Vitamin D (cholecalciferol, D3)
What it is
Steroid hormone precursor; vitamin D receptors are expressed in testicular and pituitary tissue, suggesting a permissive role in androgen production.
What the evidence says
Evidence is mixed but leans toward a small benefit only with correction of deficiency. A 2024 meta-analysis of 17 RCTs (1,774 men) found vitamin D significantly raised total testosterone (WMD 0.38), but with substantial heterogeneity, no effect on free testosterone, SHBG, or estradiol, and larger effects only above 4,000 IU/day for over 12 weeks. An earlier 2019 meta-analysis found no significant effect. Benefit appears confined to deficient or older men, not those already replete.
Correct deficiency to a serum 25(OH)D of ~30 ng/mL; trials showing effects used roughly 3,000-5,000 IU/day for 12+ weeks. NIH RDA is 600-800 IU/day; tolerable upper limit 4,000 IU/day for adults.
Educational summary of doses studied — not a recommendation. Talk to a clinician before starting any supplement.
Sources (2)
- The Impact of Vitamin D on Androgens and Anabolic Steroids among Adult Males: A Meta-Analytic Review — Diseases, 12(10):228 (PMC11506788) (2024)
- Vitamin D - Health Professional Fact Sheet — NIH Office of Dietary Supplements (2024)
Educational summary of published research, checked against primary sources and linked inline. Not medical advice; supplements are not FDA-evaluated to treat disease. See our editorial policy.