Will a vitamin D supplement boost my testosterone?
Does Vitamin D Raise Testosterone? A 2026 Meta-Analysis of Randomised Trials
· By Anthony Falcone
Verdict: Drop it. Probably not. Pooling 11 trial comparisons with 703 men, vitamin D made no clear difference to testosterone or related markers. The authors say the open question is men who are both vitamin D deficient and low in testosterone; that's where future trials should look.
What the researchers tested
Vitamin D is often sold as a testosterone booster, mostly because men with low vitamin D levels in surveys also tend to have lower testosterone. Surveys can't show cause and effect, though: body fat, activity, time outdoors and general health affect both.
So this team gathered randomised trials in which adult men took vitamin D or a control, and pooled the hormone results: total testosterone, SHBG (the protein that binds testosterone in the blood), the free androgen index, calculated free testosterone and bioactive testosterone.
They screened 2,151 records. Eleven trial comparisons had usable total testosterone data for the main analysis.
What they found
Total testosterone ended up 0.47 nmol/L higher with vitamin D on average, but the range of plausible effects ran from slightly lower to slightly higher (−0.50 to 1.44 nmol/L), so the result isn't statistically clear.
SHBG, the free androgen index, calculated free testosterone and bioactive testosterone also showed no clear change.
One extra check did show a small rise: after removing the heart-failure and dialysis groups, testosterone came out about 1 nmol/L higher. The authors warn against reading much into it, because removing the athlete studies or the studies with other interventions (such as weight loss or training) pulled the effect back towards zero.
The authors rated the certainty of the evidence as low for total testosterone, SHBG and the free androgen index, and very low for the free and bioactive testosterone markers.
What this means for you
- Don't buy vitamin D to raise your testosterone — the trials so far don't show it doing that.
- That's a different question from whether you need vitamin D at all. Its established role, as the paper notes, is calcium balance and bone health.
- If you think your testosterone is low, a morning blood test and a conversation with your doctor will tell you more than any supplement experiment.
How much to trust it
- The authors' own: Embase wasn't searched, 27 reports couldn't be assessed because the full text wasn't obtained, and several trials couldn't be pooled because of missing or inconsistent data.
- Most trials measured testosterone as a side outcome, not the main one, and only 1 of the 11 comparisons was judged at low risk of bias.
- The men were very mixed — from elite athletes to men on dialysis — and doses, durations and starting vitamin D levels varied.
- Few studies per outcome; the free and bioactive testosterone results rest on only two or three trials each.
The study
Paez-Allendes L, Valenzuela-Fuenzalida JJ, Moya MP, Oyanedel G, 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.org/10.3390/nu18132090
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