@article{524b466f84bf499c952fe628c9ec42e2,
title = "Effects of Vitamin D Supplementation on C-peptide and 25-hydroxyvitamin D Concentrations at 3 and 6 Months",
abstract = "The link between African-Americans' disproportionate rates of diabetes, obesity and vitamin D deficiency may be marked by C-peptide as an indicator of insulin secretion. We hypothesize that vitamin D supplementation will increase C-peptide, a marker of insulin secretion. During 3 winters from 2007-2010, 328 healthy African-Americans (median age, 51 years) living in Boston, MA were randomized into a 4-arm, double-blind trial for 3 months of placebo, 1000, 2000, or 4000 IU of vitamin D3. The differences in non-fasting C-peptide between baseline and 3 months were -0.44 ng/mL for those receiving placebo, -0.10 ng/mL for those receiving 1000 IU/d, 0 ng/mL for those receiving 2000 IU/d, 1.24 ng/mL for those receiving 4000 IU/d (C-peptide increased 0.42 ng/mL for each additional 1000 IU/d of vitamin D3, p < 0.001). Vitamin D supplementation increased C-peptide in overweight African-Americans and may be compatible with other recommendations for diabetes prevention and management including weight loss and increased physical activity.",
author = "Chandler, {Paulette D.} and Giovannucci, {Edward L.} and Scott, {Jamil B.} and Bennett, {Gary G.} and Kimmie Ng and Chan, {Andrew T.} and Hollis, {Bruce W.} and Nader Rifai and Emmons, {Karen M.} and Fuchs, {Charles S.} and Drake, {Bettina F.}",
note = "Funding Information: This trial was funded by the National Cancer Institute (U01CA138962 [Dr. Chandler]; Office of Dietary Supplements (3P50 CA127003 [Dr. Scott]); K07CA148894 [Dr Ng]; K22CA126992; 5K05CA124415 [Dr Emmons]; K24DK098311 [Dr.Chan]), the Department of Defense Prostate Cancer Research Program (PC081669 [Dr Drake]), the American Society of Clinical Oncology Career Development Award (Dr Ng), and Pharmavite LLC (Mission Hill, CA). These funding sources had no role in the conception or conduct of the study, took no part in the data collection or analysis, and had no role in the drafting, review, or approval of the article. Pharmavite LLC provided vitamin D and the placebo: We would like to thank Cara Marcus, MSLIS, AHIP, Director of Library Services, Brigham and Women{\textquoteright}s Faulkner Hospital for facilitating access to reference articles and Yiqing Song, MD, ScD for reviewing the manuscript and Camille A. Clarke, MD for assistance with editing manuscript. This work was conducted with support from Harvard Catalyst | The Harvard Clinical and Translational Science Center (National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health Award UL1 TR001102) and financial contributions from Harvard University and its affiliated academic healthcare centers. The content is solely the responsibility of the authors and does not necessarily represent the official views of Harvard Catalyst, Harvard University and its affiliated academic healthcare centers, or the National Institutes of Health. Publisher Copyright: {\textcopyright} 2015 Macmillan Publishers Limited.",
year = "2015",
month = jun,
day = "22",
doi = "10.1038/srep10411",
language = "English",
volume = "5",
journal = "Scientific Reports",
issn = "2045-2322",
}