Meta-analyses of randomized trials disagree on whether vitamin D supplements raise testosterone. Two found no clear effect, one found a small increase in total testosterone. The certainty is low. If you are deficient, treat that for your health, but do not expect a testosterone boost.
What the reviews found
| Review | What it pooled | Result for total testosterone |
|---|---|---|
| Marnani et al., 2019 | 8 randomized trials in men | No significant effect. Subgroups by dose, duration, and baseline vitamin D also showed no effect. |
| Alomar et al., 2024 | 17 randomized trials in adult men | A small increase in total testosterone, with large differences between trials. No effect on free testosterone. |
| Paez-Allendes et al., 2026 | 11 comparisons from randomized trials | No clear effect (mean difference 0.47 nmol/L, confidence interval -0.50 to 1.44). Certainty rated low. |
How to read conflicting reviews
When reviews of the same question disagree, the usual explanation is that the underlying trials are small and varied: different doses, different durations, different starting vitamin D levels. The most recent review rated the certainty of the evidence as low, which fits that picture. The honest summary is that a testosterone benefit has not been shown reliably.
What to do with this
- Vitamin D matters for bone and general health. If you may be low, a blood test tells you whether you need to supplement.
- If you are not deficient, taking more is unlikely to move your testosterone.
- Choose products that are third-party tested, and ask your clinician about a dose that is right for you.
Sources
- Hosseini Marnani E, Mollahosseini M, Gheflati A, et al. The effect of vitamin D supplementation on the androgenic profile in men: a systematic review and meta-analysis of clinical trials. Andrologia 2019;51(9):e13343
- Alomar O, Baradwan S, Saleh SAK, et al. The impact of vitamin D on androgens and anabolic steroids among adult males: a meta-analytic review. Diseases 2024;12(10)
- Paez-Allendes L, Valenzuela-Fuenzalida JJ, et al. Vitamin D supplementation, total testosterone, and androgen bioavailability markers in adult men: a systematic review and meta-analysis of randomized controlled trials. Nutrients 2026 (DOI 10.3390/nu18132090)
This article is general education, not medical advice. Talk to a clinician about testing and treatment. Medical disclaimer.