Vitamin D supplementation for prevention of type 2 diabetes mellitus. To D or not to D?

Authors: PITTAS, ANASTASSIOS - Tufts Medical Center; JORDE, ROLF - The University Of Tromsø; KAWAHARA, TETSUYA - Kokura Medical Association Health Testing Center; DAWSON-HUGHES, BESS - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Journal of Clinical Endocrinology and Metabolism
Publication Type: Review Article
Publication Acceptance Date: 8/14/2020
Publication Date: 8/26/2020
Citation: Pittas, A.G., Jorde, R., Kawahara, T., Dawson-Hughes, B. 2020. Vitamin D supplementation for prevention of type 2 diabetes mellitus. To D or not to D? Journal of Clinical Endocrinology and Metabolism. 105(12):3721-3733. https://doi.org/10.1210/clinem/dgaa594.
DOI: https://doi.org/10.1210/clinem/dgaa594

Interpretive Summary:

Technical Abstract: Context: Over the last decade, vitamin D has emerged as a risk determinant for type 2 diabetes and vitamin D supplementation has been hypothesized as a potential intervention to lower diabetes risk. Recently, several trials have reported on the effect of vitamin D supplementation on diabetes prevention in people with prediabetes. Evidence Acquisition: A comprehensive literature review was performed using PubMed, Embase, and ClinicalTrials.gov to identify: 1) recent meta-analyses of longitudinal observational studies that report on the association between blood 25(OH)D level and incident diabetes and 2) clinical trials of adults with prediabetes that have reported on the effect of vitamin D supplementation on incident diabetes. Evidence Synthesis: Longitudinal observational studies report highly consistent associations between higher blood 25(OH)D levels and lower risk of incident diabetes in diverse populations, including populations with prediabetes. Trials in persons with prediabetes show risk reduction in new-onset diabetes with vitamin D supplementation. In the three large trials that were specifically designed and conducted for prevention of diabetes, vitamin D supplementation when compared with placebo, reduced risk of diabetes by 10 to 13% in persons with prediabetes not selected for vitamin D deficiency. Conclusions: Results from recent trials are congruent with a large body of evidence from observational studies indicating that vitamin D has a role in modulating diabetes risk. Participant-level meta-analysis of the three largest trials should provide a more refined estimate of risk reduction and may identify patient populations likely to benefit the most.