Vitamin D Supplementation and Prevention of Type 2 Diabetes

This multicenter, randomized, placebo controlled trial investigated whether vitamin D₃ supplementation (4000 IU/day) could prevent type 2 diabetes in 2423 high risk adults with prediabetes. Over a median follow up of 2.5 years, diabetes developed in 293 participants in the vitamin D group and 323 in the placebo group (hazard ratio, 0.88; 95% CI, 0.75–1.04; P=0.12). While vitamin D increased serum 25 hydroxyvitamin D levels significantly (54.3 ng/mL vs. 28.8 ng/mL in placebo), it did not significantly reduce diabetes risk. Subgroup analyses suggested a potential benefit in participants with severe baseline vitamin D deficiency (<12 ng/mL; hazard ratio, 0.38). Safety outcomes were similar between groups. The study concluded that vitamin D supplementation did not significantly lower diabetes incidence in this population.

This multicenter, randomized, placebo controlled trial investigated whether vitamin D₃ supplementation (4000 IU/day) could prevent type 2 diabetes in 2423 high risk adults with prediabetes. Over a median follow up of 2.5 years, diabetes developed in 293 participants in the vitamin D group and 323 in the placebo group (hazard ratio, 0.88; 95% CI, 0.75–1.04; P=0.12). While vitamin D increased serum 25 hydroxyvitamin D levels significantly (54.3 ng/mL vs. 28.8 ng/mL in placebo), it did not significantly reduce diabetes risk. Subgroup analyses suggested a potential benefit in participants with severe baseline vitamin D deficiency (<12 ng/mL; hazard ratio, 0.38). Safety outcomes were similar between groups. The study concluded that vitamin D supplementation did not significantly lower diabetes incidence in this population.