Vitamin D supplementation vs. placebo and incident type 2 diabetes in an ancillary study of the randomized Vitamin D and Omega-3 Trial
Year: 2025
Type: article
Abstract: Observational and experimental evidence suggests that vitamin D plays a role in type 2 diabetes (T2D). However, prior randomized supplementation trials are limited to high-risk patients with prediabetes. Here we aim to evaluate whether vitamin D supplementation reduces risk of T2D in a general population of older US adults. The study design is an ancillary analysis (VITAL-T2D) of The Vitamin D and Omega-3 Trial (VITAL), a completed randomized, double-blind, placebo-controlled 2 × 2 trial of daily vitamin D3 (cholecalciferol; 2000 IU/day) and omega-3 fatty acids (1 g/day) for the primary prevention of cancer and cardiovascular disease. We also conducted a systematic review and meta-analysis of vitamin D trial (≥1000 IU/d cholecalciferol) vs. placebo and T2D risk. We analyzed 22,220 adults with mean age 67.2 years (SD = 7.1) without T2D at enrollment (2011 to 2014), randomized to vitamin D3 or placebo. Mean body mass index (BMI) was 27.5 kg/m2 (SD = 5.3), with 51% female and 17% Black race/ethnicity. A subcohort (n = 911) attended in-person visits at baseline and 2 years for glycemic trait analyses. Our meta-analysis included 3 additional trials (5205 participants; 936 T2D cases). The primary outcome for the VITAL-T2D is intention-to-treat effect of vitamin D vs. placebo for incident T2D. T2D incidence (cases/1000py) at median follow-up of 5.3 y was 3.98 for vitamin D and 4.37 for placebo (hazard ratio [HR] = 0.91; 95% confidence interval [CI] = 0.76, 1.09). Results did not differ by age, sex, BMI, or baseline 25-hydroxyvitamin D, and vitamin D had no effect on glycemic traits at 2 years. Meta-analysis of 4 trials (n = 5205; 936 T2D cases) obtained HR = 0.89 (CI = 0.80, 0.99). In conclusion, Vitamin D supplementation did not reduce T2D in older US adults, but a modest reduction was observed when meta-analyzed with prior trials. Trial Registration: ClinicalTrials.gov #NCT01633177. Systematic Review Registration: PROSPERO #CRD42019147562. Observational and experimental evidence suggests that vitamin D plays a role in glycemic control. Here, the authors report that in an ancillary study of the placebo-controlled randomized VITAL trial there is no effect of 2000 IU/day of vitamin D supplementation over 5 years on the prevention of type 2 diabetes in 22,220 older US adults.
Source: Nature Communications
Language: English
Topic: Vitamin D Research Studies
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: Office of Dietary Supplements, Pharmavite, Harvard Catalyst, Quest Diagnostics, National Institutes of Health, Centers for Disease Control and Prevention, National Heart, Lung, and Blood Institute, National Institute of Mental Health, National Cancer Institute, National Institute of Diabetes and Digestive and Kidney Diseases, National Center for Research Resources, National Center for Complementary and Integrative Health
Awards: G1763823711, G2496518617, Harvard Clinical and Translational Science Center (UL1), G3615943839, Diabetes Prevention in the Vitamin D and Omega-3 Trial, VITamin D and omegA-3 triaL (VITAL), G6859357459, Harvard Clinical and Translational Science Center (UL1), Harvard Clinical and Translational Science Center, The VITamin D and OmegA-3 TriaL (VITAL), UCSD Future Faculty of Cardiovascular Sciences (FOCUS), The VITamin D and OmegA-3 TriaL (VITAL): Post-Intervention Follow-Up, Circulating plasma metabolites, diet, and risk of type 2 diabetes
OpenAlex ID: W4409246737