and reliable 147-item food frequency questionnaire (FFQ). DBP genotypes were determined by polymerase chain reactions-restriction fragment length polymorphism (PCR-RFLP). RESULTS After adjustment for confounder factors, results demonstrated strong interactions between, on the one hand, a high intake of healthy pattern and DBP haplotype (rs7041/rs4588 major alleles) and on the other, low MetS odds (OR = 0.64, 95% CI 0.47-0.87, P ≤ 0.001), serum triglyceride levels (OR = 0.72, 95% CI 0.56-0.93, P = 0.01) and fasting blood glucose (OR = 0.36, 95% CI 0.14-0.96, P = 0.04). Also, individuals with a higher adherence to traditional dietary patterns demonstrated reduced odds of high waist circumference among the major allele (low-risk allele) carriers of rs7041/rs4588 (OR = 0.69, 95% CI 0.55-0.88, P = 0. 003). Interactions were also seen between high traditional pattern intake and DBP haplotype elevated blood pressure odds (OR = 1.31, 95% CI 1.02-1.68, P = 0.02). CONCLUSIONS The present evidence indicates that interactions between healthy dietary patterns with DBP haplotypes (Gc 1F, Gc 1S and Gc 2) and traditional dietary patterns with DBP haplotypes may be effective in reducing the odds of MetS and some of its components through consuming healthy food groups and inherited low risk alleles.
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Affiliation(s)
- Mohammad Hossein Rahimi
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), P.O. Box: 14155-6117, Tehran, Iran
- Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mollahosseini
- Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Atieh Mirzababaei
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), P.O. Box: 14155-6117, Tehran, Iran
| | - Mir Saeed Yekaninejad
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Zhila Maghbooli
- Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Khadijeh Mirzaei
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), P.O. Box: 14155-6117, Tehran, Iran
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Bikle DD, Schwartz J. Vitamin D Binding Protein, Total and Free Vitamin D Levels in Different Physiological and Pathophysiological Conditions. Front Endocrinol (Lausanne) 2019; 10:317. [PMID: 31191450 PMCID: PMC6546814 DOI: 10.3389/fendo.2019.00317] [Citation(s) in RCA: 227] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/01/2019] [Indexed: 12/19/2022] Open
Abstract
This review focuses on the biologic importance of the vitamin D binding protein (DBP) with emphasis on its regulation of total and free vitamin D metabolite levels in various clinical conditions. Nearly all DBP is produced in the liver, where its regulation is influenced by estrogen, glucocorticoids and inflammatory cytokines but not by vitamin D itself. DBP is the most polymorphic protein known, and different DBP alleles can have substantial impact on its biologic functions. The three most common alleles-Gc1f, Gc1s, Gc2-differ in their affinity with the vitamin D metabolites and have been variably associated with a number of clinical conditions. Although DBP has a number of biologic functions independent of vitamin D, its major biologic function is that of regulating circulating free and total levels of vitamin D metabolites. 25 hydroxyvitamin D (25(OH)D) is the best studied form of vitamin D as it provides the best measure of vitamin D status. In a normal non-pregnant individual, approximately 0.03% of 25(OH)D is free; 85% is bound to DBP, 15% is bound to albumin. The free hormone hypothesis postulates that only free 25(OH)D can enter cells. This hypothesis is supported by the observation that mice lacking DBP, and therefore with essentially undetectable 25(OH)D levels, do not show signs of vitamin D deficiency unless put on a vitamin D deficient diet. Similar observations have recently been described in a family with a DBP mutation. This hypothesis also applies to other protein bound lipophilic hormones including glucocorticoids, sex steroids, and thyroid hormone. However, tissues expressing the megalin/cubilin complex, such as the kidney, have the capability of taking up 25(OH)D still bound to DBP, but most tissues rely on the free level. Attempts to calculate the free level using affinity constants generated in a normal individual along with measurement of DBP and total 25(OH)D have not accurately reflected directly measured free levels in a number of clinical conditions. In this review, we examine the impact of different clinical conditions as well as different DBP alleles on the relationship between total and free 25(OH)D, using only data in which the free 25(OH)D level was directly measured. The major conclusion is that a number of clinical conditions alter this relationship, raising the question whether measuring just total 25(OH)D might be misleading regarding the assessment of vitamin D status, and such assessment might be improved by measuring free 25(OH)D instead of or in addition to total 25(OH)D.
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Affiliation(s)
- Daniel David Bikle
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Endocrine Research Unit, San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States
- *Correspondence: Daniel David Bikle
| | - Janice Schwartz
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
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Jorde R. The Role of Vitamin D Binding Protein, Total and Free 25-Hydroxyvitamin D in Diabetes. Front Endocrinol (Lausanne) 2019; 10:79. [PMID: 30837950 PMCID: PMC6389604 DOI: 10.3389/fendo.2019.00079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/30/2019] [Indexed: 12/16/2022] Open
Abstract
Vitamin D is important for bone health, but may also have extra-skeletal effects. Vitamin D and its binding protein DBP have immunological effects and may therefore be important in the development of type 1 diabetes (T1DM), and low serum levels of 25-hydroxyvitamin D (25(OH)D) are associated with later development of type 2 diabetes (T2DM). However, it has so far been difficult to convincingly show an effect of vitamin D supplementation on prevention or treatment of diabetes. The serum level of 25(OH)D has traditionally been used as a marker of a subject's vitamin D status. This measurement includes both 25(OH)D bound to DBP and albumin as well as the free from of 25(OH)D. However, according to the free hormone hypothesis, the free form is the biologically active. Previously the free form of 25(OH)D had to be calculated based on measurements of 25(OH)D, DBP, and albumin, but recently a method for direct measurement of free 25(OH)D has become commercially available. This is important in clinical conditions where the amount of DBP is affected, and has caused a renewed interest in which vitamin D metabolite to measure in clinical situations. In the present review the relations between DBP, total and free 25(OH)D in T1DM and T2DM are described.
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Affiliation(s)
- Rolf Jorde
- Tromsø Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
- Division of Internal Medicine, University Hospital of North Norway, Tromsø, Norway
- *Correspondence: Rolf Jorde
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Abstract
The last decade has seen a dramatic increase in general interest in and research into vitamin D, with many athletes now taking vitamin D supplements as part of their everyday dietary regimen. The most recognized role of vitamin D is its regulation of calcium homeostasis; there is a strong relationship between vitamin D and bone health in non-athletic individuals. In contrast, data have consistently failed to demonstrate any relationship between serum 25[OH]D and bone health, which may in part be due to the osteogenic stimulus of exercise. Vitamin D may interact with extra-skeletal tissues such as muscle and the immune system to modulate recovery from damaging exercise and infection risk. Given that many athletes now engage in supplementation, often consuming extreme doses of vitamin D, it is important to assess whether excessive vitamin D can be detrimental to health. It has been argued that toxic effects only occur when serum 25[OH]D concentrations are greater than 180 nmol·l-1, but data from our laboratory have suggested high-dose supplementation could be problematic. Finally, there is a paradoxical relationship between serum 25[OH]D concentration, ethnicity, and markers of bone health: Black athletes often present with low serum 25[OH]D without physiological consequences. One explanation for this could be genetic differences in vitamin D binding protein due to ethnicity, resulting in greater concentrations of bioavailable (or free) vitamin D in some ethnic groups. In the absence of any pathology, screening may be unnecessary and could result in incorrect supplementation. Data must now be re-examined, taking into consideration bioavailable or "free" vitamin D in ethnically diverse groups to enable new thresholds and target concentrations to be established; perhaps, for now, it is time to "set vitamin D free".
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Affiliation(s)
- Daniel J Owens
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Tom Reilly Building, Byrom Street, Liverpool, L3 3AF, UK
| | - Richard Allison
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Tom Reilly Building, Byrom Street, Liverpool, L3 3AF, UK.,Exercise and Sport Science Department, ASPETAR, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.,Arsenal Football Club, Bell Lane, London Colney, St Albans, Shenley, AL2 1DR, UK
| | - Graeme L Close
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Tom Reilly Building, Byrom Street, Liverpool, L3 3AF, UK.
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Schwartz JB, Gallagher JC, Jorde R, Berg V, Walsh J, Eastell R, Evans AL, Bowles S, Naylor KE, Jones KS, Schoenmakers I, Holick M, Orwoll E, Nielson C, Kaufmann M, Jones G, Bouillon R, Lai J, Verotta D, Bikle D. Determination of Free 25(OH)D Concentrations and Their Relationships to Total 25(OH)D in Multiple Clinical Populations. J Clin Endocrinol Metab 2018; 103:3278-3288. [PMID: 29955795 PMCID: PMC6126881 DOI: 10.1210/jc.2018-00295] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/21/2018] [Indexed: 11/19/2022]
Abstract
Context The optimal measure of vitamin D status is unknown. Objective To directly measure circulating free 25-hydroxyvitamin D [25(OH)D] concentrations and relationships to total 25(OH)D in a clinically diverse sample of humans. Design Cross-sectional analysis. Setting Seven academic sites. Patients A total of 1661 adults: healthy (n = 279), prediabetic (n = 479), outpatients (n = 714), cirrhotic (n = 90), pregnant (n = 20), nursing home resident (n = 79). Interventions Merge research data on circulating free 25(OH)D (directly-measured immunoassay), total 25(OH)D (liquid chromatography/tandem mass spectrometry), D-binding protein [DBP; by radial (polyclonal) immunodiffusion assay], albumin, creatinine, intact parathyroid hormone, and DBP haplotype. Main outcome measures Distribution of free 25(OH)D (ANOVA with Bonferroni correction for post hoc comparisons) and relationships between free and total 25(OH)D (mixed-effects modeling incorporating clinical condition, DBP haplotype with sex, race, estimated glomerular filtration rate (eGFR), body mass index (BMI), and other covariates). Results Free 25(OH)D was 4.7 ± 1.8 pg/mL (mean ± SD) in healthy persons and 4.3 ± 1.9 pg/mL in outpatients, with levels of 0.5 to 8.1 pg/mL and 0.9 to 8.1 pg/mL encompassing 95% of healthy persons and outpatients, respectively. Free 25(OH)D was higher in patients with cirrhosis (7.1 ± 3.0 pg/mL; P < 0.0033) and nursing home residents (7.9 ± 2.1 pg/mL; P < 0.0033) than in other groups and differed between whites and blacks (P < 0.0033) and between DBP haplotypes (P < 0.0001). Mixed-effects modeling of relationships between free and total 25(OH)D identified clinical conditions (patients with cirrhosis > nursing home residents > patients with prediabetes > outpatients > pregnant women) and BMI (lesser effect) as covariates affecting relationships but not eGFR, sex, race, or DBP haplotype. Conclusions Total 25(OH)D, health condition, race, and DBP haplotype affected free 25(OH)D, but only health conditions and BMI affected relationships between total and free 25(OH)D. Clinical importance of free 25(OH)D needs to be established in studies assessing outcomes.
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Affiliation(s)
- Janice B Schwartz
- Department of Medicine, University of California, San Francisco, California
| | | | - Rolf Jorde
- Tromso Endocrine Research Group, UiT the Arctic University of Norway, Tromsø, Norway
- Division of Internal Medicine, University Hospital of North Norway, Tromsø, Norway
| | - Vivian Berg
- Division of Internal Medicine, University Hospital of North Norway, Tromsø, Norway
| | - Jennifer Walsh
- Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Richard Eastell
- Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Amy L Evans
- Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Simon Bowles
- Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Kim E Naylor
- Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Kerry S Jones
- MRC Elsie Widdowson Laboratory, Cambridge, United Kingdom
| | - Inez Schoenmakers
- MRC Elsie Widdowson Laboratory, Cambridge, United Kingdom
- Department of Medicine, Norwich Medical School, Faculty of Medicine and Health Sciences, Norwich, United Kingdom
- University of East Anglia, Norwich, United Kingdom
| | - Michael Holick
- Boston University School of Medicine, Boston, Massachusetts
| | - Eric Orwoll
- Oregon Health and Science University, Portland, Oregon
| | | | | | | | | | - Jennifer Lai
- Department of Medicine, University of California, San Francisco, California
| | - Davide Verotta
- Departments of Bioengineering and Therapeutic Sciences and Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California
| | - Daniel Bikle
- Department of Medicine, University of California, San Francisco, California
- Department of Dermatology, University of California, San Francisco, San Francisco, California
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Lopez-Molina M, Santillan C, Murillo M, Valls A, Bosch L, Bel J, Granada ML. Measured free 25-hydroxyvitamin D in healthy children and relationship to total 25-hydroxyvitamin D, calculated free 25-hydroxyvitamin D and vitamin D binding protein. Clin Biochem 2018; 61:23-27. [PMID: 30130523 DOI: 10.1016/j.clinbiochem.2018.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/03/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND vitamin D deficiency in children is still a global health problem. Measuring free 25-hydroxyvitamin D concentrations could provide a better estimate of the vitamin D status than total 25-hydroxyvitamin D (25(OH)D) levels. OBJECTIVE To assess the relationship between measured free vitamin D (m-f25(OH)D) and calculated free 25(OH)D (c-f25(OH)D), total 25(OH)D, intact parathyroid hormone (iPTH) and other markers of phosphocalcic metabolism. To establish serum m-f25(OH)D concentrations corresponding to a total 25(OH)D > 50 nmol/L which is accepted as vitamin D-sufficiency status in children. DESIGN Prospective cohort study. SETTING January and February 2017 in a Mediterranean population. PATIENTS healthy children. MEASUREMENTS m-f25(OH)D and vitamin D binding protein (VDBP) by ELISA. Free 25(OH)D was calculated using the formula described by Bikle. RESULTS m-f25(OH)D directly correlated with total 25(OH)D (r:0.804,p < .001), serum calcium (r:0.26,p:0.035), and c-f25(OH)D (r:0.553,p:0.016); and inversely with iPTH (r:-0.374, p:0.002), alkaline phosphatase (r:-0.28, p:0.026), and age (r:-0.289, p:0.018). Total 25(OH)D correlated with the same parameters as m-f25(OH)D except for serum calcium. However, c-f25(OH)D correlated only with total 25(OH)D and VDBP, both included in the calculation formula. Multiple regression analysis showed that m-f25(OH)D variations were independently explained by calcium (β:0.156, p:0.026) and total 25(OH)D (β:0.043, p < .001). The optimal m-f25(OH)D cut-off for discriminating between insufficient and sufficient total 25(OH)D was >9.8 pmol/L (Area Under Curve (AUC): 0.897 (95% confidence interval (CI): (0.798-0.958); p < .001; sensitivity:72.7% (95%CI: 49.8-89.3); specificity: 95.5% (95%CI: 84.5-99.4)). CONCLUSIONS Directly measured free vitamin D correlated better with markers of phosphocalcic metabolism than total 25(OH)D and c-f25(OH)D in a population of healthy children.
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Affiliation(s)
- Maria Lopez-Molina
- Clinical Analysis and Biochemistry Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain.
| | - Cecilia Santillan
- Paediatrics Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain
| | - Marta Murillo
- Paediatrics Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain
| | - Aina Valls
- Paediatrics Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain
| | - Laura Bosch
- Paediatrics Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain
| | - Joan Bel
- Paediatrics Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain
| | - María Luisa Granada
- Clinical Analysis and Biochemistry Department, Germans Trias i Pujol University Hospital, Badalona, Universitat Autònoma Barcelona, Spain
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Michaëlsson K, Rasmusson A, Wolk A, Byberg L, Mitchell A, Melhus H. The Free Hormone Hypothesis: Is Free Serum 25-Hydroxyvitamin D a Better Marker for Bone Mineral Density in Older Women? JBMR Plus 2018; 2:367-374. [PMID: 30460340 PMCID: PMC6237208 DOI: 10.1002/jbm4.10059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 11/09/2022] Open
Abstract
It is presently unclear whether free serum 25‐hydroxyvitamin D (S‐25(OH)D) better reflects bone health than total S‐25(OH)D. We have previously shown that summer total S‐25(OH)D values are more useful to predict bone mineral density (BMD) than winter values. Our objective was therefore to compare the relative importance of free and total S‐25(OH)D for BMD by season. BMD was measured by dual‐energy X‐ray absorptiometry (DXA) in 5002 Swedish women (mean age 68 years) randomly selected from a large population‐based longitudinal cohort study. Free S‐25(OH)D was analyzed by a commercial ELISA and total S‐25(OH)D by HPLC–tandem mass spectrometry (MS/MS). Free and total S‐25(OH)D co‐varied with season, with 26% and 29% higher values in August compared with those in January–March (nadir). There were no differences in mean BMD between categories of free or total S‐25(OH)D in samples collected during winter. Women with higher total S‐25(OH)D measured during summer had higher BMD at the total hip. Compared with women who had total S‐25(OH)D values above 80 nmol/L during summer, adjusted BMD at the total hip was 6% (95% CI, 1% to 11%) lower for S‐25(OH)D concentrations between 30 and 40 mmol/L, and 11% (95% CI, 3% to 19%) lower for those with total S‐25(OH)D <30 nmol/L. In contrast, free S‐25(OH)D measured during summer was not associated with BMD. Compared with women who had highest free S‐25(OH)D measured during summer (>8.8 pmol/L), those with intermediate (2.4–3.5 pmol/L) and lowest (<2.4 pmol/L) free S‐25(OH)D during summer did not have lower total hip BMD values (3% [95% CI, −2% to 7%] and −2% [95% CI, −8% to 4%]). In addition, we found no added value for the prediction of BMD with the combined measurement of total and free S‐25(OH)D during summer or winter. We conclude that vitamin D status assessed by direct measurements of free S‐25(OH)D does not reflect BMD better than total S‐25(OH)D. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Karl Michaëlsson
- Department of Surgical Sciences Uppsala University Uppsala Sweden
| | - Annica Rasmusson
- Department of Medical Sciences Uppsala University Uppsala Sweden
| | - Alicja Wolk
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
| | - Liisa Byberg
- Department of Surgical Sciences Uppsala University Uppsala Sweden
| | - Adam Mitchell
- Department of Surgical Sciences Uppsala University Uppsala Sweden
| | - Håkan Melhus
- Department of Medical Sciences Uppsala University Uppsala Sweden
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von Websky K, Hasan AA, Reichetzeder C, Tsuprykov O, Hocher B. Impact of vitamin D on pregnancy-related disorders and on offspring outcome. J Steroid Biochem Mol Biol 2018; 180:51-64. [PMID: 29169993 DOI: 10.1016/j.jsbmb.2017.11.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/15/2017] [Accepted: 11/20/2017] [Indexed: 12/16/2022]
Abstract
Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for preeclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.
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Affiliation(s)
- Karoline von Websky
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Center for Cardiovascular Research, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ahmed Abdallah Hasan
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Department of Biochemistry, Faculty of Pharmacy, Zagazig University, Egypt
| | - Christoph Reichetzeder
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Center for Cardiovascular Research, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Oleg Tsuprykov
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Institute for Laboratory Medicine, IFLB, Berlin, Germany
| | - Berthold Hocher
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany; Institute for Laboratory Medicine, IFLB, Berlin, Germany; Department of Basic Medicine, Medical College of Hunan Normal University, Changsha, China.
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Tsuprykov O, Chen X, Hocher CF, Skoblo R, Hocher B. Why should we measure free 25(OH) vitamin D? J Steroid Biochem Mol Biol 2018; 180:87-104. [PMID: 29217467 DOI: 10.1016/j.jsbmb.2017.11.014] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/30/2017] [Accepted: 11/30/2017] [Indexed: 11/21/2022]
Abstract
Vitamin D, either in its D2 or D3 form, is essential for normal human development during intrauterine life, kidney function and bone health. Vitamin D deficiency has also been linked to cancer development and some autoimmune diseases. Given this huge impact of vitamin D on human health, it is important for daily clinical practice and clinical research to have reliable tools to judge on the vitamin D status. The major circulating form of vitamin D is 25-hydroxyvitamin D (25(OH)D), although it is not the most active metabolite, the concentrations of total 25-hydroxyvitamin D in the serum are currently routinely used in clinical practice to assess vitamin D status. In the circulation, vitamin D - like other steroid hormones - is bound tightly to a special carrier - vitamin D-binding protein (DBP). Smaller amounts are bound to blood proteins - albumin and lipoproteins. Only very tiny amounts of the total vitamin D are free and potentially biologically active. Currently used vitamin D assays do not distinguish between the three forms of vitamin D - DBP-bound vitamin D, albumin-bound vitamin D and free, biologically active vitamin D. Diseases or conditions that affect the synthesis of DBP or albumin thus have a huge impact on the amount of circulating total vitamin D. DBP and albumin are synthesized in the liver, hence all patients with an impairment of liver function have alterations in their total vitamin D blood concentrations, while free vitamin D levels remain mostly constant. Sex steroids, in particular estrogens, stimulate the synthesis of DBP. This explains why total vitamin D concentrations are higher during pregnancy as compared to non-pregnant women, while the concentrations of free vitamin D remain similar in both groups of women. The vitamin D-DBP as well as vitamin D-albumin complexes are filtered through the glomeruli and re-uptaken by megalin in the proximal tubule. Therefore, all acute and chronic kidney diseases that are characterized by a tubular damage, are associated with a loss of vitamin D-DBP complexes in the urine. Finally, the gene encoding DBP protein is highly polymorphic in different human racial groups. In the current review, we will discuss how liver function, estrogens, kidney function and the genetic background might influence total circulating vitamin D levels and will discuss what vitamin D metabolite is more appropriate to measure under these conditions: free vitamin D or total vitamin D.
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Affiliation(s)
- Oleg Tsuprykov
- IFLB, Institute for Laboratory Medicine, Berlin, Berlin, Germany; Institute of Nutritional Sciences, University of Potsdam, Potsdam, Germany
| | - Xin Chen
- Departments of Embryology and Nephrology, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Carl-Friedrich Hocher
- Departments of Embryology and Nephrology, The First Affiliated Hospital, Jinan University, Guangzhou, China; First Medical Faculty, Charles University of Prague, Prague, Czech Republic
| | - Roman Skoblo
- IFLB, Institute for Laboratory Medicine, Berlin, Berlin, Germany
| | - Berthold Hocher
- Institute of Nutritional Sciences, University of Potsdam, Potsdam, Germany; Departments of Embryology and Nephrology, The First Affiliated Hospital, Jinan University, Guangzhou, China.
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41
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The relationship between Vitamin D status and exacerbation in COPD patients– a literature review. Respir Med 2018; 139:34-38. [DOI: 10.1016/j.rmed.2018.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 02/20/2018] [Accepted: 04/18/2018] [Indexed: 01/09/2023]
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Pilz S, Obeid R, Schwetz V, Trummer C, Pandis M, Lerchbaum E, Pieber TR, Obermayer-Pietsch B, Wilhelm M, Hahn A, Schön C. Hormonal Contraceptive Use Is Associated With Higher Total but Unaltered Free 25-Hydroxyvitamin D Serum Concentrations. J Clin Endocrinol Metab 2018; 103:2385-2391. [PMID: 29672719 DOI: 10.1210/jc.2018-00336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 04/11/2018] [Indexed: 11/19/2022]
Abstract
CONTEXT Intake of hormonal contraceptives (HC) is associated with higher total 25-hydroxyvitamin D [25(OH)D] concentrations, but the effect of HC on free 25(OH)D is unclear. OBJECTIVE We investigated whether free 25(OH)D concentrations differ according to use of HC. DESIGN This is a post hoc analysis of a randomized open trial. SETTING This study was conducted from 13 January to 9 May, 2016, at a clinical research organization in Esslingen, Germany. PARTICIPANTS We included 201 apparently healthy women of childbearing age. INTERVENTION Participants were randomly assigned to receive a daily multimicronutrient supplement for 8 weeks; the supplement contained 200 IU (n =100) or 800 IU (n = 101) of vitamin D3. MAIN OUTCOME MEASURES Primary outcome was the difference in free 25(OH)D between users and nonusers of HC. RESULTS Overall, 176 participants [median (25th to 75th percentiles) age: 25 (22 to 29) years] with available free 25(OH)D were included in the present analysis. At baseline, total 25(OH)D was significantly higher in users (n = 110) than in nonusers (n = 66) of HC [49.2 (33.4 to 63.4) vs 39.1 (23.8 to 52.5) nmol/L; P < 0.001], whereas there was no difference in free 25(OH)D [7.87 (6.50 to 10.11) vs 7.88 (6.35 to 10.12) pmol/L; P = 0.923]. These results were confirmed after multimicronutrient supplementation and in subgroups according to treatment allocation. CONCLUSIONS Use of HC was associated with, on average, 26% higher total 25(OH)D, whereas free 25(OH)D values did not differ according to use of HC. These findings are relevant for epidemiological studies, but the physiological implications remain to be clarified.
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Affiliation(s)
- Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Rima Obeid
- Department of Clinical Chemistry, Saarland University Hospital, Homburg, Germany
| | - Verena Schwetz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Christian Trummer
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Marlene Pandis
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Elisabeth Lerchbaum
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Thomas R Pieber
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
- Center for Biomarker Research in Medicine, Graz, Austria
| | - Barbara Obermayer-Pietsch
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
- Center for Biomarker Research in Medicine, Graz, Austria
| | - Manfred Wilhelm
- Department of Mathematics, Natural and Economic Sciences, University of Applied Sciences Ulm, Ulm, Germany
| | - Andreas Hahn
- 5Institute of Food Science and Human Nutrition, Leibniz University of Hannover, Hannover, Germany
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Hong K, Florkowski CM, Doogue MP, Elder PA, Lewis JG. A monoclonal antibody sandwich ELISA for vitamin D-binding protein (VDBP) is unaffected by Gc-globulin phenotype peptides and actin and demonstrates reduced levels in sepsis and non-sepsis intensive care patients. Clin Chim Acta 2018; 484:7-13. [PMID: 29775620 DOI: 10.1016/j.cca.2018.05.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 11/29/2022]
Abstract
The measurement of vitamin D-binding protein (VDBP) by immunoassay has been confounded by variable antibody recognition of the Gc1s, Gc1F and Gc2 phenotypes. This has led to spurious conclusions regarding vitamin D status in different ethnic groups. In order to overcome these problems there is a requirement for VDBP antibodies that are unaffected by phenotype status. Here we report the generation and testing of three monoclonal antibodies to VDBP which recognise linear epitopes and are unaffected by vast molar excesses of synthetic peptides spanning these phenotypic domains. These IgG1 kappa antibodies were purified and biotinylated to allow suitable pairings to develop a sandwich ELISA for circulating VDBP. The VDBP ELISA is unaffected by actin and confirms that VDBP levels are significantly reduced in sepsis patients and non-sepsis intensive care patients compared to normal healthy subjects. Levels of VDBP along with total 25OH vitamin D3 can be used to calculate free 25OH vitamin D3 levels and these compare well with consensus values determined independently. The VDBP ELISA meets acceptable performance criteria and as such can be used in conjunction with total 25OH vitamin D3 to determine the free 25OH vitamin D3 status in various cohorts.
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Affiliation(s)
- Katrina Hong
- Endocrinology and Steroid Laboratory, Canterbury Health Laboratories, New Zealand
| | | | - Matthew P Doogue
- Department of Pharmacology, Christchurch Hospital, Christchurch, New Zealand
| | - Peter A Elder
- Endocrinology and Steroid Laboratory, Canterbury Health Laboratories, New Zealand
| | - John G Lewis
- Endocrinology and Steroid Laboratory, Canterbury Health Laboratories, New Zealand.
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Alterations in the vitamin D endocrine system during pregnancy: A longitudinal study of 855 healthy Norwegian women. PLoS One 2018; 13:e0195041. [PMID: 29641551 PMCID: PMC5895009 DOI: 10.1371/journal.pone.0195041] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 03/14/2018] [Indexed: 12/11/2022] Open
Abstract
To ensure optimal calcium accrual in the fetal skeleton, a substantial rise occurs in 1,25-dihydroxyvitamin D (1,25(OH)2D), but is dependent on sufficient 25-hydroxyvitamin (25(OH)D). Large longitudinal studies addressing free 25(OH)D and 1,25(OH)2D during pregnancy are scarce. We aimed to assess levels of and relationship between 25(OH)D, 1,25(OH)2D, vitamin D-binding protein (DBP), parathyroid hormone (PTH), and free 25(OH)D during pregnancy; determinants of vitamin D status; and association between vitamin D indices or PTH and pregnancy outcomes (gestational diabetes mellitus and birthweight). Altogether 855 pregnant Norwegian Caucasian women from Trondheim and Stavanger (latitude 63°N and 58°N) were recruited; 94 were lost to follow-up. The study was originally a randomized controlled trial (2007-2009) with gestational diabetes as primary outcome. Data were collected in second and third trimester. In third trimester, 246 (34%) had vitamin D insufficiency and 52 (7%) deficiency (25(OH)D <50 and <30nmol/L, respectively). During wintertime in third trimester, 61 (47%) from Trondheim and 23 (51%) from Stavanger exhibited vitamin D insufficiency. PTH was elevated in 27 (3.7%). Estimate of change between trimesters was (95% CI): 25(OH)D -1.8 (-2.8 to -0.7) nmol/L, DBP 0.62 (0.57 to 0.66) μmol/L, calculated free 25(OH)D -1.7 (-2.0 to -1.4) pmol/L, PTH 0.81 (0.72 to 0.90) pmol/L, 1,25(OH)2D (sub-analysis) 31.4 (CI 24.7 to 38.2) pmol/L. A decrease in 1,25(OH)2D occurred in 45% of those with vitamin D deficiency, and they also exhibited lower levels than women with adequate vitamin D status. No association of vitamin D indices and PTH with pregnancy outcomes was observed. Women in Trondheim displayed lower 25(OH)D levels, despite minor latitudinal differences. Less than one-fifth adhered to the authorities' vitamin D recommendations. These findings demonstrate that hypovitaminosis D is prevalent among pregnant women living in northern latitudes, especially during the dark season, and there is an unmet need to ensure adequate vitamin D intake.
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C3-epimerization of 25-hydroxyvitamin D increases with increasing serum 25-hydroxyvitamin D levels and shows a high degree of tracking over time. Clin Biochem 2018; 54:61-67. [DOI: 10.1016/j.clinbiochem.2018.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/14/2018] [Accepted: 02/20/2018] [Indexed: 01/17/2023]
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Jukic AMZ, Hoofnagle AN, Lutsey PL. Measurement of Vitamin D for Epidemiologic and Clinical Research: Shining Light on a Complex Decision. Am J Epidemiol 2018; 187:879-890. [PMID: 29020155 DOI: 10.1093/aje/kwx297] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 08/03/2017] [Indexed: 01/08/2023] Open
Abstract
Vitamin D is a fat-soluble vitamin that is synthesized in the skin with exposure to sunlight or is ingested from dietary supplements or food. There has been a dramatic increase in research on vitamin D, linking it with health outcomes as varied as reproductive function, infection, cardiovascular disease, and cancer. The study of vitamin D has generated much excitement, partly because there is an ideal intervention: Low levels may be common and can be remedied with widely available supplements. Determination of vitamin D status is complex and has advanced dramatically in the past 5 years. In this paper, we begin by describing important considerations for measurement of total 25-hydroxyvitamin D (25(OH)D), the biomarker traditionally assessed in epidemiologic studies. While 25(OH)D remains the most commonly measured biomarker, emerging evidence suggests that other related analytes may contribute to the characterization of an individual's vitamin D status (e.g., vitamin D-binding protein, bioavailable and free 25(OH)D, the C-3 epimer of 25(OH)D, 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D). The measurement of these analytes is also complex, and there are important considerations for deciding whether their measurement is warranted in new research studies. Herein we discuss these issues and provide the reader with an up-to-date synthesis of research on vitamin D measurement options and considerations.
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Affiliation(s)
- Anne Marie Z Jukic
- Department of Chronic Disease Epidemiology, Yale Center for Perinatal, Pediatric, and Environmental Epidemiology, Yale School of Public Health, New Haven, Connecticut
| | - Andrew N Hoofnagle
- Department of Laboratory Medicine, School of Medicine, University of Washington, Seattle, Washington
| | - Pamela L Lutsey
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota
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O'Brien KM, Sandler DP, Shi M, Harmon QE, Taylor JA, Weinberg CR. Genome-Wide Association Study of Serum 25-Hydroxyvitamin D in US Women. Front Genet 2018; 9:67. [PMID: 29545823 PMCID: PMC5838824 DOI: 10.3389/fgene.2018.00067] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/15/2018] [Indexed: 12/31/2022] Open
Abstract
Genetic factors likely influence individuals' concentrations of 25-hydroxyvitamin D [25(OH)D], a biomarker of vitamin D exposure previously linked to reduced risk of several chronic diseases. We conducted a genome-wide association study of serum 25(OH)D (assessed using liquid chromatography-tandem mass spectrometry) and 386,449 single nucleotide polymorphisms (SNPs). Our sample consisted of 1,829 participants randomly selected from the Sister Study, a cohort of women who had a sister with breast cancer but had never had breast cancer themselves. 19,741 SNPs were associated with 25(OH)D (p < 0.05). We re-assessed these hits in an independent sample of 1,534 participants who later developed breast cancer. After pooling, 32 SNPs had genome-wide significant associations (p < 5 × 10-8). These were located in or near GC, the vitamin D binding protein, or CYP2R1, a cytochrome P450 enzyme that hydroxylates vitamin D to form 25(OH)D. The top hit was rs4588, a missense GC polymorphism associated with a 3.5 ng/mL decrease in 25(OH)D per copy of the minor allele (95% confidence interval [CI]: -4.1, -3.0; p = 4.5 × 10-38). The strongest SNP near CYP2R1 was rs12794714, a synonymous variant (p = 3.8 × 10-12; β = 1.8 ng/mL decrease in 25(OH)D per minor allele [CI: -2.2, -1.3]). Serum 25(OH)D concentrations from samples collected from some participants 3-10 years after baseline (811 cases, 780 non-cases) were also strongly associated with both loci. These findings augment our understanding of genetic influences on 25(OH)D and the possible role of vitamin D binding proteins and cytochrome P450 enzymes in determining measured levels. These results may help to identify individuals genetically predisposed to vitamin D insufficiency.
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Affiliation(s)
- Katie M. O'Brien
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Dale P. Sandler
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Min Shi
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Quaker E. Harmon
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Jack A. Taylor
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Clarice R. Weinberg
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
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48
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Jorde R, Grimnes G. Exploring the association between serum 25-hydroxyvitamin D and serum lipids—more than confounding? Eur J Clin Nutr 2018; 72:526-533. [DOI: 10.1038/s41430-018-0088-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/28/2017] [Accepted: 12/20/2017] [Indexed: 12/31/2022]
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49
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Bikle DD, Malmstroem S, Schwartz J. Current Controversies: Are Free Vitamin Metabolite Levels a More Accurate Assessment of Vitamin D Status than Total Levels? Endocrinol Metab Clin North Am 2017; 46:901-918. [PMID: 29080642 PMCID: PMC5675107 DOI: 10.1016/j.ecl.2017.07.013] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The free hormone hypothesis postulates that only the nonbound fraction (the free fraction) of hormones that otherwise circulate in blood bound to their carrier proteins is able to enter cells and exert their biologic effects. For the vitamin D metabolites less than 1% (0.4% for 1,25(OH)2D and 0.03% for 25(OH)D) is free, with more than 99% bound to the vitamin D binding protein (DBP) and albumin (approximately 85% and 15%, respectively). Assays to measure the free vitamin D metabolite levels have been developed, and initial studies indicated their value in subjects with altered DBP levels.
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Affiliation(s)
- Daniel D Bikle
- Department of Medicine, University of California San Francisco, San Francisco VA Medical Center, 1700 Owens Street, San Francisco, CA 94158, USA.
| | - Sofie Malmstroem
- University of California San Francisco, 1700 Owens Street, San Francisco, CA 94158, USA; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Janice Schwartz
- University of California San Francisco, 1700 Owens Street, San Francisco, CA 94158, USA
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50
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Kilpatrick LE, Phinney KW. Quantification of Total Vitamin-D-Binding Protein and the Glycosylated Isoforms by Liquid Chromatography–Isotope Dilution Mass Spectrometry. J Proteome Res 2017; 16:4185-4195. [DOI: 10.1021/acs.jproteome.7b00560] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Lisa E. Kilpatrick
- National Institute of Standards and Technology, Material Measurement
Laboratory, Biomolecular Measurement Division, 100 Bureau Drive, Stop 8314, Gaithersburg, Maryland 20899, United States
| | - Karen W. Phinney
- National Institute of Standards and Technology, Material Measurement
Laboratory, Biomolecular Measurement Division, 100 Bureau Drive, Stop 8314, Gaithersburg, Maryland 20899, United States
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