@article{2f68a7e4e40544b0b08cc19d519f863c,
title = "Intratrial exposure to vitamin d and new-onset diabetes among adults with prediabetes: A secondary analysis from the vitamin d and type 2 diabetes (d2d) study",
abstract = "OBJECTIVE Postrandomization biases may influence the estimate of efficacy of supplemental vitamin D in diabetes prevention trials. In the Vitamin D and Type 2 Diabetes (D2d) study, repeated measures of serum 25-hydroxyvitamin D [25(OH)D] level provided an opportunity to test whether intratrial vitamin D exposure affected diabetes risk and whether the effect was modified by trial assignment (vitamin D vs. placebo). RESEARCH DESIGN AND METHODS The D2d study compared the effect of daily supplementation with 100 μg (4,000 units) of vitamin D3 versus placebo on new-onset diabetes in adults with pre-diabetes. Intratrial vitamin D exposure was calculated as the cumulative rolling mean of annual serum 25(OH)D measurements. Hazard ratios for diabetes among participants who had intratrial 25(OH)D levels of <50, 75–99, 100–124, and ≥125 nmol/L were compared with those with levels of 50–74 nmol/L (the range considered adequate by the National Academy of Medicine) in the entire cohort and by trial assignment. RESULTS There was an interaction of trial assignment with intratrial 25(OH)D level in predicting diabetes risk (interaction P = 0.018). The hazard ratio for diabetes for an increase of 25 nmol/L in intratrial 25(OH)D level was 0.75 (95% CI 0.68–0.82) among those assigned to vitamin D and 0.90 (0.80–1.02) among those assigned to placebo. The hazard ratios for diabetes among participants treated with vitamin D who maintained intratrial 25(OH)D levels of 100–124 and ≥125 nmol/L were 0.48 (0.29– 0.80) and 0.29 (0.17–0.50), respectively, compared with those who maintained a level of 50–74 nmol/L. CONCLUSIONS Daily vitamin D supplementation to maintain a serum 25(OH)D level ≥100 nmol/L is a promising approach to reducing the risk of diabetes in adults with prediabetes.",
author = "{D2d Research Group} and Bess Dawson-Hughes and Staten, {Myrlene A.} and Knowler, {William C.} and Jason Nelson and Vickery, {Ellen M.} and Leblanc, {Erin S.} and Neff, {Lisa M.} and Jean Park and Pittas, {Anastassios G.}",
note = "Funding Information: The authors thank the D2d investigators, staff, and trial participants for dedication and commitment to the trial. Funding. The D2d study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases and the Office of Dietary Supple-ments of the National Institutes of Health under a study cooperative agreement (U01-DK-098245, principal investigator A.G.P.). The study also received secondary funding from the American Diabetes Association (1-14-D2d-01, principal investigator A.G.P.). Educational materials were provided by the National Diabetes Education Program. B.D.-H. is supported by U01-DK-098245 and the U.S. Department of Agriculture under agreement No. 58-1950-0-014. A.G.P. is supported in part by generous donations to the Tupper Research Fund at Tufts Medical Center. Any opinions, findings, conclusions, or recom-mendations expressed in this publication are those of the authors and do not necessarily reflect the view of the National Institutes of Health or the U.S. Department of Agriculture. Funding Information: The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (the study{\textquoteright}s primary funding agency) has established central biosample, genetic, and data repositories for the archival and storage of data and biosamples collected in large, multisite studies funded by NIDDK (such as D2d). The study{\textquoteright}s co-ordinating center will coordinate with the NIDDK data repository to prepare the collected data and samples for eventual archiving to the repositories. All samples and data transferred to the repositories will be under the custodianship of the NIDDK and will become available to the public in accordance with standard NIDDK policies. Publisher Copyright: {\textcopyright} 2020 by the American Diabetes Association.",
year = "2020",
month = dec,
doi = "10.2337/dc20-1765",
language = "English (US)",
volume = "43",
pages = "2916--2922",
journal = "Diabetes Care",
issn = "1935-5548",
publisher = "American Diabetes Association Inc.",
number = "12",
}
