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Stevens CM, Jain SK. Vitamin D/Bone Mineral Density and Triglyceride Paradoxes Seen in African Americans: A Cross-Sectional Study and Review of the Literature. Int J Mol Sci 2024; 25:1305. [PMID: 38279305 PMCID: PMC10816015 DOI: 10.3390/ijms25021305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 01/28/2024] Open
Abstract
Vitamin D is known to have a positive effect on bone health. Despite the greater frequency of vitamin D deficiency in African Americans (AA), they have a higher bone mineral density (BMD) compared to whites, demonstrating a disconnect between BMD and vitamin D levels in AA. Another intriguing relationship seen in AA is the triglyceride (TG) paradox, an unusual phenomenon in which a normal TG status is observed even when patients house conditions known to be characterized by high TG levels, such as Type II diabetes. To the best of our knowledge, no study has examined whether these two paradoxical relationships exist simultaneously in AA subjects with Type II diabetes. In this study, we compared levels of blood markers, including HbA1c, TG, and vitamin D, measured as serum 25-hydroxyvitamin D [25(OH)VD] µM/mL, [25(OH)VD]/TG, calcium, and BMD in AA (n = 56) and white (n = 26) subjects with Type II diabetes to see whether these relationships exist concurrently. We found that AA subjects had significantly lower TG and [25(OH)VD] levels and a significantly higher BMD status compared to white subjects, even when the ages, BMI, duration of diabetes, HbA1c, and calcium levels were similar between the two groups. This demonstrates that these two paradoxical relationships exist simultaneously in Type II diabetic AA subjects. In addition to these findings, we discuss the current hypotheses in the literature that attempt to explain why these two intriguing relationships exist. This review also discusses four novel hypotheses, such as altered circulating levels and the potential role of estrogen and hydrogen sulfide on BMD and HMG-CoA reductase as a possible contributor to the TG paradox in AA subjects. This manuscript demonstrates that there are still many unanswered questions regarding these two paradoxical relationships and further research is needed to determine why they exist and how they can be implemented to improve healthcare.
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Affiliation(s)
- Christopher M Stevens
- Department of Pediatrics, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71103, USA
| | - Sushil K Jain
- Department of Pediatrics, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71103, USA
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2
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Suzuki K, Tsujiguchi H, Hara A, Miyagi S, Nguyen TTT, Kambayashi Y, Shimizu Y, Suzuki F, Takazawa C, Nakamura M, Tsuboi H, Kannon T, Tajima A, Nakamura H. Bone Strength of the Calcaneus Is Associated with Dietary Calcium Intake in Older Japanese Men, but Not Women. Nutrients 2022; 14:nu14245225. [PMID: 36558384 PMCID: PMC9781445 DOI: 10.3390/nu14245225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
The relationship between calcium intake and bone strength in older Asian individuals, including Japanese, is controversial; therefore, we herein investigated this relationship in older Japanese populations. We performed a cross-sectional analysis of 314 participants older than 65 years who voluntarily participated in a medical examination and responded to questionnaires. The osteo-sono assessment index (OSI) measured at the right calcaneus using a quantitative ultrasonic device was used as an indicator of bone strength. The daily dietary intake of calcium was assessed using a brief-type self-administered diet history questionnaire. A two-way analysis of covariance revealed a significant interaction between sex and calcium intake on the OSI (p < 0.01). A multiple regression analysis showed a positive correlation between calcium intake and the OSI in males (p < 0.01), but not females (p = 0.27). In females, grip strength divided by body weight positively correlated with the OSI (p = 0.04). The present results suggest that a higher calcium intake contributes to bone strength in older Japanese males. Although a higher grip strength may contribute to bone strength in females, the potential of estrogen as a confounding factor needs to be considered.
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Affiliation(s)
- Keita Suzuki
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Correspondence: ; Tel.: +81-76-265-2218
| | - Hiromasa Tsujiguchi
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Department of Public Health, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Kanazawa University Advanced Preventive Medical Sciences Research Center, Kanazawa 920-8640, Ishikawa, Japan
| | - Akinori Hara
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Department of Public Health, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Kanazawa University Advanced Preventive Medical Sciences Research Center, Kanazawa 920-8640, Ishikawa, Japan
| | - Sakae Miyagi
- Kanazawa University Advanced Preventive Medical Sciences Research Center, Kanazawa 920-8640, Ishikawa, Japan
- Innovative Clinical Research Center, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
| | - Thao Thi Thu Nguyen
- Department of Epidemiology, Faculty of Public Health, Haiphong University of Medicine and Pharmacy, Hai Phong 04000-05000, Vietnam
| | - Yasuhiro Kambayashi
- Department of Public Health, Faculty of Veterinary Medicine, Okayama University of Science, Imabari 794-0085, Ehime, Japan
| | - Yukari Shimizu
- Department of Nursing, Faculty of Health Sciences, Komatsu University, Komatsu 923-8511, Ishikawa, Japan
| | - Fumihiko Suzuki
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Community Medicine Support Dentistry, Ohu University Hospital, Koriyama 963-8611, Fukushima, Japan
| | - Chie Takazawa
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
| | - Masaharu Nakamura
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
| | - Hirohito Tsuboi
- Graduate School of Human Nursing, The University of Shiga Prefecture, Hikone 522-8533, Shiga, Japan
| | - Takayuki Kannon
- Department of Biomedical Data Science, School of Medicine, Fujita Health University, Toyoake 470-1101, Aichi, Japan
| | - Atsushi Tajima
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
| | - Hiroyuki Nakamura
- Department of Hygiene and Public Health, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Department of Public Health, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa 920-8640, Ishikawa, Japan
- Kanazawa University Advanced Preventive Medical Sciences Research Center, Kanazawa 920-8640, Ishikawa, Japan
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3
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Kong R, Laskin OL, Kaushik D, Jin F, Ma J, McIntosh J, Souza M, Almstead N. Ataluren Pharmacokinetics in Healthy Japanese and Caucasian Subjects. Clin Pharmacol Drug Dev 2019; 8:172-178. [PMID: 30629861 PMCID: PMC6590116 DOI: 10.1002/cpdd.645] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/03/2018] [Indexed: 12/11/2022]
Abstract
To evaluate the potential for ethnicity-related differences in ataluren pharmacokinetics (PK) and safety, a phase 1 single-dose study was conducted in 48 healthy (24 Japanese and 24 Caucasian subjects), nonsmoking male volunteers who were equally divided into 3 cohorts of oral doses at 5, 10, and 20 mg/kg. Blood samples were collected until 48 hours postdose. PK results demonstrated rapid absorption of ataluren, with peak plasma levels (Cmax ) being attained between 0.875 and 2.5 hours after dosing. The mean Cmax and area under the concentration-time curve (AUC(0-last) ) increased with each increasing dose level in both Japanese and Caucasian subjects. Although the Cmax was similar across all subjects at each dose regardless of ethnicity, Japanese subjects had a mean AUC(0-last) approximately 14% to 34% lower than that of Caucasian subjects across the 3 dose levels. This difference was likely due to the higher variability of AUC values in Caucasian subjects and the relatively small study population. In conclusion, similar ataluren PK profiles were observed in healthy Japanese and Caucasian subjects following single oral administration of ataluren at all dose levels.
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Affiliation(s)
- Ronald Kong
- PTC Therapeutics, Inc, South Plainfield, NJ, USA
| | - Oscar L Laskin
- PTC Therapeutics, Inc, South Plainfield, NJ, USA.,R2D Pharma Services LLC, Princeton, NJ, USA
| | | | - Fengbin Jin
- PTC Therapeutics, Inc, South Plainfield, NJ, USA
| | - Jiyuan Ma
- PTC Therapeutics, Inc, South Plainfield, NJ, USA
| | | | - Marcio Souza
- PTC Therapeutics, Inc, South Plainfield, NJ, USA
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4
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Li Y, Liu L, Gomez D, Chen J, Tong Z, Palmisano M, Zhou S. Pharmacokinetics and safety of Enasidenib following single oral doses in Japanese and Caucasian subjects. Pharmacol Res Perspect 2018; 6:e00436. [PMID: 30386625 PMCID: PMC6199364 DOI: 10.1002/prp2.436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/31/2018] [Accepted: 09/20/2018] [Indexed: 12/22/2022] Open
Abstract
The aim of this study was to assess and compare the pharmacokinetics (PK) and safety of Enasidenib in healthy adult male Japanese subjects to healthy adult male Caucasian subjects. This was a phase 1, single dose study to evaluate the PK and safety of Enasidenib in healthy adult male Japanese subjects relative to healthy adult male Caucasian subjects. A total of 62 subjects (31 Japanese and 31 Caucasian) were enrolled into three dose cohorts (single doses of 50 mg, 100 mg, or 300 mg Enasidenib). Blood samples for PK assessment were collected up to 672 hours postdose. Safety was evaluated throughout the study. In the present study, we found that PK exposures of Enasidenib and its metabolite AGI-16903 for Caucasian and Japanese subjects were comparable at the 50, 100, and 300 mg dose levels, demonstrated by that the 90% confidence intervals (CIs) of geometric mean ratios for AUCs and Cmax between these two populations generally contained 100% from all three treatment cohorts. In conclusion, PK exposures of Enasidenib and its metabolite AGI-16903 for Caucasians and Japanese subjects were comparable and Enasidenib was safe and well tolerated with no apparent differences between Japanese and Caucasian subjects when administered as single oral doses of 50 mg, 100 mg, and 300 mg.
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Affiliation(s)
- Yan Li
- Translational Development and Clinical PharmacologyCelgene CorporationSummitNew Jersey
| | - Liangang Liu
- BiostatisticsCelgene CorporationSummitNew Jersey
| | - Diana Gomez
- Translational Development and Clinical PharmacologyCelgene CorporationSummitNew Jersey
| | - Jian Chen
- Non‐Clinical DevelopmentCelgene CorporationSummitNew Jersey
| | - Zeen Tong
- Non‐Clinical DevelopmentCelgene CorporationSummitNew Jersey
| | - Maria Palmisano
- Translational Development and Clinical PharmacologyCelgene CorporationSummitNew Jersey
| | - Simon Zhou
- Translational Development and Clinical PharmacologyCelgene CorporationSummitNew Jersey
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5
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Lee WTK, Jiang J, Hu P, Hu X, Roberts DCK, Cheng JCY. Use of Stable Calcium Isotopes (42Ca & 44Ca) in Evaluation of Calcium Absorption in Beijing Adolescents with Low Vitamin D Status. Food Nutr Bull 2018. [DOI: 10.1177/15648265020233s108] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Female adolescent populations with low calcium intakes and sub-optimal vitamin D status are found in northern China. Whether these individuals are able to adapt by enhancing calcium absorption and reducing calcium excretion for maximizing calcium retention is unknown. This study examined the association between true-fractional-calcium-absorption (TFCA), plasma 25-hydroxyvitamin-D, and urinary calcium excretion among adolescents in Northern China. Twelve healthy girls 9 to 17 years old were recruited from Beijing during a winter. Calcium intake, anthropometry, pubertal status, plasma 25-hydroxyvitamin-Ds (25-OHD), serum calcium, and urinary calcium were determined. TFCA was evaluated by dual stable calcium isotopes. The mean ± SD calcium intake, 24-hour urinary calcium excretion, plasma 25-OHD and TFCA were 591 ± 164 mg/day, 79.9 ± 49.6 mg/day, 30.5 ± 9.8 nmol/L, and 60.4 ± 14.4%, respectively. TFCA was inversely correlated with 25-OHD (r = −0.73, p = .008). Urinary calcium was correlated with the onset of menarche (r = 0.63, p = .027). Post-menarcheal girls had a higher urinary calcium output than premenarcheal girls (p = .03). Adolescents from north China with sub-optimal vitamin-D status are able to adapt by enhancing TFCA and reducing urinary calcium excretion to retain calcium for bone development. TFCA was inversely correlated with plasma 25-OHD. Whether a higher efficiency of calcium absorption is sustainable if the shortfall of vitamin D persisting remains to be studied.
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Affiliation(s)
- Warren Tak Keung Lee
- Department of Orthopaedics & Traumatology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong
| | - Ji Jiang
- Clinical Pharmacological Research Center Laboratory, Peking Union Medical College Hospital, Beijing, China
| | - Pei Hu
- Clinical Pharmacological Research Center Laboratory, Peking Union Medical College Hospital, Beijing, China
| | - Xiaopeng Hu
- Clinical Pharmacological Research Center Laboratory, Peking Union Medical College Hospital, Beijing, China
| | - David Charles Keith Roberts
- Discipline of Nutrition & Dietetics, School of Health Sciences, Faculty of Medicine & Health Sciences, The University of Newcastle, Australia
| | - Jack Chun Yiu Cheng
- Department of Orthopaedics & Traumatology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong
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6
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Aloia J, Fazzari M, Islam S, Mikhail M, Shieh A, Katumuluwa S, Dhaliwal R, Stolberg A, Usera G, Ragolia L. Vitamin D Supplementation in Elderly Black Women Does Not Prevent Bone Loss: A Randomized Controlled Trial. J Bone Miner Res 2018; 33:1916-1922. [PMID: 29905969 DOI: 10.1002/jbmr.3521] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/21/2018] [Accepted: 06/06/2018] [Indexed: 01/12/2023]
Abstract
Black Americans have lower levels of serum 25(OH)D but superior bone health compared to white Americans. There is controversy over whether they should be screened for vitamin D deficiency and have higher vitamin D requirements than recommended by the Institute of Medicine (IOM). The purpose of this trial was to determine whether Vitamin D supplementation in elderly black women prevents bone loss. A total of 260 healthy black American women, 60 years of age and older were recruited to take part in a two-arm, double-dummy 3-year randomized controlled trial (RCT) of vitamin D3 versus placebo. The study was conducted in an ambulatory clinical research center. Vitamin D3 dose was adjusted to maintain serum 25(OH)D above 75 nmol/L. Bone mineral density (BMD) and serum were measured for parathyroid hormone (PTH), C-terminal crosslink telopeptide (CTX), and bone-specific alkaline phosphatase (BSAP) every 6 months. Baseline serum 25(OH)D3 was 54.8 ± 16.8 nmol/L. There was no group × time interaction effect for any BMD measurement. For all BMD measurements, except for total body and spine, there was a statistically significant negative effect of time (p < 0.001). An equivalency analysis showed that the treatment group was equivalent to the control group. Serum PTH and BSAP declined, with a greater decline of PTH in the treatment group. The rate of bone loss with serum 25(OH)D above 75 nmol/L is comparable to the rate of loss with serum 25(OH)D at the Recommended Dietary Allowance (RDA) of 50 nmol/L. Black Americans should have the same exposure to vitamin D as white Americans. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- John Aloia
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Melissa Fazzari
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Shahidul Islam
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Mageda Mikhail
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Albert Shieh
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Subhashini Katumuluwa
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Ruban Dhaliwal
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Alexandra Stolberg
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Gianina Usera
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
| | - Louis Ragolia
- Bone Mineral Research Center, New York University (NYU) Winthrop Hospital, Mineola, NY, USA
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7
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O'Brien KO, Abrams SA. Using stable isotope tracers to study bone metabolism in children. J Physiol 2018; 597:1311-1319. [PMID: 29869788 DOI: 10.1113/jp275452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/08/2018] [Indexed: 11/08/2022] Open
Abstract
Skeletal mineralization is initiated in utero and continues throughout childhood and adolescence. During these key periods of the life cycle, calcium retention must increase significantly to provide sufficient mineral for bone deposition and skeletal growth. Stable calcium isotopes have served as a fundamental tool to non-invasively characterize the dynamic changes in calcium physiology that occur from infancy through adolescence. These approaches have helped define the dynamics of calcium absorption and utilization in healthy children and in children with chronic diseases. As data in this area have accumulated, new areas of emphasis are beginning to characterize the determinants of variability in mineral retention, the genetic determinants of bone turnover and calcium flux and the impact of the gut microbiome on whole body and niche specific calcium dynamics. Advances in these areas will help define calcium utilization in paediatric populations and provide information that may be useful in maximizing bone acquisition across this critical phase of the life cycle.
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Affiliation(s)
| | - Steven A Abrams
- Department of Pediatrics, Dell Medical School at the University of Texas at Austin, Austin, TX, 78723, USA
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8
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Cao F, Lu L, Abrams SA, Hawthorne KM, Tam A, Jin W, Dawson B, Shypailo R, Liu H, Lee B, Nagamani SCS, Wang LL. Generalized metabolic bone disease and fracture risk in Rothmund-Thomson syndrome. Hum Mol Genet 2018; 26:3046-3055. [PMID: 28486640 DOI: 10.1093/hmg/ddx178] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 05/03/2017] [Indexed: 01/05/2023] Open
Abstract
Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder characterized by poikiloderma, small stature, sparse hair, skeletal abnormalities, increased risk of osteosarcoma, and decreased bone mass. To date, there has not been a comprehensive evaluation of the prevalence and extent of metabolic bone disease in RTS. Furthermore, the mechanisms that result in this phenotype are largely unknown. In this report, we provide a detailed evaluation of 29 individuals with RTS with respect to their metabolic bone status including bone mineral density, calcium kinetics studies, and markers of bone remodeling. We show that individuals with RTS have decreased areal bone mineral density. Additionally, we demonstrate that the presence of pathogenic variants in RECQL4 and low bone mineral density correlate with the history of increased risk of fractures. Using a RECQL4-deficient mouse model that recapitulates skeletal abnormalities seen in individuals with RTS, we demonstrate that generalized skeletal involvement is likely due to decreased osteogenesis. Our findings are clinically relevant as they may help in the risk stratification of patients with RTS and also in the identification of individuals who may benefit from additional surveillance and management of metabolic bone disease.
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Affiliation(s)
- Felicia Cao
- Interdepartmental Program in Translational Biology and Molecular Medicine.,Medical Scientist Training Program
| | - Linchao Lu
- Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Steven A Abrams
- Department of Pediatrics, Dell Medical School at the University of Texas at Austin, Austin, TX 78712, USA
| | - Keli M Hawthorne
- Department of Pediatrics, Dell Medical School at the University of Texas at Austin, Austin, TX 78712, USA
| | | | - Weidong Jin
- Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Roman Shypailo
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics
| | - Hao Liu
- Division of Biostatistics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | | | - Sandesh C S Nagamani
- Department of Molecular and Human Genetics.,Texas Children's Hospital, Houston, TX 77030, USA
| | - Lisa L Wang
- Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, Houston, TX 77030, USA.,Texas Children's Hospital, Houston, TX 77030, USA
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9
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Ethnic disparities in the dietary requirement for vitamin D during pregnancy: considerations for nutrition policy and research. Proc Nutr Soc 2017; 77:164-173. [PMID: 29182508 DOI: 10.1017/s0029665117004116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite the inverse association between skin colour and efficiency of cutaneous vitamin D synthesis, in addition to the widely accepted racial disparity in vitamin D status, populations of ethnic minority are understudied in terms of setting target serum 25-hydroxyvitamin D concentrations and corresponding dietary requirements for vitamin D. In minority groups, prevention of vitamin D deficiency on a population basis is challenging due to the lack of clarity surrounding the metabolism and transport of vitamin D. Authoritative agencies have been unable to define pregnancy-specific dietary recommendations for vitamin D, owing to an absence of sufficient evidence to confirm whether nutritional requirements for vitamin D are altered during pregnancy. While the question of setting race- and pregnancy-specific dietary reference values for vitamin D has not been addressed to date, endemic vitamin D deficiency has been reported among gravidae worldwide, specifically among ethnic minorities and white women resident at high latitude. In light of the increased risk of nutritional rickets among infants of ethnic minority, coupled with growing evidence for potential non-skeletal roles of vitamin D in perinatal health, determination of the dietary vitamin D requirement that will prevent deficiency during pregnancy is a research priority. However, systematic approaches to establishing dietary requirements are limited by the quality of the available evidence and the under-representation of minority groups in clinical research. This review considers the evidence for racial differences in vitamin D status and response to vitamin D supplementation, with particular application to pregnancy-specific requirements among ethnic minorities resident at high latitudes.
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10
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Shieh A, Aloia JF. Assessing Vitamin D Status in African Americans and the Influence of Vitamin D on Skeletal Health Parameters. Endocrinol Metab Clin North Am 2017; 46:135-152. [PMID: 28131129 DOI: 10.1016/j.ecl.2016.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the United States, there is a significant disparity in vitamin D status among individuals of African versus European descent. Despite having lower total 25-hydroxyvitamin D levels compared with white Americans, African Americans have higher bone mineral density and lower fracture risk. This article reviews classical and nonclassical vitamin D physiology, describes whether total versus free 25-hydroxyvitamin D is a better marker of vitamin D status in African Americans, and summarizes the influence of vitamin D status and vitamin D supplementation on markers of vitamin D bioactivity (intestinal calcium absorption, parathyroid hormone secretion, bone mineral density, fracture) in African Americans.
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Affiliation(s)
- Albert Shieh
- Division of Geriatrics, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 10945 LeConte Avenue, Suite 2339, Los Angeles, CA 90095-1687, USA; Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, 10945 LeConte Avenue, Suite 2339, Los Angeles, CA 90095-1687, USA.
| | - John F Aloia
- Department of Medicine, Bone Mineral Research and Treatment Center, Dean Winthrop University Hospital Clinical Campus, Stony Brook University School of Medicine, 222 Station Plaza North, Suite 510, Mineola, NY 11501, USA
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11
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Lu JL, Molnar MZ, Ma JZ, George LK, Sumida K, Kalantar-Zadeh K, Kovesdy CP. Racial Differences in Association of Serum Calcium with Mortality and Incident Cardio- and Cerebrovascular Events. J Clin Endocrinol Metab 2016; 101:4851-4859. [PMID: 27631543 PMCID: PMC5155693 DOI: 10.1210/jc.2016-1802] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Abnormalities in calcium metabolism may potentially contribute to the development of vascular disease. Calcium metabolism may be different in African American (AA) vs white individuals, but the effect of race on the association of serum calcium with clinical outcomes remains unclear. OBJECTIVE This study sought to examine race-specific associations of serum calcium levels with mortality and with major incident cardiovascular events. DESIGN AND SETTING This was a historical cohort study in the U.S. Department of Veterans Affairs health care facilities. PARTICIPANTS Participants included veterans (n = 1 967 622) with estimated glomerular filtration rate ≥ 60 mL/min/1.73 m2. MAIN OUTCOME MEASURES The association between serum calcium levels with all-cause mortality, incident coronary heart disease (CHD), and ischemic stroke incidence was examined in multivariable adjusted Cox proportional hazards models, including an interaction term for calcium and race. RESULTS The association of calcium with all-cause mortality was U-shaped in both AA and white patients, but race modified the association of calcium with all-cause mortality. Compared with white patients, AA patients experienced lower risk of mortality when calcium was ≥ 8.8 mg/dL, with a statistically significant interaction (P < .001). Conversely, AA vs white race was associated with higher mortality when calcium was < 8.8 mg/dL. Calcium showed no significant association with ischemic stroke or CHD in both races; and race did not modify these associations (P = .37 and 0.11, respectively for interaction term). CONCLUSIONS Race modified the U-shaped association between calcium and all-cause mortality. Serum calcium is not associated with incident stroke or CHD in either AA or white patients. The race-specific difference in the association of calcium levels with mortality warrants further examination.
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Affiliation(s)
- Jun Ling Lu
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
| | - Miklos Z Molnar
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
| | - Jennie Z Ma
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
| | - Lekha K George
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
| | - Keiichi Sumida
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
| | - Kamyar Kalantar-Zadeh
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
| | - Csaba P Kovesdy
- Division of Nephrology (J.L.L., M.Z.M., L.K.G., K.S., C.P.K.), University of Tennessee Health Science Center, Memphis Tennessee 38163; Department of Public Health Sciences and Division of Nephrology, Department of Medicine (J.Z.M.), University of Virginia, Charlottesville, Virginia 22908; Nephrology Center (K.S.), Toranomon Hospital Kajigaya, Kanagawa 213-8587, Japan; Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension (K.K.-Z.), University of California-Irvine Medical Center, Orange, California 92868; and Nephrology Section (C.P.K.), Memphis VA Medical Center, Memphis, Tennessee 38104
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12
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Hanks LJ, Gutiérrez OM, Ashraf A, Casazza K. Bone Mineral Content as a Driver of Energy Expenditure in Prepubertal and Early Pubertal Boys. J Pediatr 2015; 166:1397-403. [PMID: 25841541 PMCID: PMC4446221 DOI: 10.1016/j.jpeds.2015.02.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/16/2015] [Accepted: 02/19/2015] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To examine the associations of bone and bone-secreted factors with measures of energy metabolism in prepubertal and early pubertal boys. STUDY DESIGN Participants in this cross-sectional, observational study included 37 (69% black, 31% white) boys, aged 7-12 years (Tanner stage <III). Dual-energy X-ray absorptiometry was used to measure bone mineral content (BMC) and percent body fat. Indirect calorimetry was used to assess resting energy expenditure (REE). Fasting blood levels of osteocalcin (OCN), fibroblast growth factor 23 (FGF23), insulin, glucose, precursor product of type I collagen (N-terminal pro-peptide) and type I collagen, and C-terminal cross-linked telopeptide were measured. Pearson correlations were performed to evaluate relationships among BMC, OCN, FGF23, fasting insulin and glucose, and REE. Multiple linear regression models were used to test associations between OCN and BMC (independent variables) with fasting insulin and glucose and with REE, adjusting for bone turnover markers and further adjusted for percent body fat. RESULTS BMC was correlated with REE and insulin. OCN was correlated with glucose in blacks only (r = 0.45, P < .05). FGF23 was not correlated with any markers of energy metabolism. BMC was associated with insulin level in blacks (β = 0.95, P = .001), which was attenuated by percent body fat (β = 0.47, P = .081). BMC was associated with REE in whites (β = 0.496.7, P < .05) and blacks (β = 619.5, P < .0001); but accounting for percent body fat attenuated the association in whites (β = 413.2, P = .078). CONCLUSION Our findings suggest that BMC is a determinant of fasting insulin and REE, and that the contribution of body fat appears to be race-specific. Endocrine effects of FGF23 and OCN on energy metabolism were not apparent. TRIAL REGISTRATION Registered with ClinicalTrials.gov: NCT02040740, NCT02040727, and NCT01410643.
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Affiliation(s)
- Lynae J. Hanks
- Department of Pediatrics, University of Alabama at Birmingham (UAB)
| | | | - Ambika Ashraf
- Department of Pediatrics, University of Alabama at Birmingham (UAB)
| | - Krista Casazza
- Department of Pediatrics, University of Alabama at Birmingham (UAB)
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14
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Im JG, Kim SH, Lee GY, Joung H, Park MJ. Inadequate calcium intake is highly prevalent in Korean children and adolescents: the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2010. Public Health Nutr 2014; 17:2489-95. [PMID: 24160303 PMCID: PMC10282339 DOI: 10.1017/s1368980013002826] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 08/21/2013] [Accepted: 09/04/2013] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The present study aimed to assess the adequacy of Ca intake and major food sources of Ca in Korean children and adolescents. DESIGN A cross-sectional study. SETTING Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2007-2010. We analysed the daily Ca intake, major food sources of Ca and the prevalence of inadequate Ca intake in the study population. Ca intake was categorized as inadequate when the participant's daily Ca intake was less than the Estimated Average Requirement. Subject The study population consisted of 7233 children and adolescents (3973 boys, 3260 girls; aged 1-18 years). RESULTS Mean Ca intake was 510·2 mg/d in boys and 431·7 mg/d in girls. Overall, 75·0 % of adolescents (boys 71·6 %, girls 79·1 %) had inadequate Ca intake. The prevalence of inadequate Ca intake increased significantly from toddlers (45-55 %) to adolescents (78-86 %) in both genders. The highest ranked food sources for Ca were dairy products (35·0 %), followed by vegetables (17·3 %), grains (11·3 %) and seafood (9·9 %). Ca intake from dairy products decreased significantly from 57 % in toddlers to 30 % in adolescents, while Ca intakes from other foods increased with age. CONCLUSIONS Inadequate Ca intake is highly prevalent and increased with age in Korean children and adolescents. It should be emphasized to encourage children and adolescents to eat more Ca-rich products to meet their Ca needs.
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Affiliation(s)
- Jong Geun Im
- Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, 761-1 Sanggye-7-dong, Nowon-gu, Seoul 139-707, Republic of Korea
| | - Shin Hye Kim
- Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, 761-1 Sanggye-7-dong, Nowon-gu, Seoul 139-707, Republic of Korea
| | - Gyeong-yoon Lee
- Public Health Nutrition, School of Public Health, Seoul National University, Seoul, Republic of Korea
| | - Hyojee Joung
- Public Health Nutrition, School of Public Health, Seoul National University, Seoul, Republic of Korea
| | - Mi-Jung Park
- Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, 761-1 Sanggye-7-dong, Nowon-gu, Seoul 139-707, Republic of Korea
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15
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Pettifor JM. Calcium and vitamin D metabolism in children in developing countries. ANNALS OF NUTRITION AND METABOLISM 2014; 64 Suppl 2:15-22. [PMID: 25341870 DOI: 10.1159/000365124] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Low dietary calcium intakes and poor vitamin D status are common findings in children living in developing countries. Despite many of the countries lying within the tropics and subtropics, overcrowding, atmospheric pollution, a lack of vitamin D-fortified foods, and social customs that limit skin exposure to sunlight are major factors in the development of vitamin D deficiency. Low dietary calcium intakes are typically observed as a consequence of a diet limited in dairy products and high in phytates and oxalates which reduce calcium bioavailability. Calcium intakes of many children are a third to a half of the recommended intakes for children living in developed countries, yet the consequences of these low intakes are poorly understood as there is limited research in this area. It appears that the body adapts very adequately to these low intakes through reducing renal calcium excretion and increasing fractional intestinal absorption. However, severe deficiencies of either calcium or vitamin D can result in nutritional rickets, and low dietary calcium intakes in association with vitamin D insufficiency act synergistically to exacerbate the development of rickets. Calcium supplementation in children from developing countries slightly increases bone mass, but the benefit is usually lost on withdrawal of the supplement. It is suggested that the major effect of calcium supplementation is on reducing the bone remodelling space rather than structurally increasing bone size or volumetric bone density. Limited evidence from one study raises concerns about the use of calcium supplements in children on habitually low calcium intakes as the previously supplemented group went through puberty earlier and had a final height several centimetres shorter than the controls.
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Affiliation(s)
- John M Pettifor
- MRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Kruger MC, de Winter RM, Becker PJ, Vorster HH. Changes in markers of bone turnover following urbanisation of black South African women. JOURNAL OF ENDOCRINOLOGY METABOLISM AND DIABETES OF SOUTH AFRICA 2014. [DOI: 10.1080/22201009.2004.10872329] [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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Abstract
The prevalence of osteoporosis and the incidence of age-related fragility fracture vary by ethnicity. There is greater than 10-fold variation in fracture probabilities between countries across the world. Mineral and bone metabolism are intimately interlinked, and both are known to exhibit patterns of daily variation, known as the diurnal rhythm (DR). Ethnic differences are described for Ca and P metabolism. The importance of these differences is described in detail between select ethnic groups, within the USA between African-Americans and White-Americans, between the Gambia and the UK and between China and the UK. Dietary Ca intake is higher in White-Americans compared with African-Americans, and is higher in White-British compared with Gambian and Chinese adults. Differences are observed also for plasma 25-hydroxy vitamin D, related to lifestyle differences, skin pigmentation and skin exposure to UVB-containing sunshine. Higher plasma 1,25-dihydroxy vitamin D and parathyroid hormone are observed in African-American compared with White-American adults. Plasma parathyroid hormone is also higher in Gambian adults and, in winter, in Chinese compared with White-British adults. There may be ethnic differences in the bone resorptive effects of parathyroid hormone, with a relative skeletal resistance to parathyroid hormone observed in some, but not all ethnic groups. Renal mineral excretion is also influenced by ethnicity; urinary Ca (uCa) and urinary P (uP) excretions are lower in African-Americans compared with White-Americans, and in Gambians compared with their White-British counterparts. Little is known about ethnic differences in the DR of Ca and P metabolism, but differences may be expected due to known differences in lifestyle factors, such as dietary intake and sleep/wake pattern. The ethnic-specific DR of Ca and P metabolism may influence the net balance of Ca and P conservation and bone remodelling. These ethnic differences in Ca, P and the bone metabolism may be important factors in the variation in skeletal health.
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Affiliation(s)
- J. Redmond
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge CB1 9NL, UK
| | | | - B. Zhou
- Department of Public health, Shenyang Medical College, 146 Huanghe North Street, Shenyang 110034, People's Republic of China
| | - A. Prentice
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge CB1 9NL, UK
- Medical Research Council Keneba, The Gambia
| | - I. Schoenmakers
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge CB1 9NL, UK
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18
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Ethnic differences in bone and mineral metabolism in healthy people and patients with CKD. Kidney Int 2013; 85:1283-9. [PMID: 24352156 DOI: 10.1038/ki.2013.443] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/07/2013] [Accepted: 08/15/2013] [Indexed: 12/24/2022]
Abstract
Several studies have shown racial differences in the regulation of mineral metabolism, in the acquisition of bone mass and structure of individuals. In this review, we examine ethnic differences in bone and mineral metabolism in normal individuals and in patients with chronic kidney disease. Black individuals have lower urinary excretion and increased intestinal calcium absorption, reduced levels of 25(OH)D, and high levels of 1.25(OH)2D and parathyroid hormone (PTH). Body phosphorus concentration is higher and the levels of FGF-23 are lower than in whites. Mineral density and bone architecture are better in black individuals. These differences translate into advantages for blacks who have stronger bones, less risk of fractures, and less cardiovascular calcification. In the United States of America, the prevalence of kidney disease is similar in different ethnic groups. However, black individuals progress more quickly to advanced stages of kidney disease than whites. This faster progression does not translate into increased mortality, higher in whites, especially in the first year of dialysis. Some ethnicity-related variations in mineral metabolism persist when individuals develop CKD. Therefore, black patients have lower serum calcium concentrations, less hyperphosphatemia, low levels of 25(OH)D, higher levels of PTH, and low levels of FGF-23 compared with white patients. Bone biopsy studies show that blacks have greater bone volume. The rate of fractures and cardiovascular diseases are also less frequent. Further studies are required to better understand the cellular and molecular bases of these racial differences in bone mineral metabolism and thus better treat patients.
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Hanks LJ, Casazza K, Ashraf AP, Ramanadham S, Ard J, Bray MS, Mark Beasley T, Fernandez JR. Vitamin D and calcium-sensing receptor polymorphisms differentially associate with resting energy expenditure in peripubertal children. J Bone Miner Metab 2013; 31:695-702. [PMID: 23546818 PMCID: PMC3965256 DOI: 10.1007/s00774-013-0454-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 03/13/2013] [Indexed: 01/08/2023]
Abstract
Given that calcium metabolism is influenced by genes and is tightly linked to energy-utilizing pathways, this study evaluated the association of single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and calcium-sensing receptor (CASR) with resting energy expenditure (REE). In 273 boys and girls, 7-12 years of age, cross-sectional REE was measured via indirect calorimetry, body composition by DXA, and dietary measures by 24-h recall. SNPs for VDR Cdx-2 (rs11568820) and CASR A986S (rs1801725) were genotyped using the Illumina Golden Gate assay. Multiple linear regression models were used to determine the association between SNPs and REE. African American carriers of the 'A' VDR Cdx2 allele had increased levels of REE in the overall sample, and this association was apparent among participants with an adiposity level of <25 % and 30 % body fat in males and females, respectively. For CASR, an association between carriers of the 'A' allele and REE was observed only in those in the upper median of calcium intake. VDR and CASR variants are associated with REE in children and are influenced by levels of calcium intake and adiposity. Our results bring awareness to mechanisms underlying the regulation of REE and biological and dietary influential factors.
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Affiliation(s)
- Lynae J Hanks
- Department of Nutrition Sciences, University of Alabama at Birmingham, Webb 445, 1720 Second Ave South, Birmingham, AL, 35294-3360, USA,
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20
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Palacios C, Wigertz K, Braun M, Martin BR, McCabe GP, McCabe L, Pratt JH, Peacock M, Weaver CM. Magnesium retention from metabolic-balance studies in female adolescents: impact of race, dietary salt, and calcium. Am J Clin Nutr 2013; 97:1014-9. [PMID: 23553157 PMCID: PMC3628374 DOI: 10.3945/ajcn.112.039867] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 02/05/2013] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Previously, we showed that black girls retained more calcium than white girls did and that salt loading negatively affected calcium retention. Racial differences likely exist in other bone minerals also, such as magnesium, in response to salt loading during growth. OBJECTIVE We studied racial differences in magnesium metabolism in response to dietary sodium and calcium during rapid bone growth. DESIGN Twenty-seven white and 40 black girls (11-15 y old) were studied for 3 wk while they consumed low-sodium (1.3 g/d) and high-sodium (3.8 g/d) diets by using a randomized-order, crossover metabolic study with 3 dietary calcium intakes; the magnesium dietary intake was fixed at 230 mg/d. Urine and feces were collected during each 3-wk period in 24-h pools and analyzed for magnesium. A mixed-model ANOVA was used to determine the effect of race and dietary sodium with calcium intake as a covariate. RESULTS Salt loading or calcium intake had no significant effect on urinary magnesium excretion. Blacks excreted significantly less urinary magnesium (mean ± SD: 83.8 ± 25.6 mg/d) than did whites (94.9 ± 27.3 mg/d; P < 0.05). No effects were observed in fecal magnesium excretion. Magnesium retention was higher with the low-sodium diet (50.1 ± 44.0 mg/d) than with the high-sodium diet (39.3 ± 49.8 mg/d) (P < 0.05), with no effects of race or calcium intake. Salt loading had no effect on biomarkers. Whites had higher 25-hydroxyvitamin D and insulin-like growth factor binding protein 3 but lower 1,25-dihydroxyvitamin D and parathyroid hormone concentrations. CONCLUSIONS Blacks excreted less urinary magnesium than did whites. Magnesium retention was similar between races but higher with the low-sodium diet. Kinetic studies are needed to fully explain magnesium homeostasis. This trial was registered at clinicaltrials.gov as NCT01564238.
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Affiliation(s)
- Cristina Palacios
- Nutrition Program, School of Public Health, University of Puerto Rico, San Juan, Puerto Rico.
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21
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Abstract
Calcium is the most abundant cation in the human body, of which approximately 99% occurs in bone, contributing to its rigidity and strength. Bone also functions as a reservoir of Ca for its role in multiple physiologic and biochemical processes. This article aims to provide a thorough understanding of the absorptive mechanisms and factors affecting these processes to enable one to better appreciate an individual's Ca needs, and to provide a rationale for correcting Ca deficiencies. An overview of Ca requirements and suggested dosing regimens is presented, with discussion of various Ca preparations and potential toxicities of Ca treatment.
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Affiliation(s)
- Ronald D Emkey
- Pennsylvania Regional Center for Arthritis & Osteoporosis Research, 1200 Broadcasting Road, Suite 200, Wyomissing, PA 19610, USA.
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22
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O'Brien KO, Donangelo CM, Ritchie LD, Gildengorin G, Abrams S, King JC. Serum 1,25-dihydroxyvitamin D and calcium intake affect rates of bone calcium deposition during pregnancy and the early postpartum period. Am J Clin Nutr 2012; 96:64-72. [PMID: 22648718 PMCID: PMC3374733 DOI: 10.3945/ajcn.111.029231] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 05/01/2012] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Factors affecting bone calcium deposition across pregnancy and lactation are not well characterized. OBJECTIVE The impact of maternal age, calcium intake, race-ethnicity, and vitamin D status on the rate of bone calcium deposition (VO+) was assessed across pregnancy and lactation. DESIGN Stable calcium isotopes were given to 46 women at pre- or early pregnancy (trimester 1), late pregnancy (trimester 3), and 3-10 wk postpartum. Three cohorts were included: 23 adolescents from Baltimore (MD), aged 16.5 ± 1.4 y (mean ± SD; Baltimore cohort); 13 adults from California, aged 29.5 ± 2.6 y (California cohort); and 10 adults from Brazil, aged 30.4 ± 4.0 y (Brazil cohort). The total exchangeable calcium pool, VO+, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D [1,25(OH)₂D], parathyroid hormone, and calcium intake were evaluated. RESULTS At trimester 3, inverse associations between 1,25(OH)₂D and VO+ were evident in the Baltimore (P = 0.059) and Brazil (P = 0.008) cohorts and in the whole group (P = 0.029); calcium intake was not a significant determinant of VO+ in any group during pregnancy. At postpartum, a significant positive association was evident between VO+ and calcium intake (P ≤ 0.002) and between VO+ and African ethnicity (P ≤ 0.004) in the whole group and within the Baltimore and Brazil cohorts. CONCLUSIONS Elevated 1,25(OH)₂D was associated with decreased rates of bone calcium deposition during late pregnancy, a finding that was particularly evident in pregnant adolescents and adult women with low calcium intakes. Higher dietary calcium intakes and African ethnicity were associated with elevated rates of bone calcium deposition in the postpartum period.
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UENISHI K, ISHIMI Y, NAKAMURA K, KODAMA H, ESASHI T. Dietary Reference Intakes for Japanese 2010: Macrominerals. J Nutr Sci Vitaminol (Tokyo) 2012. [DOI: 10.3177/jnsv.59.s83] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Jung J, Basile DP, Pratt JH. Sodium reabsorption in the thick ascending limb in relation to blood pressure: a clinical perspective. Hypertension 2011; 57:873-9. [PMID: 21403087 DOI: 10.1161/hypertensionaha.108.120246] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jeesun Jung
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
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25
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Park CY, Hill KM, Elble AE, Martin BR, DiMeglio LA, Peacock M, McCabe GP, Weaver CM. Daily supplementation with 25 μg cholecalciferol does not increase calcium absorption or skeletal retention in adolescent girls with low serum 25-hydroxyvitamin D. J Nutr 2010; 140:2139-44. [PMID: 20962148 DOI: 10.3945/jn.110.124891] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In healthy adolescents, cross-sectional studies show either no or negative relationships between serum 25-hydroxyvitamin D [25(OH)D] and calcium (Ca) absorption. Using a 2-period metabolic balance study, the effect of vitamin D supplementation on Ca absorption and retention in adolescent girls was investigated. Eleven girls aged 12-14 y with a mean entry serum 25(OH)D of 35.1 nmol/L consumed a controlled intake (providing 5 μg vitamin D and 1117 mg Ca/d) for two 3-wk metabolic balance periods separated by a 1-wk washout period. Sunlight exposure was minimized by sunscreen with a sun protection factor ≥ 15. After the first metabolic balance period, participants received 25 μg/d cholecalciferol supplementation for 4 wk. Fractional Ca absorption was measured in each metabolic balance period using a stable Ca isotope method. All urine and fecal samples were collected and analyzed to measure net Ca absorption and Ca retention. Paired t tests and correlations were used to analyze the data. Daily supplementation with 25 μg vitamin D resulted in a mean increase in serum 25(OH)D of 13.3 nmol/L (P < 0.01) but a decrease in fractional Ca absorption of 8.3% (P < 0.05) and no significant change in fasting serum 1,25-dihydroxyvitamin D, parathyroid hormone, net Ca absorption, or Ca skeletal retention. In pubertal girls with vitamin D status considered insufficient in adults, vitamin D supplementation of 25 μg/d for 4 wk did not improve fractional Ca absorption, net Ca absorption, or Ca retention.
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Affiliation(s)
- Clara Y Park
- Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907-2059, USA
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26
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Ribeiro RR, Santos-Ribeiro KD, Guerra-Junior G, Barros-Filho ADA. Comparison of bone quantity by ultrasound measurements of phalanges between white and black children living in Paraná, Brazil, with Europeans. Braz J Med Biol Res 2010; 43:976-81. [PMID: 20802978 DOI: 10.1590/s0100-879x2010007500089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 08/11/2010] [Indexed: 11/21/2022] Open
Abstract
The objective of this study was to determine bone quantity by ultrasound measurements of the proximal finger phalanges (AD-SoS = amplitude-dependent speed of sound) of healthy Brazilian schoolchildren living in Paraná, Brazil and to compare these values with European populations. The sample was composed of 1356 Brazilian schoolchildren of both genders (660 males, 696 females), aged 6 to 11 years, divided into white (840) and black (516) groups and compared to age- and gender-matched Europeans. AD-SoS of the schoolchildren increased significantly with age for both genders. Significantly higher AD-SoS values were observed for the white children (1916 ± 58) compared to their black counterparts (1898 ± 72) and for the female gender (1920 ± 61) compared to the male gender (1898 ± 66). Overall, the AD-SoS outcomes for females were similar to those of European studies. However, the AD-SoS of the Brazilian schoolchildren of both genders and skin colors was lower than that reported for children in Poland. AD-SoS outcomes for Brazilian schoolboys were similar to those obtained in Italian studies and were lower than those of the Spanish children. In conclusion, Brazilian schoolchildren of both genders and skin colors showed lower bone quantities than Polish children and Spanish males, and levels similar to Italian children and Spanish females.
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Affiliation(s)
- R R Ribeiro
- Centro de Investigação em Pediatria, Departamento de Pediatria, Universidade Estadual de Campinas, SP, Brasil
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27
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Building skeletons during adolescence: what is the target? Br J Nutr 2010; 103:467-8. [DOI: 10.1017/s0007114509992571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Yin J, Zhang Q, Liu A, Du W, Wang X, Hu X, Ma G. Factors affecting calcium balance in Chinese adolescents. Bone 2010; 46:162-6. [PMID: 19796716 DOI: 10.1016/j.bone.2009.09.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 09/21/2009] [Accepted: 09/21/2009] [Indexed: 11/18/2022]
Abstract
Chinese dietary reference intakes (DRIs) for calcium were developed mainly from studies conducted amongst Caucasians, yet a recent review showed that reference calcium intakes for Asians are likely to be different from those of Caucasians (Lee and Jiang, 2008). In order to develop calcium DRIs for Chinese adolescents, it is necessary to explore the characteristics and potential influencing factors of calcium metabolic balance in Chinese adolescents. A total of 80 students (15.1+/-0.8 years) were recruited stratified by gender from a 1-year calcium supplementation study. Subjects were randomly designed to four groups and supplemented with calcium carbonate tablets providing elemental calcium at 63, 354, 660, and 966 mg/day, respectively. Subjects consumed food from a 3-day cycle menu prepared by staff for 10 days. Elemental calcium in samples of foods, feces, and urine was determined in duplicates by inductively coupled plasma atomic emission spectrometry. The total calcium intake ranged from 352 to 1323 mg/day. The calcium apparent absorption efficiency and retention in boys were significantly higher than that in girls (68.7% vs. 46.4%, 480 mg/day vs. 204 mg/day, P<0.05). Calcium retention increased with calcium intakes, but did not reach a plateau. Calcium absorption efficiency in boys increased with calcium intake up to 665 mg/day, and decreased after that. In girls, calcium absorption efficiency decreased with calcium intake. Calcium absorption efficiency increased within 1 year after first spermatorrhea in boys, but decreased with pubertal development in girls. Sex, calcium intake, age, and pubertal development were the most important determinants of calcium absorption (R(2)=0.508, P<0.01) and retention (R(2)=0.745, P<0.05). This study indicates that sex, calcium intake, age, and pubertal development are important factors for calcium retention and absorption during growth, which should be considered for the development of calcium DRIs for Chinese adolescents.
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Affiliation(s)
- Jing Yin
- National Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, 7 Pan Jia Yuan Nan Li, Beijing 100021, China
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Moore C, Yee J, Malluche H, Rao DS, Monier-Faugere MC, Adams E, Daramola-Ogunwuyi O, Fehmi H, Bhat S, Osman-Malik Y. Relationship between bone histology and markers of bone and mineral metabolism in African-American hemodialysis patients. Clin J Am Soc Nephrol 2009; 4:1484-1493. [PMID: 19713297 DOI: 10.2215/cjn.01770408] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Racial differences in mineral metabolism exist in the chronic kidney disease population, especially as it relates to intact parathyroid hormone (iPTH) levels. Few data exist on the relationship of these markers to bone biopsy findings in African-American (AA) hemodialysis patients across the spectrum of renal osteodystrophy (ROD). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In prevalent AA hemodialysis subjects, we prospectively evaluated subjects by performing transiliac bone biopsy and correlating biochemical and clinical data to bone histology. RESULTS Study patients (n = 43) had an average age of 53.7 (11.6) yr, with dialysis vintage of 40.4 (24.5) mo, 30% with diabetes, and 51% male. Bone histology revealed adynamic bone disease (ABD) (16%), mild to moderate hyperparathyroidism (HPT) (72%), severe (12%) HPT, and no osteomalacia or mixed uremic osteodystrophy. At the time of biopsy, mean corrected calcium was 9.1, 8.9, and 9.4 mg/dl (P = 0.344); calcium-phosphorus (Ca X PO4) product was 42, 55, and 62 mg(2)/dl(2) (P = 0.002); phosphorus was 4.6, 6.2, and 6.7 mg/dl (P = 0.005); and iPTH was 225, 566, and 975 pg/ml (P = 0.006), respectively. Median values for bone-specific alkaline phosphatase (BS-AP) were 16, 34, and 64 ng/ml (P < 0.0001) among the three groups. CONCLUSIONS These data demonstrate that across the spectrum of ROD, iPTH levels are higher than expected in AA hemodialysis subjects. iPTH, PTH peptides, and bone-specific alkaline phosphatase correlated directly with histomorphometric measurements of bone turnover and when subjects were grouped by histologic diagnosis. Only 9.5% of subjects were simultaneously within suggested Kidney Disease Outcomes Quality Initiative (K/DOQI) ranges for Ca X PO4, phosphorus, and iPTH, of which 75% demonstrated ABD on biopsy.
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Affiliation(s)
- Carol Moore
- Division of Nephrology and Hypertension, Henry Ford Hospital, Detroit, Michigan, USA
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Adaptation of calcium absorption during treatment of nutritional rickets in Nigerian children. Br J Nutr 2008; 100:387-92. [PMID: 18197991 DOI: 10.1017/s0007114507901233] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Nutritional rickets in Nigerian children has been effectively treated with Ca supplementation. High values of Ca absorption efficiency have been observed in untreated children, but whether Ca absorption efficiency changes during treatment with Ca is unknown. Our objective in conducting this study was to identify the effect of Ca therapy on Ca absorptive efficiency in children with primary Ca-deficient nutritional rickets. Twelve children with radiographically active rickets, 2 to 14 years of age (median 39 months) participated in the study. We assessed dietary Ca intake via dietary recalls, and measured biochemical markers of Ca and vitamin D homeostasis. Fractional Ca absorption was measured using a dual tracer stable isotope method, before and after 2 weeks of treatment with 15.0 mmol elemental Ca daily. Ten children had adequate urine collection for inclusion in the analysis. Usual dietary Ca intake was 4.2 (SD 1.0) mmol/d. The median Ca absorption prior to treatment was 72 % (range 52-97 %) and decreased significantly to 57 % (31-84 %) (P = 0.004) after 2 weeks of supplementation. We conclude that Nigerian children with rickets adapt to Ca supplementation with a small decrease in Ca absorptive capacity, but retain very high absorptive levels during supplementation. Overall Ca absorption efficiency was comparable with that identified in other populations with low Ca intakes. These data demonstrate that although absorptive capacity is regulated by supplementation, recovery from rickets likely occurs through efficient use of both dietary and supplemental Ca.
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Reinwald S, Weaver CM, Kester JJ. The health benefits of calcium citrate malate: a review of the supporting science. ADVANCES IN FOOD AND NUTRITION RESEARCH 2008; 54:219-346. [PMID: 18291308 DOI: 10.1016/s1043-4526(07)00006-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There has been considerable investigation into the health benefits of calcium citrate malate (CCM) since it was first patented in the late 1980s. This chapter is a comprehensive summary of the supporting science and available evidence on the bioavailability and health benefits of consuming CCM. It highlights the important roles that CCM can play during various life stages. CCM has been shown to facilitate calcium retention and bone accrual in children and adolescents. In adults, it effectively promotes the consolidation and maintenance of bone mass. In conjunction with vitamin D, CCM also decreases bone fracture risk in the elderly, slows the rate of bone loss in old age, and is of benefit to the health and well-being of postmenopausal women. CCM is exceptional in that it confers many unique benefits that go beyond bone health. Unlike other calcium sources that necessitate supplementation be in conjunction with a meal to ensure an appreciable benefit is derived, CCM can be consumed with or without food and delivers a significant nutritional benefit to individuals of all ages. The chemistry of CCM makes it a particularly beneficial calcium source for individuals with hypochlorydia or achlorydia, which generally includes the elderly and those on medications that decrease gastric acid secretion. CCM is also recognized as a calcium source that does not increase the risk of kidney stones, and in fact it protects against stone-forming potential. The versatile nature of CCM makes it a convenient and practical calcium salt for use in moist foods and beverages. The major factor that may preclude selection of CCM as a preferred calcium source is the higher cost compared to other sources of calcium commonly used for fortification (e.g., calcium carbonate and tricalcium phosphate). However, formation of CCM directly within beverages or other fluid foods and/or preparations, and the addition of a concentrated CCM solution or slurry, are relatively cost-effective methods by which CCM can be incorporated into finished food and beverage products.
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Affiliation(s)
- Susan Reinwald
- Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907, USA
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Abstract
The fact that fracture risk is lower and BMD is higher in blacks compared with whites is surprising in light of what is known about vitamin D status in blacks. Mean 25(OH)D levels are lower in blacks than whites at all stages of life, and a greater proportion of blacks meet criteria for vitamin D deficiency. The racial difference in serum 25(OH)D level is primarily caused by increased pigmentation reducing vitamin D production in the skin. In response to lower 25(OH)D levels and lower average calcium intake, blacks have higher average PTH levels and a higher prevalence of secondary hyperparathyroidism (twice the prevalence compared with whites for both sexes). This is associated with higher average levels of 1,25(OH)(2)D and lower urinary calcium excretion but not higher biochemical indices of bone turnover. In fact, in general, biochemical indices of bone formation (particularly osteocalcin levels) are lower in blacks. Bone formation rates assessed histomorphometrically are also lower, although wall thickness is maintained. During a 24-h PTH infusion, increments in levels of three different bone resorption markers are significantly lower in blacks than in whites, providing direct confirmation of the thesis that the black skeleton is resistant to the bone-resorbing effects of PTH, whereas renal sensitivity to PTH is maintained or perhaps even enhanced. Vitamin D supplementation studies in black women have shown inconsistent benefits to BMD. Skeletal and renal adaptations to vitamin D deficiency in blacks might be so effective that vitamin D supplementation might not confer any further benefit to the black skeleton. Benefits of vitamin D supplements in blacks may still play a role, however, in the prevention of other chronic diseases.
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Braun M, Palacios C, Wigertz K, Jackman LA, Bryant RJ, McCabe LD, Martin BR, McCabe GP, Peacock M, Weaver CM. Racial differences in skeletal calcium retention in adolescent girls with varied controlled calcium intakes. Am J Clin Nutr 2007; 85:1657-63. [PMID: 17556706 DOI: 10.1093/ajcn/85.6.1657] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Higher bone mass in blacks than in whites has been related to greater calcium utilization efficiency. Dietary calcium requirements for maximal skeletal calcium accretion during puberty may differ between the races. OBJECTIVE This study compared the relation between calcium intake and calcium retention in black and white adolescent girls. DESIGN A range of controlled calcium intakes (760-1981 mg Ca/d) were used in 3-wk controlled balance studies. Some subjects were studied more than once; a total of 182 observations from 55 black girls and 66 white girls were analyzed. RESULTS Blacks had 185 +/- 32 mg/d greater mean skeletal calcium retention than did whites (P < 0.0001) at all calcium intakes as a result of significantly greater net calcium absorption (P < 0.001) and lower calcium excretion (P < 0.0001). CONCLUSIONS Dietary calcium requirements did not differ with race. Higher calcium retention at all calcium intakes during adolescence may underlie the higher bone mineral content of adult blacks than of adult whites.
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Affiliation(s)
- Michelle Braun
- Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907, USA
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34
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Abrams SA, Strewler GJ. Adolescence: How do we increase intestinal calcium absorption to allow for bone mineral mass accumulation? ACTA ACUST UNITED AC 2007. [DOI: 10.1138/20070260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Tylavsky FA, Ryder KA, Lyytikäinen A, Cheng S. Vitamin D, parathyroid hormone, and bone mass in adolescents. J Nutr 2005; 135:2735S-8S. [PMID: 16251640 DOI: 10.1093/jn/135.11.2735s] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This article provides a review of the evidence identifying the factors related to vitamin D status in adolescents. The prevalence of vitamin D deficiency based on 25-hydroxyvitamin D [25(OH)D] of <25 nmol/L ranges from 0 to 32% depending on the season measured and the latitude of the population assessed. The factors that have been reported to affect serum 25(OH)D in adolescents include ethnicity, gender, puberty stage, parathyroid hormone (PTH), dietary vitamin D intake, and sun exposure. Vitamin D supplementation studies are limited to small populations and with supplementation focused on winter months when sunlight may be inadequate. The effects of vitamin D status and supplementation on bone assessment provide varied results. Differences in study design, modalities of bone assessment, and stage of puberty could contribute to disparate findings. Overall, the results from the available literature provide more questions than answers concerning the role of vitamin D in bone accrual in adolescents.
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Rosado JL, Díaz M, Rosas A, Griffit I, García OP. Calcium absorption from corn tortilla is relatively high and is dependent upon calcium content and liming in Mexican women. J Nutr 2005; 135:2578-81. [PMID: 16251614 DOI: 10.1093/jn/135.11.2578] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Corn tortillas are the staple food of Mexico. During their preparation, calcium is added to the tortillas; therefore, tortillas are the main source of calcium for a large proportion of the population. The bioavailability of calcium from lime-treated tortillas in humans is not known. The objectives of the present study were to determine calcium absorption from corn tortilla, to determine the effect of lime treatment on calcium absorption from corn tortilla, and to compare calcium absorption from tortilla prepared with a commercial corn flour and tortillas prepared with the traditional lime treatment at home. Nonpregnant, nonlactating women (n = 9) were administered 3 different treatments: 1) 180 g of corn tortilla prepared from corn flour with no lime treatment (CF), 2) 180 g of corn tortilla prepared from lime-treated commercial corn flour (LTCCF), or 3) 180 g of corn tortillas prepared from lime-treated home-prepared corn flour (LTHCF). Calcium absorption was measured using an established dual-tracer stable isotope technique. Calcium absorption of CF, LTCCF, and LTHCF was (mean +/- SD): 44 +/- 3.2, 32 +/- 4.4, and 30 +/- 2.4%, respectively; the fractional calcium absorption from CF differed from that of either LTCCF or LTHCF (P < 0.01). The total amount of calcium absorbed per treatment was higher in LTHCF (98.10 mg +/- 21.7) than in LTCCF (59.9 mg +/- 23.7, P < 0.001) and CF (3.78 mg +/- 0.9, P < 0.0.001). In conclusion, calcium absorption from corn tortillas is high and dependent on calcium concentration. The addition of calcium during lime treatment increases calcium concentration and total calcium absorption.
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Affiliation(s)
- Jorge L Rosado
- Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Querétaro, México.
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Abstract
Adequate dietary calcium and bone-stimulating exercise during growth are known to affect skeletal development, but the combined effects of dietary calcium and osteogenic exercise have received scant attention. Animal research has showed a compensatory effect of impact loading on calcium-deprived bones, while various human studies have suggested compensatory, additive, or possibly synergistic effects in certain skeletal locations. Current evidence suggests that the best strategy for strong bones by the end of childhood may be either high-impact exercise with a moderate or greater calcium intake or a combination of moderate-impact exercise and adequate calcium during growth.
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Affiliation(s)
- Jo M Welch
- School of Health and Human Performance, Dalhousie University, Halifax, Nova Scotia, Canada
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Abrams SA, Griffin IJ, Hawthorne KM, Gunn SK, Gundberg CM, Carpenter TO. Relationships among vitamin D levels, parathyroid hormone, and calcium absorption in young adolescents. J Clin Endocrinol Metab 2005; 90:5576-81. [PMID: 16076940 PMCID: PMC1283091 DOI: 10.1210/jc.2005-1021] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Evidence suggests that vitamin D status in adults, as assessed by serum 25-hydroxyvitamin D (25-OHD), is positively associated with calcium absorption fraction and inversely associated with serum PTH. Few comparable pediatric data exist. OBJECTIVES The objective of this study was to evaluate the relationships among vitamin D status, PTH, and calcium absorption in midpubertal boys and girls. METHODS Calcium absorption was measured as part of an evaluation of the effects of prebiotics (inulin-type fructans) using a stable isotope method in 93 young adolescents, 12.7 +/- 1.0 yr of age, receiving diets averaging approximately 900 mg/d calcium. RESULTS A significant positive relation to calcium absorption was found for serum 1,25-dihydroxyvitamin D (P = 0.048) and PTH (P = 0.007), but not for 25-OHD (P = 0.77). PTH was significantly inversely related to 25-OHD and was positively related to serum 1,25-dihydroxyvitamin D and osteocalcin. PTH was marginally significantly inversely related to lumbar spinal, but not whole body, bone mineral density. CONCLUSIONS These data suggest that in adolescents, especially in the presence of vitamin D insufficiency, PTH secretion increases to adapt to higher rates of bone formation associated with growth. This results in higher serum 1,25(OH)2D concentrations and increased calcium absorption results. Vitamin D status, as reflected by the serum 25-OHD level, is not closely related to calcium absorption. Whether adaptation to low serum 25-OHD is adequate under physiologically stressful situations, including those leading to very low serum 25-OHD levels, is unknown.
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Affiliation(s)
- Steven A Abrams
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, 1100 Bates Street, Houston, Texas 77030, USA.
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Griffin IJ, Abrams SA. Methodological considerations in measuring human calcium absorption: relevance to study the effects of inulin-type fructans. Br J Nutr 2005; 93 Suppl 1:S105-10. [PMID: 15877883 DOI: 10.1079/bjn20041344] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
During the last 50 years, a variety of methods have been developed to estimate Ca absorption in man. Mass balances were initially used, but these were unable to accurately measure fractional Ca absorption because they cannot distinguish unabsorbed dietary Ca from endogenous faecal Ca excretion (excretion of previously absorbed Ca back into the gut). A number of isotopic methods have been developed that can measure true fractional Ca absorption, employing radioisotopes, stable isotopes, or both. Different methods involve collection of urine, faecal or plasma samples. Of the currently available methods, the dual isotope tracer method with a timed urine collection is probably the most precise and reliable. It is also relatively straightforward to carry out and avoids the need for a faecal collection. The purpose of the present paper is to discuss the general advantages and disadvantages of the different methods of Ca absorption. In addition, the limitations the different methods have in examining the possible effects of non-digestible oligosaccharides on Ca absorption will be discussed.
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Affiliation(s)
- Ian J Griffin
- USDA/ARS Children's Nutrition Research Center, and Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, TX 77030, USA.
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Kim K, Johnson JA, Derendorf H. Differences in drug pharmacokinetics between East Asians and Caucasians and the role of genetic polymorphisms. J Clin Pharmacol 2005; 44:1083-105. [PMID: 15342610 DOI: 10.1177/0091270004268128] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Interethnic variability in pharmacokinetics can cause unexpected outcomes such as therapeutic failure, adverse effects, and toxicity in subjects of different ethnic origin undergoing medical treatment. It is important to realize that both genetic and environmental factors can lead to these differences among ethnic groups. The International Conference on Harmonization (ICH) published a guidance to facilitate the registration of drugs among ICH regions (European Union, Japan, the United States) by recommending a framework for evaluating the impact of ethnic factors on a drug's effect, as well as its efficacy and safety at a particular dosage and dosage regimen. This review focuses on the pharmacokinetic differences between East Asians and Caucasians. Differences in metabolism between East Asians and Caucasians are common, especially in the activity of several phase I enzymes such as CYP2D6 and the CYP2C subfamily. Before drug therapy, identification of either the genotype and/or the phenotype for these enzymes may be of therapeutic value, particularly for drugs with a narrow therapeutic index. Furthermore, these differences are relevant for international drug approval when regulatory agencies must decide if they accept results from clinical trials performed in other parts of the world.
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Affiliation(s)
- Kiman Kim
- Department of Pharmaceutics, University of Florida, Gainesville, FL 32610, USA
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Abrams SA, Griffin IJ, Hicks PD, Gunn SK. Pubertal girls only partially adapt to low dietary calcium intakes. J Bone Miner Res 2004; 19:759-63. [PMID: 15068499 DOI: 10.1359/jbmr.040122] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Revised: 12/02/2003] [Accepted: 01/16/2004] [Indexed: 11/18/2022]
Abstract
UNLABELLED We evaluated the effects of low calcium in the diets of young adolescent girls. We measured calcium absorption and excretion using stable isotopes. We found partial adaptation to low intakes but a persistent large deficit relative to recommended intakes. Low calcium intakes pose a substantial risk of inadequate calcium retention. INTRODUCTION A substantial number of adolescent girls in the United States have habitual calcium intakes <500 mg/day (about 40% of the current recommended intake). The ability to adapt to these very low intakes by increasing calcium absorption and decreasing calcium excretion is not known. We sought to determine the effects of recommended (REC-Ca) versus very low (LO-Ca) calcium intakes on calcium absorption and excretion in white and black girls. MATERIALS AND METHODS Pubertal, but premenarcheal girls, were adapted to low or recommended calcium intakes for at least 2 weeks before each study. Calcium absorption (n = 51) and endogenous fecal calcium excretion (n = 36 of the 51) were determined by dual-tracer stable isotope studies. Subjects were then switched to the other diet for at least 6 weeks, and the study was repeated. RESULTS Calcium intake was 389 +/- 10 mg/day on LO-Ca and 1259 +/- 35 mg/day on REC-Ca diets. Fractional absorption increased from 44.9 +/- 1.9% on REC-Ca to 63.4 +/- 1.7% on LO-Ca (p < 0.01), but the net calcium absorption remained less than one-half the value on LO-Ca as on REC-Ca. Despite decreases in both endogenous fecal calcium excretion and urinary calcium excretion, net calcium balance was much lower on LO-Ca compared with REC-Ca1 (131 +/- 14 versus 349 +/- 32 mg/day, respectively; p < 0.001). We found significantly lower urinary calcium excretion but not calcium absorption in black girls compared with white girls. CONCLUSIONS Very low calcium intakes are only partially adapted to by increased absorption and decreased excretion. Very low calcium intakes place both white and black pubertal girls at substantial risk for inadequate calcium retention.
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Affiliation(s)
- Steven A Abrams
- U.S. Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA.
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O'Brien KO, Nathanson MS, Mancini J, Witter FR. Calcium absorption is significantly higher in adolescents during pregnancy than in the early postpartum period. Am J Clin Nutr 2004; 78:1188-93. [PMID: 14668282 DOI: 10.1093/ajcn/78.6.1188] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Early childbearing may limit skeletal consolidation and increase calcium demands in adolescents. OBJECTIVE The purpose of this study was to characterize calcium absorption in pregnant and lactating adolescents. DESIGN Fractional calcium absorption was evaluated in 23 adolescents (mean +/- SD age: 16.5 +/- 1.4 y) during the third trimester of pregnancy (34.7 +/- 1.0 wk gestation) and again in 15 of these adolescents 31 +/- 8 d after delivery. Eight adolescents were breastfeeding their infants during the follow-up study. Fractional calcium absorption was determined by using oral ((46)Ca or (44)Ca) and intravenous ((42)Ca) stable calcium isotopes. Total-body and lumbar spine bone mineral density were measured in adolescents during the postpartum period by using dual-energy X-ray absorptiometry. RESULTS Fractional calcium absorption was significantly greater during pregnancy than at 3-4 wk postpartum [0.526 +/- 0.152 (n = 23) compared with 0.297 +/- 0.108 (n = 15); P < 0.0001]. Lumbar spine z scores measured 19-44 d after delivery (n = 15) were significantly associated with calcium intake during pregnancy (y = -3.53 + 0.107x; R(2) = 0.355, P < 0.02) and were inversely related to fractional calcium absorption during pregnancy (y = 3.489 - 6.66x; R(2) = 0.52, P = 0.002). A total of 33% (5/15) of adolescents had lumbar spine z scores that met the definition of osteopenia (n = 3) or osteoporosis (n = 2) in the early postpartum period. CONCLUSIONS Calcium absorption in adolescents was significantly higher during the third trimester of pregnancy than in the early postpartum period, and higher calcium intakes during pregnancy appeared to be protective against loss of trabecular bone at the lumbar spine.
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Affiliation(s)
- Kimberly O O'Brien
- Center for Human Nutrition, The Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe Street, Room 2041, Baltimore, MD 21205-2179, USA.
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Opotowsky AR, Bilezikian JP. Racial differences in the effect of early milk consumption on peak and postmenopausal bone mineral density. J Bone Miner Res 2003; 18:1978-88. [PMID: 14606510 DOI: 10.1359/jbmr.2003.18.11.1978] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED Studies of the effect of milk consumption on bone density have focused on white women. The applicability to other races is unclear. This study of 4316 women found a racial difference in the effect of early milk consumption on bone. Further study is required to evaluate the etiology of this difference. INTRODUCTION Early milk consumption has been found to influence bone mineral density positively throughout life. Previous studies leading to this finding focused on white women; there are no data to support the view that black women also gain an equivalent benefit from early milk consumption. MATERIALS AND METHODS Using data from the Third National Health and Nutrition Examination Survey (NHANES III), we analyzed the relationship between reported childhood and teenage milk consumption and current hip bone mineral density at four sites (femoral neck, trochanter, intertrochanter, and total hip) among postmenopausal and 20- to 39-year-old non-Hispanic white (NHW) and black (NHB) women. Potential confounding variables were accounted for in the analysis. RESULTS Controlling for age and body mass index, teenage milk consumption was significantly associated with higher bone mineral density at all four sites among both postmenopausal and 20- to 39-year-old white women, but was not associated with bone mineral density at any site among black women. A similar pattern was observed for childhood milk intake. The interaction between race and teenage milk consumption significantly explained postmenopausal bone mineral density at all sites, whereas the interaction between race and teenage milk consumption was significant at two of the four sites among the 20- to 39-year-old women. CONCLUSION The results show racial differences in the effect of early milk consumption on peak and postmenopausal bone mineral density.
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Affiliation(s)
- Alexander R Opotowsky
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
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Wang MC, Crawford PB, Hudes M, Van Loan M, Siemering K, Bachrach LK. Diet in midpuberty and sedentary activity in prepuberty predict peak bone mass. Am J Clin Nutr 2003; 77:495-503. [PMID: 12540413 DOI: 10.1093/ajcn/77.2.495] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND An average daily calcium intake of 1300 mg is recommended for North American adolescents aged 9-18 y. However, questions remain about these recommendations. OBJECTIVE We assessed whether there is a stage of puberty when dietary calcium is more strongly related to peak bone mass, as indicated by young adult bone mass (YABM); whether dietary calcium intake > 1000 mg/d in adolescence is associated with higher YABM; and whether race affects any of these associations between dietary calcium and YABM. Secondarily, we evaluated relations between sedentariness and YABM. DESIGN In a retrospective cohort study, we recruited 693 black and white women aged 21-24 y who had participated in the 10-y National Heart, Lung, and Blood Institute Growth and Health Study and measured YABM with the use of dual-energy X-ray absorptiometry. Dietary calcium and sedentary activity data, gathered through 3-d food records and self-reports of television-video viewing at 8 annual examinations, were averaged over 3 pubertal stages. Complete data were available from 161 black and 180 white females. Multiple regression, controlling for race, weight, and height, was applied to assess diet and activity relations with YABM. RESULTS Dietary calcium was most strongly associated with YABM in midpuberty. Calcium intake > 1000 mg/d was associated with higher YABM, but this association was not significant at all skeletal sites. Race did not affect the observed relations between calcium and YABM. Sedentary activity in prepuberty was inversely associated with YABM. CONCLUSIONS Interventions should focus on ensuring adequate calcium intake in midpuberty and on minimizing sedentariness in prepuberty.
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Affiliation(s)
- May-Choo Wang
- Department of Nutritional Sciences and the School of Public Health, University of California, Berkeley, 94720-7360, USA.
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47
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Energy balance, body composition, and puberty in children and adolescents: importance of ethnicity. ACTA ACUST UNITED AC 2003. [DOI: 10.1097/00060793-200302000-00003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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48
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Lanphear BP, Dietrich KN, Berger O. Prevention of lead toxicity in US children. AMBULATORY PEDIATRICS : THE OFFICIAL JOURNAL OF THE AMBULATORY PEDIATRIC ASSOCIATION 2003; 3:27-36. [PMID: 12540251 DOI: 10.1367/1539-4409(2003)003<0027:poltiu>2.0.co;2] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
During the past 2 decades, the proportion of US children who have blood lead concentrations of 10 microg/dL or higher declined by over 80% after the elimination of leaded gasoline and lead solder from canned foods, and a ban on leaded paint used in housing and other consumer products. Fatalities and symptomatic lead poisoning are now rare. Residential lead hazards, which are exceedingly difficult to control, are currently the major source of lead intake for children. Undue lead exposure has retreated into 2 major risk groups; impoverished children who live in older, poorly maintained rental housing and more affluent children who live in older housing undergoing renovation. Despite the dramatic decline in children's blood lead levels, lead toxicity remains epidemic among impoverished children who live in older rental housing, especially those who live in the northeastern and midwestern regions of the United States. There are increasing data linking lead exposure with other systemic effects including delinquency, dental caries, and learning problems. Moreover, there is evidence indicating that there is no discernible threshold for lead-associated cognitive deficits. Thus, it is increasingly important to shift our efforts toward the primary prevention of childhood lead exposure from residential hazards. This article reviews the epidemiology and control of childhood lead exposure, focusing especially on steps necessary to shift toward primary prevention.
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Affiliation(s)
- Bruce P Lanphear
- Cincinnati Children's Environmental Health Center, Department of Pediatrics, Children's Hospital Medical Center, Ohio 45229, USA.
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Wastney ME, Martin BR, Bryant RJ, Weaver CM. Calcium Utilization in Young Women: New Insights from Modeling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 537:193-205. [PMID: 14995037 DOI: 10.1007/978-1-4419-9019-8_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Meryl E Wastney
- Metabolic Modeling Services Ltd., Hamilton 2030, Dalesford, New Zealand.
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50
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Pratt JH, Ambrosius WT, Agarwal R, Eckert GJ, Newman S. Racial difference in the activity of the amiloride-sensitive epithelial sodium channel. Hypertension 2002; 40:903-8. [PMID: 12468577 DOI: 10.1161/01.hyp.0000039749.75068.f4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Compared with whites, blacks appear to retain additional sodium that suppresses secretion of renin and aldosterone. The epithelial sodium channel (ENaC) is an aldosterone-regulated site for sodium reabsorption. ENaC activity could be higher in blacks, contributing to sodium retention or, alternatively, lower because of reduced stimulation by aldosterone. To examine the level of ENaC activity in blacks relative to whites, blood pressure (BP) responses to amiloride (5 mg/d), an inhibitor of ENaC, were measured in 20 black and 25 white normotensive young people. After 1 week, systolic BP decreased by 3.0+/-9.2 (SD) and diastolic by 2.8+/-8.3 mm Hg in the whites, whereas systolic BP increased by 2.5+/-7.1 and diastolic by 3.8+/-8.0 mm Hg in the blacks; the racial difference in the BP response was significant for both systolic (P=0.034) and diastolic BP (P=0.010). As ENaC activity increases, renal secretion of potassium increases proportionately, and in a larger sample of subjects, the urinary potassium excretion rate was lower in the blacks (n=301) than in the whites (n=461): 3.2+/-0.1 versus 3.8+/-0.1 mmol/mmol creatinine (P=0.0001). The concentration of serum potassium was higher in the blacks (n=81) than in the whites (n=167): 4.36+/-0.05 versus 4.21+/-0.03 (P=0.012). In summary, a favorable BP response to amiloride in the whites as well as the evidence for greater retention of potassium in the blacks is consistent with blacks having less ENaC activity than whites. We suggest that increased sodium retention in blacks occurring at other nephron sites suppresses aldosterone secretion and in turn ENaC function.
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Affiliation(s)
- J Howard Pratt
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Ind, USA.
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