The effect of vitamin D supplementation on the androgenic profile in men: A systematic review and meta-analysis of clinical trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 31332821 · doi:10.1111/and.13343
What was done
Researchers performed a systematic review and meta-analysis of randomized controlled trials indexed in PubMed, Scopus, and Web of Science through September 2018. They evaluated the effect of vitamin D supplementation on total testosterone (TT) and sex hormone-binding globulin (SHBG) in men aged 18 years and older. A random-effects model was used to pool data across 8 included studies representing 10 effect sizes. Intervention regimens ranged from 600 to 4,000 IU daily or up to 60,000 IU weekly, with durations ranging from 6 weeks to 36 months.
What was found
Vitamin D supplementation showed no statistically significant effect on total testosterone (mean difference = 0.20, 95% CI: -0.20 to 0.60, p = 0.336) or on sex hormone-binding globulin (mean difference = 1.56, 95% CI: -0.85 to 3.97, p = 0.204). Subgroup analyses stratified by prescription duration, dosing schedule (daily vs weekly), dosing frequency, baseline vitamin D status, and baseline total testosterone concentration also showed no significant effect on total testosterone.
Why it matters
This review aggregates randomized trial evidence indicating that vitamin D supplementation does not meaningfully raise testosterone or alter SHBG in adult men, countering claims that vitamin D acts as an androgen-enhancing supplement.
Limits
The meta-analysis included a small number of studies (8 trials), and the total participant count was not reported in the abstract. Dosing schedules and durations were highly heterogeneous, and the abstract did not evaluate free testosterone, clinical androgen deficiency symptoms, or safety outcomes.
Cited by
- contradicts Deficiencies in zinc, magnesium, or vitamin D can cause a deterioration in testosterone levels of over 100 ng/dL depending on severity.