Vitamin D and Testosterone in Healthy Men: A Randomized Controlled Trial

Study answer

What this study found

Vitamin D supplementation did not increase total testosterone in healthy men. In the vitamin D group, total testosterone changed from 18.7 to 19.4 nmol/L (change 0.5; within-group P=0.497), and the between-group difference was not significant (P=0.922). Vitamin D status improved substantially, with 25(OH)D rising from 52 to 107 nmol/L by study end (P=0.001). Overall, the trial found no clear testosterone benefit from vitamin D in this cohort, although other endocrine and insulin-sensitivity changes were reported in the broader paper.

Study & population

Randomized, double-blind, placebo-controlled, single-center trial at the Medical University of Graz, Austria.

Intervention

Vitamin D3 (Oleovit D3 drops), 20,000 IU orally once weekly for 12 weeks, equivalent to about 2,857 IU/day.

Key limitation

Small, single-center study in healthy men, which limits generalizability.

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Original abstract