Differences in HOMA and insulin levels following vitamin D supplementation in healthy† men: A randomized double blind controlled trial
Diabetes, Obesity and Metabolism 2016 Vol. 18 Issue 3
Vitamin D is thought to play a role in glucose metabolism.The study objective was to determine the effect of vitamin D supplementation on markers of insulin sensitivity and inflammation in non-diabetic men with vitamin D deficiency/insufficiency. In this one-year randomized double-blind controlled trial, 130 men aged 20-65 (47.52 ± 11.84 ) with 25(OH)Dserum levels <20 (15.58 ± 3.46) ng/mL were randomized to treatment (100,000IU vitamin D bimonthly) or placebo. Anthropometric measurements, demographic questionnaires, and blood indices (Fasting glucose, insulin, hs-CRP, lipids) were collected and repeated after 6 and 12 months.
Adherence rate was 98.5%, Multivariate models, adjusted for baseline levels, age, BMI, sun exposure, physical activity, and LDL, demonstrated significant differences of insulin and HOMA-IR between groups. Levels of insulin and HOMA-IR remained steady along the study period in the treatment group but increased by 16% in the control.(p=0.038, p=0.048 respectively).
Vitamin D supplementation administered for 12 months for healthy men maintained insulin and HOMA-IR levels relative to the increase in the control group. Further studies are needed to establish the long-term effect of vitamin D supplementation on the risk of diabetes.