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Fernández-Araque A, Giaquinta-Aranda A, Moreno-Sainz C, Martínez-Martínez MC, Velasco-González V, Sainz-Gil M, Martín-Arias LH, Carretero-Molinero S, García-Hidalgo M, Verde Z. Haplotypes in the GC, CYP2R1 and CYP24A1 Genes and Biomarkers of Bone Mineral Metabolism in Older Adults. Nutrients 2022; 14:259. [PMID: 35057442 PMCID: PMC8778395 DOI: 10.3390/nu14020259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 12/07/2022] Open
Abstract
Candidate gene studies have analyzed the effect of specific vitamin D pathway genes on vitamin D availability; however, it is not clear whether genetic variants also affect overall bone metabolism. This study evaluated the association between genetic polymorphisms in GC, CYP2R1 and CYP24A1 and serum levels of total 25(OH)D, iPTH and other mineral metabolism biomarkers (albumin, total calcium and phosphorus) in a sample of 273 older Spanish adults. We observed a significant difference between CYP2R1 rs10741657 codominant model and total 25(OH)D levels after adjusting them by gender (p = 0.024). In addition, the two SNPs in the GC gene (rs4588 and rs2282679) were identified significantly associated with iPTH and creatinine serum levels. In the case of phosphorus, we observed an association with GC SNPs in dominant model. We found a relationship between haplotype 2 and 25(OH)D levels, haplotype 4 and iPTH serum levels and haplotype 7 and phosphorus levels. In conclusion, genetic variants in CYP2R1 and GC could be predictive of 25(OH)D and iPTH serum levels, respectively, in older Caucasian adults. The current study confirmed the role of iPTH as one of the most sensitive biomarkers of vitamin D activity in vivo.
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Affiliation(s)
- Ana Fernández-Araque
- Department of Nursery, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain; (A.F.-A.); (A.G.-A.); (S.C.-M.)
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
| | - Andrea Giaquinta-Aranda
- Department of Nursery, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain; (A.F.-A.); (A.G.-A.); (S.C.-M.)
- Department of Hemodialysis, Hospital Santa Bárbara, 42005 Soria, Spain
| | - Carmelo Moreno-Sainz
- Department of Clinic Biochemistry, Hospital Santa Bárbara, 42005 Soria, Spain; (C.M.-S.); (M.C.M.-M.)
| | | | - Verónica Velasco-González
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Department of Nursery, University of Valladolid, 47005 Valladolid, Spain
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
| | - María Sainz-Gil
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
- Centro de Estudios sobre la Seguridad de los Medicamentos (CESME), University of Valladolid, 47005 Valladolid, Spain
| | - Luis H. Martín-Arias
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
- Centro de Estudios sobre la Seguridad de los Medicamentos (CESME), University of Valladolid, 47005 Valladolid, Spain
| | - Silvia Carretero-Molinero
- Department of Nursery, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain; (A.F.-A.); (A.G.-A.); (S.C.-M.)
| | | | - Zoraida Verde
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
- Departamento de Bioquímica, Biología Molecular y Fisiología, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain
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Çelik N, Doğan HO, Zararsiz G. Different threshold levels of circulating total and free 25-hydroxyvitamin D for the diagnosis of vitamin D deficiency in obese adolescents. Eur J Pediatr 2021; 180:2619-2627. [PMID: 34117551 DOI: 10.1007/s00431-021-04137-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/26/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
The total serum 25-hydroxyvitamin D [25(OH)DT] level is lower in obese individuals than in their nonobese peers, despite similar bone turnover markers and bone mineral density. This study aimed to investigate whether the threshold level of 25(OH)D for the diagnosis of vitamin D deficiency (VDD) in obese adolescents was lower than that in controls and to compare 25(OH)DT, free [25(OH)DF] and bioavailable [25(OH)DB] vitamin D with VDBP levels in obese individuals and their controls. A total of 173 adolescents (90 obese individuals and 83 controls) aged 12-18 years were included in the study. The metabolic and anthropometric parameters of the participants were recorded, the 25(OH)DT, 25(OH)DF, and VDBP levels were measured, and the 25(OH)DB levels were calculated. The cutoff values for VDD were estimated according to the level of 25(OH)D below which parathyroid hormone begins to rise. The obese subjects had lower 25(OH)DT (12.1 ± 5.8 vs. 16.4 ± 9.3 ng/mL, p < 0.001), 25(OH)DF (12.6 ± 4.2 vs. 16.7 ± 7.6 pg/mL, p < 0.001), 25(OH)DB [4.8 (2.3) vs. 6.1 (5.2) ng/mL, p = 0.012], and VDBP [112.2 (51.3) vs. 121.9 (95.5) μg/mL, p < 0.001] levels than the controls. The cutoff values for 25(OH)DT and 25(OH)DF levels for VDD were lower in the obese group than in the control group (9.4 vs. 14.1 ng/mL; 12.2 vs. 16.8 pg/mL, respectively).Conclusion: The vitamin D cutoff values for the diagnosis of VDD were different in the obese and control groups. Using the same cutoff value for VDD may cause overtreatment in obese adolescents. What is Known: • Vitamin D deficiency is more prevalent in obese children than nonobese controls, despite the same bone turnover markers and bone mineral density • The cutoff value of vitamin D level for the diagnosis of VDD is based on the PTH elevation What is New: • In obese adolescents, total and free vitamin D cutoff value for the diagnosis of VDD was lower than nonobese peers • Using the same cutoff value for vitamin D deficiency in both obese and nonobese adolescents may cause overtreatment.
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Affiliation(s)
- Nurullah Çelik
- Division of Pediatric Endocrinology, Department of Pediatrics, Faculty of Medicine, Cumhuriyet University, Eğri Köprü Mah. Koç Platform Sitesi, A-Blok No: 15, Sivas, Türkiye.
| | - Halef Okan Doğan
- Department of Biochemistry, Faculty of Medicine, Cumhuriyet University, Sivas, Turkey
| | - Gökmen Zararsiz
- Department of Biostatistics, Faculty of Medicine, Erciyes University, Kayseri, Turkey.,Erciyes University Drug Application and Research Center, PMAA Research Group, Kayseri, Turkey
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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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Mølmen KS, Hammarström D, Pedersen K, Lian Lie AC, Steile RB, Nygaard H, Khan Y, Hamarsland H, Koll L, Hanestadhaugen M, Eriksen AL, Grindaker E, Whist JE, Buck D, Ahmad R, Strand TA, Rønnestad BR, Ellefsen S. Vitamin D 3 supplementation does not enhance the effects of resistance training in older adults. J Cachexia Sarcopenia Muscle 2021; 12:599-628. [PMID: 33788419 PMCID: PMC8200443 DOI: 10.1002/jcsm.12688] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 12/30/2020] [Accepted: 01/26/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. METHODS Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments. RESULTS Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study. CONCLUSIONS Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD.
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Affiliation(s)
- Knut Sindre Mølmen
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Daniel Hammarström
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Karianne Pedersen
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Anne Cecilie Lian Lie
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Ragnvald B. Steile
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Håvard Nygaard
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Yusuf Khan
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
- Department of BiotechnologyInland Norway University of Applied SciencesHamarNorway
| | - Håvard Hamarsland
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Lise Koll
- Innlandet Hospital TrustLillehammerNorway
| | | | | | - Eirik Grindaker
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | | | - Daniel Buck
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Rafi Ahmad
- Department of BiotechnologyInland Norway University of Applied SciencesHamarNorway
- Institute of Clinical Medicine, Faculty of Health SciencesUiT – The Arctic University of NorwayTromsøNorway
| | - Tor A. Strand
- Innlandet Hospital TrustLillehammerNorway
- Centre for International HealthUniversity of BergenBergenNorway
| | - Bent R. Rønnestad
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Stian Ellefsen
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
- Innlandet Hospital TrustLillehammerNorway
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Galuška D, Pácal L, Kaňková K. Pathophysiological Implication of Vitamin D in Diabetic Kidney Disease. Kidney Blood Press Res 2021; 46:152-161. [PMID: 33756482 DOI: 10.1159/000514286] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/24/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Vitamin D is a hormone regulating not only calcium and phosphate homeostasis but also, at the same time, exerting many other extraskeletal functions via genomic effects (gene transcription) and probably by non-genomic effects as well. Availability is ensured by dietary intake of its precursors and by de novo production via sunlight. Yet, vitamin D deficiency and insufficiency are very common across the globe and are connected to many pathophysiological states, for example, diabetes mellitus, allergies, autoimmune diseases, pregnancy complications, and recently have also been associated with worse COVID-19 clinical outcomes. SUMMARY In this review, we summarize current knowledge about vitamin D metabolism in general, its role in diabetes mellitus (mainly type 2) and diabetic complications (mainly diabetic kidney disease), and potential therapeutic perspectives including vitamin D signalling as a druggable target. Key Messages: Vitamin D is not only a vitamin but also a hormone involved in many physiological processes. Its insufficiency or deficiency can lead to many pathological states.
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Affiliation(s)
- David Galuška
- Department of Pathophysiology, Faculty of Medicine, Masaryk University, Brno, Czechia,
| | - Lukáš Pácal
- Department of Pathophysiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Kateřina Kaňková
- Department of Pathophysiology, Faculty of Medicine, Masaryk University, Brno, Czechia
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The Origins of Salivary Vitamin A, Vitamin B 12 and Vitamin D-Binding Proteins. Nutrients 2020; 12:nu12123838. [PMID: 33339130 PMCID: PMC7765569 DOI: 10.3390/nu12123838] [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: 11/10/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 11/16/2022] Open
Abstract
Vitamin A- (retinol), vitamin B12- (haptocorrin) and vitamin D-binding proteins are the major circulatory transporters of their respective ligands; they are also constituents of the salivary proteome, the origins of which, remain unclear. The aim of this study was to explore how these proteins enter saliva and their relationship (if any) with vitamin status. Firstly, the three vitamin-binding proteins were quantified in resting whole mouth saliva and chewing-stimulated saliva from healthy donors (n = 10) to determine if they enter the mouth by salivary secretion or from the circulation. Secondly paired whole mouth saliva and serum samples were analysed from healthy donors (n = 14) to determine the relationships between the vitamin-binding proteins and vitamin status. Salivary output of all three vitamin-binding proteins studied increased when secretion was stimulated, suggesting they are secreted by the salivary glands. Whilst retinol-binding protein and haptocorrin were secreted by all major salivary glands, vitamin D-binding protein was restricted to the mucus glands. Salivary vitamin-binding protein concentrations were not found to be indicative of systemic vitamin status.
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Invited commentary in response to: Vitamin D 3 supplementation for 8 weeks leads to improved haematological status following the consumption of an iron-fortified breakfast cereal: a double-blind randomised controlled trial in iron-deficient women. Br J Nutr 2019; 122:603-604. [PMID: 31280725 DOI: 10.1017/s0007114519001569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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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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Vitamin D3 supplementation for 8 weeks leads to improved haematological status following the consumption of an iron-fortified breakfast cereal: a double-blind randomised controlled trial in iron-deficient women. Br J Nutr 2019; 121:1146-1157. [PMID: 30819262 DOI: 10.1017/s0007114519000412] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The effect of 38 µg (1500 IU) daily vitamin D3 supplementation, consumed with an Fe-fortified breakfast cereal for 8 weeks, on haematological indicators in Fe-deficient female subjects was investigated. Fifty Fe-deficient subjects (plasma ferritin concentration <20 µg/l; mean age: 27·4 (sd 9·4) years) were randomised to consume an Fe-fortified breakfast cereal containing 9 mg of Fe daily, with either a vitamin D3 supplement or placebo. Blood samples were collected at baseline, interim (4 weeks) and post-intervention (8 weeks) for measurement of Fe and vitamin D status biomarkers. The effect of intervention was analysed using mixed-model repeated-measures ANOVA. Significant increases were observed in two main haematological indices: Hb concentration and haematocrit level from baseline to post-intervention in the vitamin D group but not in the placebo group. The increase from baseline to post-intervention in Hb concentration in the vitamin D group (135 (sd 11) to 138 (sd 10) g/l) was significantly higher compared with the placebo group (131 (sd 15) to 128 (sd 13) g/l) (P=0·037). The increase in haematocrit level from baseline to post-intervention was also significantly higher in the vitamin D group (42·0 (sd 3·0) to 43·8 (sd 3·4) %) compared with the placebo group (41·2 (sd 4·3) to 40·7 (sd 3·6) %) (P=0·032). Despite the non-significant changes in plasma ferritin concentration, this study demonstrates that 38 µg supplemental vitamin D, consumed daily, with Fe-fortified breakfast cereal led to improvement in Hb concentration and haematocrit levels in women with low Fe stores. These findings may have therapeutic implications in the recovery of Fe status in Fe-deficient populations at a healthcare level.
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Aspelund T, Grübler MR, Smith AV, Gudmundsson EF, Keppel M, Cotch MF, Harris TB, Jorde R, Grimnes G, Joakimsen R, Schirmer H, Wilsgaard T, Mathiesen EB, Njølstad I, Løchen ML, März W, Kleber ME, Tomaschitz A, Grove-Laugesen D, Rejnmark L, Swart KMA, Brouwer IA, Lips P, van Schoor NM, Sempos CT, Durazo-Arvizu RA, Škrabáková Z, Dowling KG, Cashman KD, Kiely M, Pilz S, Gudnason V, Eiriksdottir G. Effect of Genetically Low 25-Hydroxyvitamin D on Mortality Risk: Mendelian Randomization Analysis in 3 Large European Cohorts. Nutrients 2019; 11:E74. [PMID: 30609725 PMCID: PMC6356674 DOI: 10.3390/nu11010074] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 12/13/2018] [Accepted: 12/24/2018] [Indexed: 12/19/2022] Open
Abstract
The aim of this study was to determine if increased mortality associated with low levels of serum 25-hydroxyvitamin D (25(OH)D) reflects a causal relationship by using a Mendelian randomisation (MR) approach with genetic variants in the vitamin D synthesis pathway. Individual participant data from three European cohorts were harmonized with standardization of 25(OH)D according to the Vitamin D Standardization Program. Most relevant single nucleotide polymorphisms of the genes CYP2R1 (rs12794714, rs10741657) and DHCR7/NADSYN1 (rs12785878, rs11234027), were combined in two allelic scores. Cox proportional hazards regression models were used with the ratio estimator and the delta method for calculating the hazards ratio (HR) and standard error of genetically determined 25(OH)D effect on all-cause mortality. We included 10,501 participants (50.1% females, 67.1±10.1 years) of whom 4003 died during a median follow-up of 10.4 years. The observed adjusted HR for all-cause mortality per decrease in 25(OH)D by 20 nmol/L was 1.20 (95% CI: 1.15⁻1.25). The HR per 20 nmol/L decrease in genetically determined 25(OH)D was 1.32 (95% CI: 0.80⁻2.24) and 1.35 (95% CI of 0.81 to 2.37) based on the two scores. In conclusion, the results of this MR study in a combined sample from three European cohort studies provide further support for a causal relationship between vitamin D deficiency and increased all-cause mortality. However, as the current study, even with ~10,000 participants, was underpowered for the study of the effect of the allele score on mortality, larger studies on genetics and mortality are needed to improve the precision.
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Affiliation(s)
- Thor Aspelund
- Icelandic Heart Association, 201 Kopavogur, Iceland.
- Faculty of Medicine, School of Health Sciences, University of Iceland, 101 Reykjavik, Iceland.
| | - Martin R Grübler
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria.
- Department of Cardiology, Medical University of Graz, 8036 Graz, Austria.
- Swiss Cardiovascular Center Bern, Department of Cardiology, Bern University Hospital, University of Bern, 3012 Bern, Switzerland.
| | - Albert V Smith
- Icelandic Heart Association, 201 Kopavogur, Iceland.
- Faculty of Medicine, School of Health Sciences, University of Iceland, 101 Reykjavik, Iceland.
| | | | - Martin Keppel
- Department of Laboratory Medicine, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - Mary Frances Cotch
- Division of Epidemiology and Clinical Applications, National Eye Institute, Bethesda, MD 20892-1204, USA.
| | - Tamara B Harris
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Bethesda, MD 20814, USA.
| | - Rolf Jorde
- Tromsø Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Guri Grimnes
- Tromsø Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Ragnar Joakimsen
- Tromsø Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Henrik Schirmer
- Tromsø Cardiovascular Research Group UNN, Department of Clinical Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Tom Wilsgaard
- Department of Community Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Ellisiv B Mathiesen
- Brain and Circulation Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
- Department of Neurology, University Hospital of North Norway, 9038 Tromsø, Norway.
| | - Inger Njølstad
- Department of Community Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Maja-Lisa Løchen
- Department of Community Medicine, UiT The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Winfried März
- Medical Clinic V, Mannheim Medical Faculty, University of Heidelberg, 68167 Mannheim, Germany.
- SYNLAB Academy, SYNLAB Holding Deutschland GmbH, P5, 7, D-68161 Mannheim or Gubener Straße 39, 86156 Augsburg, Germany.
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, 8036 Graz, Austria.
| | - Marcus E Kleber
- Medical Clinic V, Mannheim Medical Faculty, University of Heidelberg, 68167 Mannheim, Germany.
- NutriCard-Competence Cluster for Nutrition and Cardiovascular Health, Institute for Nutritional Science, Friedrich-Schiller-University, 07743 Jena, Germany.
| | - Andreas Tomaschitz
- Department of Cardiology, Medical University of Graz, 8036 Graz, Austria.
- Specialist Clinic for Rehabilitation Bad Aussee, 8990 Bad Aussee, Austria.
- Department of Internal Medicine-Cardiology, Charité University Hospital Berlin, Campus Virchow Klinikum, 10117 Berlin, Germany.
| | - Diana Grove-Laugesen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8200 Aarhus, Denmark.
| | - Lars Rejnmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8200 Aarhus, Denmark.
| | - Karin M A Swart
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Epidemiology and Biostatistics, Amsterdam Public Health, 1081 Amsterdam, The Netherlands.
| | - Ingeborg A Brouwer
- Department of Health Sciences, Faculty of Sciences and Amsterdam Public Health Research Institute, Vrije Universiteit Amsterdam, 1081 Amsterdam, The Netherlands.
| | - Paul Lips
- Department of Internal Medicine, Endocrine Section, VU University Medical Center, 1081 Amsterdam, The Netherlands.
| | - Natasja M van Schoor
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Epidemiology and Biostatistics, Amsterdam Public Health, 1081 Amsterdam, The Netherlands.
| | - Christopher T Sempos
- Office of Dietary Supplements, National Institute of Health, Bethesda, MD 20892-7517, USA.
| | - Ramón A Durazo-Arvizu
- Department of Public Health Sciences, Loyola University Stritch School of Medicine, Maywood, IL 60153, USA.
| | - Zuzana Škrabáková
- Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12K8AF, Ireland.
| | - Kirsten G Dowling
- Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12K8AF, Ireland.
| | - Kevin D Cashman
- Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12K8AF, Ireland.
- Department of Medicine, University College Cork, Cork T12K8AF, Ireland.
| | - Mairead Kiely
- Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12K8AF, Ireland.
- Irish Centre for Fetal and Neonatal Translational Research [INFANT], University College Cork, Cork T12K8AF, Ireland.
| | - Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria.
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Epidemiology and Biostatistics, Amsterdam Public Health, 1081 Amsterdam, The Netherlands.
| | - Vilmundur Gudnason
- Icelandic Heart Association, 201 Kopavogur, Iceland.
- Faculty of Medicine, School of Health Sciences, University of Iceland, 101 Reykjavik, Iceland.
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Prognostic Relevance of Circulating 25OHD Fractions for Early Recovery and Survival in Patients with Hip Fracture †. J Clin Med 2018; 7:jcm7080193. [PMID: 30071650 PMCID: PMC6111530 DOI: 10.3390/jcm7080193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/28/2018] [Accepted: 07/28/2018] [Indexed: 12/14/2022] Open
Abstract
The relation between vitamin-D (VD) status and healing after hip fracture had not been sufficiently addressed. Currently serum total 25-hydroxy-VD (t-25OHD) is the most widely used indicator of VD status. It is unclear whether free or bioavailable VD are better markers of 25OHD availability for tissues. Validity of overall cut-off values of t-25OHD is limited. OBJECTIVES (1) Assess serum levels of circulating forms of 25OHD in patients with hip fracture (PwHF: N = 199) compared to active controls without history of fracture (N = 102); (2) determine relationship between 25OHD fractions and functional performance after surgery (FPAS) and survival. The t-25OHD; VD binding protein and albumin levels were measured. Comorbidities; lifestyle; FPAS and survival were recorded at seven months. VD deficiency occurred more frequently in PwHF than in controls (72% vs. 38%). Patients with better FPAS showed higher 25OHD in all fractions than with poor FPAS. Controlled by lifestyle; 25OHD levels were independent predictive factors (p < 0.001). Good FPAS values forecasted longer survival (OR: 6.5CI:3.2⁻13.3; p < 0.0001). All 25OHD forms showed a tendency to predict survival. Mortality rate decreased to 8% in individuals with t-25OHD levels of >22.6⁻39.5 nmol/L and increased to 14% with >40 nmol/L. These observations highlight the importance of serum 25OHD assessment and moderate VD substitution for healing and survival.
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12
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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: 141] [Impact Index Per Article: 23.5] [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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13
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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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14
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Bikle D, Bouillon R, Thadhani R, Schoenmakers I. Vitamin D metabolites in captivity? Should we measure free or total 25(OH)D to assess vitamin D status? J Steroid Biochem Mol Biol 2017; 173:105-116. [PMID: 28093353 PMCID: PMC9005158 DOI: 10.1016/j.jsbmb.2017.01.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/31/2016] [Accepted: 01/10/2017] [Indexed: 01/03/2023]
Abstract
There is general consensus that serum 25(OH)D is the best biochemical marker for nutritional vitamin D status. Whether free 25(OH)D would be a better marker than total 25(OH)D is so far unclear. Free 25(OH)D can either be calculated based on the measurement of the serum concentrations of total 25(OH)D, vitamin D-binding protein (DBP), albumin, and the affinity between 25(OH)D and its binding proteins in physiological situations. Free 25(OH)D can also be measured directly by equilibrium dialysis, ultrafitration or immunoassays. During the vitamin D workshop held in Boston in March 2016, a debate was organized about the measurements and clinical value of free 25(OH)D, and this debate is summarized in the present manuscript. Overall there is consensus that most cells apart from the renal tubular cells are exposed to free rather than to total 25(OH)D. Therefore free 25(OH)D may be highly relevant for the local production and action of 1,25(OH)2D. During the debate it became clear that there is a need for standardization of measurements of serum DBP and of direct measurements of free 25(OH)D. There seems to be very limited genetic or racial differences in DBP concentrations or (probably) in the affinity of DBP for its major ligands. Therefore, free 25(OH)D is strongly correlated to total 25(OH)D in most normal populations. Appropriate studies are needed to define the clinical implications of free rather than total 25(OH)D in normal subjects and in disease states. Special attention is needed for such studies in cases of abnormal DBP concentrations or when one could expect changes in its affinity for its ligands.
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Affiliation(s)
- Daniel Bikle
- VA Medical Center and University of California San Francisco, San Francisco, CA 94158, USA.
| | - Roger Bouillon
- Clinical & Experimental Endocrinology, KULeuven, Herestraat 49 ON1 Box 902, 3000 Leuven, Belgium.
| | - Ravi Thadhani
- Division of Nephrology, Massachusetts General Hospital, Boston, USA.
| | - Inez Schoenmakers
- Medical Research Council (MRC), Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, CB1 9NL Cambridge, UK; Department of Medicine, Faculty of Medicine and Health Sciences, University of East Anglia, NR4 7TJ Norwich, UK.
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15
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Peris P, Filella X, Monegal A, Guañabens N, Foj L, Bonet M, Boquet D, Casado E, Cerdá D, Erra A, Gómez-Vaquero C, Martínez S, Montalá N, Pittarch C, Kanterewicz E, Sala M, Suris X, Carrasco JL. Comparison of total, free and bioavailable 25-OH vitamin D determinations to evaluate its biological activity in healthy adults: the LabOscat study. Osteoporos Int 2017; 28:2457-2464. [PMID: 28466136 DOI: 10.1007/s00198-017-4062-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/17/2017] [Indexed: 01/07/2023]
Abstract
UNLABELLED Determination of different forms of 25-OHD (total, free and bioavailable) in healthy young women does not offer additional advantages over standard 25-OHDT for evaluating vitamin D deficiency. In these subjects 25-OHDT values <15 ng/ml would be more appropriate for defining this deficiency. INTRODUCTION Determination of 25-OH vitamin D serum levels (25-OHD) constitutes the method of choice for evaluating vitamin D deficiency. However, vitamin D-binding protein (DBP) may modulate its bioavailability thereby affecting correct evaluation of 25-OHD status. We analysed the impact of the determination of 25-OHD (total, free and bioavailable) on the evaluation its biologic activity (estimated by serum PTH determination) in healthy young women. METHODS 173 premenopausal women (aged 35-45 yrs.) were included. We analysed serum values of total 25-OHD (25-OHDT), DBP, albumin, PTH and bone formation (PINP,OC) and resorption (NTx,CTx) markers. Free(25-OHDF) and bioavailable (25-OHDB) serum 25-OHD levels were estimated by DBP and albumin determinations and also directly by ELISA (25-OHDF-2). We analysed threshold PTH values for the different forms of 25-OHD and the correlations and differences according to 25-OHDT levels <20 ng/ml. RESULTS 62% of subjects had 25-OHD values <20 ng/ml and also had significantly lower 25-OHDF and 25-OHDB values, with no significant differences in bone markers and PTH values. The PTH threshold value was similar for all forms of 25-OHD (∼70 pg/ml). Women with PTH values >70 had lower 25-OHDT (15.4 ± 1.4 vs. 18.3 ± 2.7, p < 0.05) and 25OHDB values (1.7 ± 0.2 vs. 2.2 ± 0.09, p < 0.05). The different forms of 25OHD were significantly intercorrelated, with marginal correlations between PTH and 25-OHDT (r = -0.136, p = 0.082). CONCLUSIONS Determination of different forms of 25-OHD in healthy young women does not offer additional advantages over standard 25-OHDT for evaluating vitamin D deficiency. In these subjects 25-OHDT values <15 ng/ml would be more appropriate for defining this deficiency.
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Affiliation(s)
- P Peris
- Hospital Clínic de Barcelona, IDIBAPS. CIBERehd, Barcelona, Spain.
| | - X Filella
- Servicio de Bioquímica Clínica, Hospital Clinic, Barcelona, Spain
| | - A Monegal
- Hospital Clínic de Barcelona, IDIBAPS. CIBERehd, Barcelona, Spain
| | - N Guañabens
- Hospital Clínic de Barcelona, IDIBAPS. CIBERehd, Barcelona, Spain
| | - L Foj
- Servicio de Bioquímica Clínica, Hospital Clinic, Barcelona, Spain
| | - M Bonet
- Hospital de l'Alt Penedés, Barcelona, Spain
| | - D Boquet
- Hospital Arnau de Vilanova, Lleida, Spain
| | - E Casado
- Instituto Universitario Parc Taulí, Barcelona, Spain
| | - D Cerdá
- Hospital Moisés Broggi, Barcelona, Spain
| | - A Erra
- Hospital Universitari de Bellvitge, Barcelona, Spain.
| | | | - S Martínez
- Hospital Mútua de Terrassa, Madrid, Spain
| | - N Montalá
- Hospital Sta María, Barcelona, Spain
| | | | | | - M Sala
- Hospital de Figueres, Barcelona, Spain
| | - X Suris
- Hospital de Ganollers, Catalonia, Spain
| | - J L Carrasco
- Departament de Fonaments Clínics, Universitat de Barcelona, Barcelona, Spain
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16
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Chen YH, Lo RY. Alzheimer's disease and osteoporosis. Tzu Chi Med J 2017; 29:138-142. [PMID: 28974906 PMCID: PMC5615992 DOI: 10.4103/tcmj.tcmj_54_17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/13/2017] [Accepted: 03/13/2017] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) and osteoporosis are both common degenerative diseases in the elderly population. The incidence of both diseases increases with age and will be posing enormous societal burden worldwide. It may appear that AD and osteoporosis are two distinct diseases although many risk factors are shared. Previous observational studies have shown that patients with osteoporosis have higher risks of developing AD than those who do not have osteoporosis. Although osteoporosis, falls, and fractures are more often seen in patients with AD than other older adults, the association between these two diseases may be due to a pathophysiological link rather than one condition causing the other. Several in vitro and in vivo studies lend support to this notion. Patients with AD have excessive amyloid plaques in the brain, and the pathology may extend to peripheral organs and cause skeletal amyloid deposition, which would enhance receptor activator nuclear factor-kappa B ligand signaling and lead to greater osteoclast activities. Patients with osteoporosis may have Vitamin D deficiency or lower levels of Vitamin D binding protein, which protects against amyloid aggregation, thus linking Vitamin D deficiency and AD or osteoporosis and AD. Osteoporosis coexisting with AD provides a window to examine the amyloid hypothesis from peripheral tissues. Future studies are warranted to clarify the role of genetic background regarding Vitamin D levels, exposure to sunlight, estrogen replacement therapy, and physical activity in patients with both chronic diseases.
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Affiliation(s)
- Yu-Hung Chen
- Department of Nuclear Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Raymond Y. Lo
- Department of Neurology, Memory and Aging Center, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
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17
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Fat-Soluble Vitamin Deficiency in Pediatric Patients with Biliary Atresia. Gastroenterol Res Pract 2017; 2017:7496860. [PMID: 28690638 PMCID: PMC5485346 DOI: 10.1155/2017/7496860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/07/2017] [Indexed: 02/06/2023] Open
Abstract
Objective To analyze the levels of fat-soluble vitamins (FSVs) in pediatric patients with biliary atresia (BA) before and after the Kasai procedure. Methods Pediatric patients with obstructive jaundice were enrolled in this study. The FSV levels and liver function before, 2 weeks after, and 1, 3, and 6 months after the Kasai procedure were measured. Results FSV deficiency was more obvious in patients with BA than in patients with other cholestatic liver diseases, especially vitamin D deficiency. 25-Hydroxy vitamin D (25-(OH)D) deficiency was more pronounced in younger patients before surgery. The 25-(OH)D level was significantly higher in patients with than without resolution of jaundice 3 months after surgery. At 6 months after surgery, the 25-(OH)D level was abnormally high at 8.76 ng/ml in patients with unresolved jaundice. Conclusions Preoperative FSV deficiency, particularly vitamin D deficiency, is common in patients with BA. 25-(OH)D deficiency is more pronounced in younger children before surgery. Postoperative FSV deficiency was still prevalent as shown by the lower 25-(OH)D levels in patients with BA and unresolved jaundice. This required long-term vitamin AD supplementation for pediatric patients with BA and unresolved jaundice after surgery.
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18
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Wong TH, Gupta ED, Radhakrishnan AK, Gun SC, Chembalingam G, Yeap SS. Effects of 25-hydroxyvitamin D and vitamin D-binding protein on bone mineral density and disease activity in Malaysian patients with rheumatoid arthritis. Int J Rheum Dis 2017; 21:992-1000. [DOI: 10.1111/1756-185x.13048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Tze Hao Wong
- Pathology Division; School of Medicine; International Medical University; Kuala Lumpur Malaysia
| | - Esha Das Gupta
- Internal Medicine Department; School of Medicine; International Medical University; Seremban Malaysia
| | - Ammu K. Radhakrishnan
- Pathology Division; School of Medicine; International Medical University; Kuala Lumpur Malaysia
| | - Suk Chyn Gun
- Internal Medicine Department; Hospital Tuanku Jaafar; Seremban Malaysia
| | | | - Swan Sim Yeap
- Department of Medicine; Subang Jaya Medical Centre; Subang Jaya Malaysia
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19
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Wu L, Gao L, Zhao X, Zhang M, Wu J, Mi J. Associations of Two Obesity-Related Single-Nucleotide Polymorphisms with Adiponectin in Chinese Children. Int J Endocrinol 2017; 2017:6437542. [PMID: 28396685 PMCID: PMC5370521 DOI: 10.1155/2017/6437542] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 01/13/2023] Open
Abstract
Purpose. Genome-wide association studies have found two obesity-related single-nucleotide polymorphisms (SNPs), rs17782313 near the melanocortin-4 receptor (MC4R) gene and rs6265 near the brain-derived neurotrophic factor (BDNF) gene, but the associations of both SNPs with other obesity-related traits are not fully described, especially in children. The aim of the present study is to investigate the associations between the SNPs and adiponectin that has a regulatory role in glucose and lipid metabolism. Methods. We examined the associations of the SNPs with adiponectin in Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. A total of 3503 children participated in the study. Results. The SNP rs6265 was significantly associated with adiponectin under an additive model (P = 0.02 and 0.024, resp.) after adjustment for age, gender, and BMI or obesity statuses. The SNP rs17782313 was significantly associated with low adiponectin under a recessive model. No statistical significance was found between the two SNPs and low adiponectin after correction for multiple testing. Conclusion. We demonstrate for the first time that the SNP rs17782313 near MC4R and the SNP rs6265 near BDNF are associated with adiponectin in Chinese children. These novel findings provide important evidence that adiponectin possibly mediates MC4R and BDNF involved in obesity.
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Affiliation(s)
- Lijun Wu
- Department of Epidemiology, Capital Institute of Pediatrics, Beijing, China
| | - Liwang Gao
- Department of Epidemiology, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoyuan Zhao
- Department of Epidemiology, Capital Institute of Pediatrics, Beijing, China
| | - Meixian Zhang
- Department of Epidemiology, Capital Institute of Pediatrics, Beijing, China
| | - Jianxin Wu
- Department of Biochemistry, Capital Institute of Pediatrics, Beijing, China
| | - Jie Mi
- Department of Epidemiology, Capital Institute of Pediatrics, Beijing, China
- *Jie Mi:
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20
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Mokry LE, Ross S, Morris JA, Manousaki D, Forgetta V, Richards JB. Genetically decreased vitamin D and risk of Alzheimer disease. Neurology 2016; 87:2567-2574. [PMID: 27856775 PMCID: PMC5207000 DOI: 10.1212/wnl.0000000000003430] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/12/2016] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE To test whether genetically decreased vitamin D levels are associated with Alzheimer disease (AD) using mendelian randomization (MR), a method that minimizes bias due to confounding or reverse causation. METHODS We selected single nucleotide polymorphisms (SNPs) that are strongly associated with 25-hydroxyvitamin D (25OHD) levels (p < 5 × 10-8) from the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits (SUNLIGHT) Consortium (N = 33,996) to act as instrumental variables for the MR study. We measured the effect of each of these SNPs on 25OHD levels in the Canadian Multicentre Osteoporosis Study (CaMos; N = 2,347) and obtained the corresponding effect estimates for each SNP on AD risk from the International Genomics of Alzheimer's Project (N = 17,008 AD cases and 37,154 controls). To produce MR estimates, we weighted the effect of each SNP on AD by its effect on 25OHD and meta-analyzed these estimates using a fixed-effects model to provide a summary effect estimate. RESULTS The SUNLIGHT Consortium identified 4 SNPs to be genome-wide significant for 25OHD, which described 2.44% of the variance in 25OHD in CaMos. All 4 SNPs map to genes within the vitamin D metabolic pathway. MR analyses demonstrated that a 1-SD decrease in natural log-transformed 25OHD increased AD risk by 25% (odds ratio 1.25, 95% confidence interval 1.03-1.51, p = 0.021). After sensitivity analysis in which we removed SNPs possibly influenced by pleiotropy and population stratification, the results were largely unchanged. CONCLUSIONS Our results provide evidence supporting 25OHD as a causal risk factor for AD. These findings provide further rationale to understand the effect of vitamin D supplementation on cognition and AD risk in randomized controlled trials.
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Affiliation(s)
- Lauren E Mokry
- From the Department of Epidemiology, Biostatistics and Occupational Health (L.E.M., J.B.R.), Centre for Clinical Epidemiology (L.E.M., S.R., J.A.M., D.M., V.F., J.B.R.), Department of Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Human Genetics (J.A.M., J.B.R.), and Department of Medicine (D.M., J.B.R.), McGill University, Montreal, Quebec, Canada; and Department of Twin Research and Genetic Epidemiology (J.B.R.), King's College London, UK
| | - Stephanie Ross
- From the Department of Epidemiology, Biostatistics and Occupational Health (L.E.M., J.B.R.), Centre for Clinical Epidemiology (L.E.M., S.R., J.A.M., D.M., V.F., J.B.R.), Department of Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Human Genetics (J.A.M., J.B.R.), and Department of Medicine (D.M., J.B.R.), McGill University, Montreal, Quebec, Canada; and Department of Twin Research and Genetic Epidemiology (J.B.R.), King's College London, UK
| | - John A Morris
- From the Department of Epidemiology, Biostatistics and Occupational Health (L.E.M., J.B.R.), Centre for Clinical Epidemiology (L.E.M., S.R., J.A.M., D.M., V.F., J.B.R.), Department of Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Human Genetics (J.A.M., J.B.R.), and Department of Medicine (D.M., J.B.R.), McGill University, Montreal, Quebec, Canada; and Department of Twin Research and Genetic Epidemiology (J.B.R.), King's College London, UK
| | - Despoina Manousaki
- From the Department of Epidemiology, Biostatistics and Occupational Health (L.E.M., J.B.R.), Centre for Clinical Epidemiology (L.E.M., S.R., J.A.M., D.M., V.F., J.B.R.), Department of Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Human Genetics (J.A.M., J.B.R.), and Department of Medicine (D.M., J.B.R.), McGill University, Montreal, Quebec, Canada; and Department of Twin Research and Genetic Epidemiology (J.B.R.), King's College London, UK
| | - Vincenzo Forgetta
- From the Department of Epidemiology, Biostatistics and Occupational Health (L.E.M., J.B.R.), Centre for Clinical Epidemiology (L.E.M., S.R., J.A.M., D.M., V.F., J.B.R.), Department of Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Human Genetics (J.A.M., J.B.R.), and Department of Medicine (D.M., J.B.R.), McGill University, Montreal, Quebec, Canada; and Department of Twin Research and Genetic Epidemiology (J.B.R.), King's College London, UK
| | - J Brent Richards
- From the Department of Epidemiology, Biostatistics and Occupational Health (L.E.M., J.B.R.), Centre for Clinical Epidemiology (L.E.M., S.R., J.A.M., D.M., V.F., J.B.R.), Department of Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Human Genetics (J.A.M., J.B.R.), and Department of Medicine (D.M., J.B.R.), McGill University, Montreal, Quebec, Canada; and Department of Twin Research and Genetic Epidemiology (J.B.R.), King's College London, UK.
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21
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Li SS, Gao LH, Zhang XY, He JW, Fu WZ, Liu YJ, Hu YQ, Zhang ZL. Genetically Low Vitamin D Levels, Bone Mineral Density, and Bone Metabolism Markers: a Mendelian Randomisation Study. Sci Rep 2016; 6:33202. [PMID: 27625044 PMCID: PMC5021966 DOI: 10.1038/srep33202] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 08/22/2016] [Indexed: 01/08/2023] Open
Abstract
Low serum 25-hydroxyvitamin D (25OHD) is associated with osteoporosis and osteoporotic fracture, but it remains uncertain whether these associations are causal. We conducted a Mendelian randomization (MR) study of 1,824 postmenopausal Chinese women to examine whether the detected associations between serum 25OHD and bone mineral density (BMD) and bone metabolism markers were causal. In observational analyses, total serum 25OHD was positively associated with BMD at lumbar spine (P = 0.003), femoral neck (P = 0.006) and total hip (P = 0.005), and was inversely associated with intact parathyroid hormone (PTH) (P = 8.18E-09) and procollagen type 1 N-terminal propeptide (P1NP) (P = 0.020). By contract, the associations of bioavailable and free 25OHD with all tested outcomes were negligible (all
P > 0.05). The use of four single nucleotide polymorphisms, GC-rs2282679, NADSYN1-rs12785878, CYP2R1-rs10741657 and CYP24A1-rs6013897, as candidate instrumental variables in MR analyses showed that none of the two stage least squares models provided evidence for associations between serum 25OHD and either BMD or bone metabolism markers (all P > 0.05). We suggest that after controlling for unidentified confounding factors in MR analyses, the associations between genetically low serum 25OHD and BMD and bone metabolism markers are unlikely to be causal.
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Affiliation(s)
- Shan-Shan Li
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Li-Hong Gao
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Xiao-Ya Zhang
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Jin-We He
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Wen-Zhen Fu
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Yu-Juan Liu
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Yun-Qiu Hu
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
| | - Zhen-Lin Zhang
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.,Shanghai Key Clinical Center for Metabolic Disease, Shanghai 200233, China
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22
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Bouillon R. Free or Total 25OHD as Marker for Vitamin D Status? J Bone Miner Res 2016; 31:1124-7. [PMID: 27172227 DOI: 10.1002/jbmr.2871] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 05/06/2016] [Accepted: 05/09/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Roger Bouillon
- Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
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23
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Altinova AE, Ozkan C, Akturk M, Gulbahar O, Yalcin M, Cakir N, Toruner FB. Vitamin D-binding protein and free vitamin D concentrations in acromegaly. Endocrine 2016; 52:374-9. [PMID: 26547217 DOI: 10.1007/s12020-015-0789-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/26/2015] [Indexed: 12/22/2022]
Abstract
Free 25-hydroxyvitamin D [25(OH)D] is suggested to be important in the determination of vitamin D deficiency, since vitamin D-binding protein (VDBP) may affect total 25(OH)D levels. There are no data about free 25(OH)D concentrations in acromegaly. We aimed to investigate serum VDBP and total and free 25(OH)D levels in patients with acromegaly in comparison with control subjects. We recruited 54 patients with acromegaly and 32 control subjects who were similar according to age, gender, and body mass index. Serum VDBP levels were found to be increased in patients with acromegaly compared to control subjects [90.35 (72.45-111.10) vs. 69.52 (63.89-80.13) mg/l, p = 0.001]. There was statistically no significant difference in serum total 25(OH)D levels between the patients with acromegaly and control subjects [18.63 (13.35-27.73) vs. 22.51 (19.20-28.96) ng/ml, p = 0.05]. Free 25(OH)D levels were significantly decreased in patients with acromegaly compared to control subjects [14.55 (10.45-21.45) vs. 17.75 (15.30-23.75) pg/ml, p = 0.03]. Free 25(OH)D levels correlated positively with total 25(OH)D (p = 0.0001) and HDL cholesterol (p = 0.04) and negatively with fasting blood glucose (p = 0.04). Our findings indicate that VDBP is increased and free 25(OH)D is decreased in acromegaly, while there is no significant alteration in total 25(OH)D.
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Affiliation(s)
- Alev Eroglu Altinova
- Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey
| | - Cigdem Ozkan
- Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey.
| | - Mujde Akturk
- Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey
| | - Ozlem Gulbahar
- Department of Biochemistry, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Muhittin Yalcin
- Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey
| | - Nuri Cakir
- Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey
| | - Fusun Balos Toruner
- Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey
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24
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Mansuri S, Badawi A, Kayaniyil S, Cole DE, Harris SB, Mamakeesick M, Maguire J, Zinman B, Connelly PW, Hanley AJ. Associations of circulating 25(OH)D with cardiometabolic disorders underlying type 2 diabetes mellitus in an Aboriginal Canadian community. Diabetes Res Clin Pract 2015; 109:440-9. [PMID: 25944538 DOI: 10.1016/j.diabres.2015.04.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 02/23/2015] [Accepted: 04/12/2015] [Indexed: 10/23/2022]
Abstract
AIMS To investigate the associations of 25-hydroxyvitamin D (25(OH)D) with insulin resistance (IR), beta-cell function and metabolic syndrome (MetS) in a First Nations population. METHODS We conducted a cross-sectional analysis using data from the Sandy Lake Health and Diabetes Project (2003-2005). A total of 390 participants (>12 y) were assessed for 25(OH)D, fasting glucose, insulin, lipids, blood pressure, inflammatory markers, anthropometric and lifestyle variables and a 75-g oral glucose tolerance test was administered. IR was calculated using the Matsuda insulin sensitivity index (ISOGTT) and the computational homeostasis model assessment of IR (HOMA2-IR). Beta-cell function was calculated using the insulinogenic index (IGI) divided by HOMA-IR (IGI/IR) and the insulin secretion sensitivity index-2 (ISSI-2). The 2009 harmonized criteria were used to define MetS. RESULTS Higher 25(OH)D was associated with a decreased prevalence of dysglycemia (OR = 0.71 95% CI, 0.51-0.97 per SD increase). In addition, there were significant associations of 25(OH)D with measures of insulin action (ISOGTT; beta=0.31; 95% CI, 0.12, 0.49; HOMA2-IR; beta = -29; 95% CI -0.46, -0.11 and beta-cell function (ISSI-2; beta = 0.15; 95% CI, 0.02, 0.28). The prevalence of MetS was 41%. There was a decreased risk (OR=0.73, 95% CI 0.56, 0.94) of MetS per SD increase in baseline 25(OH)D. Finally, there was a significant positive association of 25(OH)D with adiponectin (beta = 0.16; 95% CI = 0.01, 0.31). CONCLUSIONS These results support a potential role for vitamin D metabolism in the natural history of T2DM among Aboriginal Canadians, although carefully designed randomized trials will be required to establish causality.
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Affiliation(s)
- Sudaba Mansuri
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - Alaa Badawi
- Office of Biotechnology, Genomics and Population Health, Public Health Agency of Canada, Toronto, ON, Canada
| | - Sheena Kayaniyil
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - David E Cole
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Stewart B Harris
- Center for Studies in Family Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - Jonathon Maguire
- Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada
| | - Bernard Zinman
- Division of Endocrinology, University of Toronto, Toronto, ON, Canada; Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, ON, Canada; Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Philip W Connelly
- Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada
| | - Anthony J Hanley
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada; Division of Endocrinology, University of Toronto, Toronto, ON, Canada; Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, ON, Canada.
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25
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Pop LC, Shapses SA, Chang B, Sun W, Wang X. VITAMIN D-BINDING PROTEIN IN HEALTHY PRE- AND POSTMENOPAUSAL WOMEN: RELATIONSHIP WITH ESTRADIOL CONCENTRATIONS. Endocr Pract 2015; 21:936-42. [PMID: 26121448 DOI: 10.4158/ep15623.or] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To examine the relationship between endogenous serum estradiol and vitamin D-binding protein (DBP) and total, free, and bioavailable 25-hydroxyvitamin D (25OHD) concentrations in pre- and postmenopausal women. METHODS In 165 healthy women (ages, 26 to 75 years) not taking any form of exogenous estrogen, the serum concentrations of estradiol, 25OHD, DBP, parathyroid hormone, and albumin were measured. Free and bioavailable 25OHD (free + albumin-bound) levels were calculated from total 25OHD, DBP, and serum albumin levels. RESULTS Premenopausal women had higher serum 25OHD (31.5 ± 7.9 ng/mL), DBP (45.3 ± 6.2 mg/dL), and estradiol (52.8 ± 35.0 pg/mL) levels than postmenopausal women (26.5 ± 4.9 ng/mL, 41.7 ± 5.7 mg/dL, and 12.9 ± 4.9 pg/mL), respectively. In addition, the calculated free and bioavailable 25OHD levels were higher in pre- than postmenopausal women (P<.05). Serum estradiol correlated with DBP (r = 0.22; P<.01) and total 25OHD (r = 0.27; P<.01). In multivariate regression models (with or without serum 25OHD), estradiol was independently associated with DBP (P<.05). CONCLUSION Lower estradiol level is one of the factors that contribute to lower DBP levels in older women. Our data indicate that besides well-known factors such as age, gender, and race, serum estradiol concentrations are also a physiologic predictor of DBP concentration.
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26
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Wilson RT, Bortner JD, Roff A, Das A, Battaglioli EJ, Richie JP, Barnholtz-Sloan J, Chinchilli VM, Berg A, Liu G, Salzberg AC, El-Bayoumy K. Genetic and environmental influences on plasma vitamin D binding protein concentrations. Transl Res 2015; 165:667-76. [PMID: 25234352 DOI: 10.1016/j.trsl.2014.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 11/17/2022]
Abstract
Recent studies suggest that low vitamin D-binding protein (VDBP aka group-specific complement or Gc) concentrations may be linked with inflammatory-mediated conditions, including asthma, chronic obstructive pulmonary disease, and cancer. However, these studies may be confounded by substantial racial and ethnic or genetic differences. The purpose of this study was to test the hypothesis that circulating VDBP concentrations are significantly associated with genetic ancestry. We used a validated high-performance liquid chromatography tandem mass spectrometry assay of 25-hydroxyvitamin D3 and its downstream metabolite 24,25-dihydroxyvitamin D3. VDBP concentrations (milligrams per liter) were measured in duplicate using a commercial enzyme-linked immunosorbent assay among healthy African American (n = 56) and Caucasian American (n = 60) participants. Ancestry informative markers across the genome were used to estimate individual genetic ancestry proportions, designed to robustly distinguish between West African and European ancestry. Genotype-defined Gc isoforms were defined using rs7041 and rs4588 combination groups. VDBP concentration was correlated with both Gc isoform (r = 0.93, P < 0.001) and West African genetic ancestry (r = -0.66, P < 0.001). In the final model, Gc isoform, the catabolic ratio of serum vitamin D, oral contraceptive use, and body mass index remained significantly associated with VDBP concentration, after adjustment for genetic ancestry. Failure to adjust for Gc isoform may lead to spurious associations in studies of VDBP concentration and disease risk, particularly when the condition of interest may also be associated with genetic ancestry. The higher circulating VDBP concentrations and higher vitamin D catabolic rate among Caucasian Americans observed here appear to be consistent with lower bone mineral density and racial and ethnic differences in vitamin D-inducing cytokines.
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Affiliation(s)
- Robin Taylor Wilson
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
| | - James D Bortner
- Perelman School of Medicine, University of Pennsylvania Philadelphia, Pennsylvania
| | - Alanna Roff
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Arunangshu Das
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Eric J Battaglioli
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - John P Richie
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jill Barnholtz-Sloan
- Department of Epidemiology and Biostatistics, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, Ohio
| | - Vernon M Chinchilli
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Arthur Berg
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Guodong Liu
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Anna C Salzberg
- Division of Epidemiology, Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Karam El-Bayoumy
- Perelman School of Medicine, University of Pennsylvania Philadelphia, Pennsylvania
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27
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Souberbielle JC. Épidémiologie du déficit en vitamine D. CAHIERS DE NUTRITION ET DE DIÉTÉTIQUE 2014. [DOI: 10.1016/j.cnd.2014.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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28
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Chun RF, Peercy BE, Orwoll ES, Nielson CM, Adams JS, Hewison M. Vitamin D and DBP: the free hormone hypothesis revisited. J Steroid Biochem Mol Biol 2014; 144 Pt A:132-7. [PMID: 24095930 PMCID: PMC3976473 DOI: 10.1016/j.jsbmb.2013.09.012] [Citation(s) in RCA: 302] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/20/2013] [Accepted: 09/24/2013] [Indexed: 12/21/2022]
Abstract
The last five years have witnessed a remarkable renaissance in vitamin D research and a complete re-evaluation of its benefits to human health. Two key factors have catalyzed these changes. First, it now seems likely that localized, tissue-specific, conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)2D) drives many of the newly recognized effects of vitamin D on human health. The second key factor concerns the ongoing discussion as to what constitutes adequate or optimal serum vitamin D (25OHD) status, with the possibility that vitamin D-deficiency is common to communities across the globe. These two concepts appear to be directly linked when low serum concentrations of 25OHD compromise intracrine generation of 1,25(OH)2D within target tissues. But, is this an over-simplification? Pro-hormone 25OHD is a lipophilic molecule that is transported in the circulation bound primarily to vitamin D binding protein (DBP). While the association between 25OHD and DBP is pivotal for renal handling of 25OHD and endocrine synthesis of 1,25(OH)2D, what is the role of DBP for extra-renal synthesis of 1,25(OH)2D? We hypothesize that binding to DBP impairs delivery of 25OHD to the vitamin D-activating enzyme 1α-hydroxylase in some target cells. Specifically, it is unbound, 'free' 25OHD that drives many of the non-classical actions of vitamin D. Levels of 'free' 25OHD are dependent on the concentration of DBP and alternative serum binding proteins such as albumin, but will also be influenced by variations in DBP binding affinity for specific vitamin D metabolites. The aim of this review will be to discuss the merits of 'free 25OHD' as an alternative marker of vitamin D status, particularly in the context of non-classical responses to vitamin D. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
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Affiliation(s)
- Rene F Chun
- Orthopaedic Hospital Research Center, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Bradford E Peercy
- Department of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Eric S Orwoll
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR 97201, USA
| | - Carrie M Nielson
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR 97201, USA
| | - John S Adams
- Orthopaedic Hospital Research Center, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Martin Hewison
- Orthopaedic Hospital Research Center, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA.
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29
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The causal effect of vitamin D binding protein (DBP) levels on calcemic and cardiometabolic diseases: a Mendelian randomization study. PLoS Med 2014; 11:e1001751. [PMID: 25350643 PMCID: PMC4211663 DOI: 10.1371/journal.pmed.1001751] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 09/19/2014] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Observational studies have shown that vitamin D binding protein (DBP) levels, a key determinant of 25-hydroxy-vitamin D (25OHD) levels, and 25OHD levels themselves both associate with risk of disease. If 25OHD levels have a causal influence on disease, and DBP lies in this causal pathway, then DBP levels should likewise be causally associated with disease. We undertook a Mendelian randomization study to determine whether DBP levels have causal effects on common calcemic and cardiometabolic disease. METHODS AND FINDINGS We measured DBP and 25OHD levels in 2,254 individuals, followed for up to 10 y, in the Canadian Multicentre Osteoporosis Study (CaMos). Using the single nucleotide polymorphism rs2282679 as an instrumental variable, we applied Mendelian randomization methods to determine the causal effect of DBP on calcemic (osteoporosis and hyperparathyroidism) and cardiometabolic diseases (hypertension, type 2 diabetes, coronary artery disease, and stroke) and related traits, first in CaMos and then in large-scale genome-wide association study consortia. The effect allele was associated with an age- and sex-adjusted decrease in DBP level of 27.4 mg/l (95% CI 24.7, 30.0; n = 2,254). DBP had a strong observational and causal association with 25OHD levels (p = 3.2 × 10(-19)). While DBP levels were observationally associated with calcium and body mass index (BMI), these associations were not supported by causal analyses. Despite well-powered sample sizes from consortia, there were no associations of rs2282679 with any other traits and diseases: fasting glucose (0.00 mmol/l [95% CI -0.01, 0.01]; p = 1.00; n = 46,186); fasting insulin (0.01 pmol/l [95% CI -0.00, 0.01,]; p = 0.22; n = 46,186); BMI (0.00 kg/m(2) [95% CI -0.01, 0.01]; p = 0.80; n = 127,587); bone mineral density (0.01 g/cm(2) [95% CI -0.01, 0.03]; p = 0.36; n = 32,961); mean arterial pressure (-0.06 mm Hg [95% CI -0.19, 0.07]); p = 0.36; n = 28,775); ischemic stroke (odds ratio [OR] = 1.00 [95% CI 0.97, 1.04]; p = 0.92; n = 12,389/62,004 cases/controls); coronary artery disease (OR = 1.02 [95% CI 0.99, 1.05]; p = 0.31; n = 22,233/64,762); or type 2 diabetes (OR = 1.01 [95% CI 0.97, 1.05]; p = 0.76; n = 9,580/53,810). CONCLUSIONS DBP has no demonstrable causal effect on any of the diseases or traits investigated here, except 25OHD levels. It remains to be determined whether 25OHD has a causal effect on these outcomes independent of DBP. Please see later in the article for the Editors' Summary.
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30
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Schwartz JB, Lai J, Lizaola B, Kane L, Markova S, Weyland P, Terrault NA, Stotland N, Bikle D. A comparison of measured and calculated free 25(OH) vitamin D levels in clinical populations. J Clin Endocrinol Metab 2014; 99:1631-7. [PMID: 24483159 PMCID: PMC4010704 DOI: 10.1210/jc.2013-3874] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Our goal was to compare direct quantitation of circulating free 25-hydroxyvitamin D (25(OH)D)levels to calculated free 25(OH)D levels and their relationships to intact PTH (iPTH), a biomarker of 25(OH)D effect, in humans with a range of clinical conditions. PATIENTS AND METHODS Serum samples and clinical data were collected from 155 people: 111 without cirrhosis or pregnancy (comparison group), 24 cirrhotic patients with albumin <2.9 g/dL, and 20 pregnant women (second and third trimester). Total 25(OH)D (LC/MS/MS), free 25(OH)D (immunoassay), vitamin D binding protein (DBP) (immunoassay), albumin, and iPTH (immunoassay) were measured. RESULTS Total 25(OH)D, DBP, and albumin were lowest in patients with cirrhosis, but measured free 25(OH)D was highest in this group (P < .001). DBP was highest in pregnant women (P < .001), but measured free 25(OH)D did not differ from the comparison group. Calculated free 25(OH)D was positively correlated with measured free 25(OH)D (P < .0001) but explained only 13% of the variability with calculated values higher than measured. African Americans had lower DBP than other ethnic populations within all clinical groups (P < .03), and differences between measured and calculated free 25(OH)D were greatest in African Americans (P < .001). Measured free 25(OH)D was correlated with total 25(OH)D (P < .0001; r(2) = 0.51), but calculated free 25(OH)D was not. Similarly, both measured free 25(OH)D (P < .02) and total 25(OH)D (P < .05) were correlated with iPTH, but calculated free 25(OH)D was not. CONCLUSIONS Calculated free 25(OH)D levels varied considerably from direct measurements of free 25(OH)D with discrepancies greatest in the data for African Americans. Differences in DBP binding affinity likely contributed to estimation errors between the races. Directly measured free 25(OH)D concentrations were related to iPTH, but calculated estimates were not. Current algorithms to calculate free 25(OH)D may not be accurate. Further evaluation of directly measured free 25(OH)D levels to determine its role in research and clinical management of patients is needed.
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Affiliation(s)
- J B Schwartz
- Departments of Medicine (J.B.S., J.L., B.L., N.A.T., D.B.), Bioengineering and Therapeutic Sciences (J.B.S., S.M.), Physiological Nursing (P.W.), Obstetrics and Gynecology (N.S.), and Dermatology (D.B.), University of California San Francisco, San Francisco, California 94143; and Jewish Home of San Francisco (J.B.S., L.K.), San Francisco, California 94112
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Yousefzadeh P, Shapses SA, Wang X. Vitamin D Binding Protein Impact on 25-Hydroxyvitamin D Levels under Different Physiologic and Pathologic Conditions. Int J Endocrinol 2014; 2014:981581. [PMID: 24868205 PMCID: PMC4020458 DOI: 10.1155/2014/981581] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 04/03/2014] [Accepted: 04/10/2014] [Indexed: 12/15/2022] Open
Abstract
There is a high prevalence of vitamin D deficiency worldwide, but how to define vitamin D deficiency is controversial. Currently, the plasma concentration of total 25-hydroxyvitamin D [25(OH)D] is considered an indicator of vitamin D status. The free hormone hypothesis states that protein-bound hormones are inactive while unbound hormones are free to exert biological activity. The majority of circulating 25(OH)D and 1,25(OH)2D is tightly bound to vitamin D binding protein (DBP), 10-15% is bound to albumin, and less than 1% of circulating vitamin D exists in an unbound form. While DBP is relatively stable in most healthy populations, a recent study showed that there are gene polymorphisms associated with race and ethnicity that could alter DBP levels and binding affinity. Furthermore, in some clinical situations, total vitamin D levels are altered and knowing whether DBP is also altered may have treatment implications. The aim of this review is to assess DBP concentration in different physiological and pathophysiological conditions. We suggest that DBP should be considered in the interpretation of 25(OH)D levels.
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Affiliation(s)
- Pegah Yousefzadeh
- Division of Endocrinology, Metabolism & Nutrition, Department of Medicine, Rutgers University-Robert Wood Johnson Medical School, New Brunswick, NJ 08903, USA
| | - Sue A. Shapses
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - Xiangbing Wang
- Division of Endocrinology, Metabolism & Nutrition, Department of Medicine, Rutgers University-Robert Wood Johnson Medical School, New Brunswick, NJ 08903, USA
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Salamon A, Hepp B, Mátrai A, Biró C, Agota K, Fata E, Lőcsei Z, Toldy E. [Vitamin D supply of patients with hip fracture]. Orv Hetil 2014; 155:659-68. [PMID: 24755448 DOI: 10.1556/oh.2014.29878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Vitamin D deficiency is an important risk factor for fractures. However, there are few data available only on the relationship between serum 25-hydroxyvitamin D levels and recovery after surgery for hip fracture. AIM The authors investigate the vitamin D supply of patients with hip fractures. METHOD Between February and September 2013, serum 25-hydroxyvitamin D and parathyroid hormone levels were determined in 203 patients with hip fracture (74.8±11.5 ys; 67 men and 136 women) and in 74 control subjects. RESULTS Vitamin D deficiency and secondary hyperparathyroidism occurred significantly more frequently in patients with hip fracture than in control subjects (72% vs. 45%, and 33% vs. 17%, respectively). Patients with better condition after surgery showed higher 25-hydroxyvitamin D levels (p<0.001) than those with poor condition. Serum 25-hydroxyvitamin D were lower in the 31 patients who died [median of survival time: 19 (5-52) days] compared to those who survived [22.6 (9.5-45.0) vs. 33.0 (16.5-56.6) nmol/l]. CONCLUSIONS The association between vitamin-D deficiency and mortality as well as the positive correlation between serum 25-hydroxyvitamin D levels and better postoperative condition confirm the importance of proper vitamin D supply in the prevention and cure of hip fractures, what is more in the increase of the chance of survival.
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Affiliation(s)
- Antal Salamon
- Markusovszky Egyetemi Oktatókórház Baleseti Sebészeti Osztály Szombathely
| | - Balázs Hepp
- Markusovszky Egyetemi Oktatókórház Baleseti Sebészeti Osztály Szombathely
| | - Akos Mátrai
- Markusovszky Egyetemi Oktatókórház Baleseti Sebészeti Osztály Szombathely
| | - Csaba Biró
- Markusovszky Egyetemi Oktatókórház Baleseti Sebészeti Osztály Szombathely
| | - Katalin Agota
- Markusovszky Egyetemi Oktatókórház Általános Belgyógyászati Osztály Szombathely
| | - Emőke Fata
- Markusovszky Egyetemi Oktatókórház Általános Belgyógyászati Osztály Szombathely
| | - Zoltán Lőcsei
- Markusovszky Egyetemi Oktatókórház Általános Belgyógyászati Osztály Szombathely
| | - Erzsébet Toldy
- Markusovszky Egyetemi Oktatókórház Központi Laboratórium Szombathely Király u. 11. II/10. 9700 Pécsi Tudományegyetem, Egészségtudományi Kar Diagnosztikai Intézet Pécs
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Alfawaz H, Tamim H, Alharbi S, Aljaser S, Tamimi W. Vitamin D status among patients visiting a tertiary care center in Riyadh, Saudi Arabia: a retrospective review of 3475 cases. BMC Public Health 2014; 14:159. [PMID: 24524260 PMCID: PMC3942273 DOI: 10.1186/1471-2458-14-159] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 02/05/2014] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Vitamin D deficiency has been implicated in several chronic, non-communicable diseases independent of its conventional role in bone and calcium homeostasis. In this retrospective study, we determined the prevalence of vitamin D deficiency and its association to several cardiometabolic indices among patients visiting King Abdulaziz Medical City (KAMC), a tertiary hospital in Riyadh, Saudi Arabia. METHODS A total of 3475 charts of out-patient subjects who visited KAMC from September 2009 until December 2010 were reviewed and included. Variables of interest included measurements of vitamin D status, glycemic and renal profile, as well as trace elements (calcium and phosphorous). RESULTS The over-all prevalence of vitamin D deficiency in the cohort studied was 78.1% in females and 72.4% in males. 25(OH) vitamin D was significantly associated with increasing age and weight (p-values < 0.0001 and 0.005, respectively). It was also positively associated with albumin, calcium and phosphorous (p-values < 0.0001, < 0.0001 and 0.0007, respectively) and negatively associated with alkaline phosphatase as well as circulating levels of PTH (p-values 0.0002 and 0.0007, respectively). CONCLUSION In conclusion, vitamin D deficiency is overwhelmingly common among patients seen at KAMC regardless of the medical condition, and it is significantly associated with increasing age, weight and markers of calcium homeostasis. Findings of the present study further stress the spotlight on vitamin D deficiency epidemic in the country and region in general.
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Affiliation(s)
- Hanan Alfawaz
- Department of Food Science and Nutrition, College of Food Science and Agriculture King Saud University, P, O, Box 22452, Riyadh 11495, Saudi Arabia.
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Johnsen MS, Grimnes G, Figenschau Y, Torjesen PA, Almås B, Jorde R. Serum free and bio-available 25-hydroxyvitamin D correlate better with bone density than serum total 25-hydroxyvitamin D. Scand J Clin Lab Invest 2014; 74:177-83. [PMID: 24383929 DOI: 10.3109/00365513.2013.869701] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In the circulation 25-hydroxyvitamin D (25(OH)D) is bound to vitamin D-binding protein (DBP) and albumin. Only a small fraction is in the unbound, free form. According to the 'free-hormone-hypothesis' only the free form is biologically active. Genetic differences in DBP may affect the binding to 25(OH)D and thereby the amount of free 25(OH)D. In the present study sera were obtained from 265 postmenopausal women with low bone mass density (BMD). Serum 25(OH)D, DBP and albumin were measured and the free and bio-available (free + albumin-bound) 25(OH)D calculated. Based on genotyping of the polymorphisms rs7041 and rs4588, the six common DBP phenotypes were identified and the free and bio-available 25(OH)D calculated according to the corresponding binding coefficients. Relations between measures of 25(OH)D and PTH and BMD were evaluated with linear regression adjusted for age and BMI. The calculated amount of free and bio-available 25(OH)D was 0.03% and 13.1%, respectively, of the measured total serum 25(OH)D. Adjusting for DBP phenotype affected the calculated free and bio-available 25(OH)D levels up to 37.5%. All measures of 25(OH)D correlated significantly with PTH, whereas a significant association with BMD was only seen for the free and bio-available 25(OH)D measures. Adjusting for the DBP phenotypes improved the associations. These relations were almost exclusively seen in subjects not using vitamin D and/or calcium supplements. In conclusion, the free and bio-available forms of 25(OH)D may be a more informative measure of vitamin D status than total 25(OH)D. Adjustment for DBP phenotype may improve this further.
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Affiliation(s)
- Martin S Johnsen
- Tromsø Endocrine Research Group, Department of Clinical Medicine, University of Tromsø , Tromsø
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