Does vitamin D raise testosterone? What the research does and doesn't show

Vitamin D supplements have not been shown to raise testosterone. A 2019 meta-analysis of eight trials in men found no significant effect on total testosterone, and a 2026 meta-analysis of 11 comparisons found none either (mean difference 0.47 nmol/L, 95% CI -0.50 to 1.44), with low certainty.

What the evidence doesn't support

• Vitamin D3 as a testosterone booster. Neither pooled analysis of randomised trials found a significant effect on total testosterone.
• An effect on free testosterone or related markers. The 2026 analysis found no clear effect on SHBG, free androgen index, calculated free testosterone or bioactive testosterone.
• A dose that raises testosterone. The trials covered 600 to 4,000 IU a day and up to 60,000 IU a week, and found no effect when split by duration or by daily versus weekly dosing.
• Vitamin D for erectile function. We found no trial to cite, so no statement is made.
• No evidence for use in low testosterone. That is a medical diagnosis made by blood tests and a clinician, and a vitamin is not a substitute for one.

What the trials found

2019: eight trials, no effect

A 2019 systematic review and meta-analysis in Andrologia pooled randomised controlled trials of vitamin D supplementation in men aged 18 and over: eight studies, 10 effect sizes. Daily-dose equivalents ranged from 600 to 4,000 IU a day up to 60,000 IU a week, and trials lasted from 6 weeks to 36 months. Vitamin D had no significant effect on total testosterone (mean difference 0.20, 95% CI -0.20 to 0.60) or on sex hormone-binding globulin (1.56, 95% CI -0.85 to 3.97). Subgroups by duration, daily or weekly dosing, and baseline vitamin D or testosterone did not change the conclusion. The authors found no evidence of a beneficial effect and called for large randomised trials. Certainty: not graded in the abstract; the number of trials was small.

2026: eleven comparisons, still no clear effect

A 2026 systematic review and meta-analysis in Nutrients searched to April 2026 and pooled 11 comparisons for final total testosterone. It found no clear effect (mean difference 0.47 nmol/L, 95% CI -0.50 to 1.44; I2 24%), and none for SHBG (0.27 nmol/L, 95% CI -2.14 to 2.68), the free androgen index, calculated free testosterone or bioactive testosterone. GRADE certainty was low for total testosterone, SHBG and the free androgen index, and very low for the other two. The authors concluded randomised evidence does not demonstrate a reproducible effect. It is one more analysis pointing the same way, and its low certainty means a larger trial could still change the picture.

Analysis	Who	Total testosterone
Andrologia 2019, 8 trials	Men 18+, 600-4,000 IU/day to 60,000 IU/week	No significant effect (MD 0.20, -0.20 to 0.60)
Nutrients 2026, 11 comparisons	Adult men	No clear effect (MD 0.47 nmol/L, -0.50 to 1.44); low certainty

Questions people ask

Does vitamin D3 help with testosterone?

Pooled randomised trials say it has not been shown to. Two meta-analyses, in 2019 and 2026, found no significant effect on total testosterone in men.

Is vitamin D3 good for testosterone, or does it increase it?

The same answer: not by the trial evidence. Observational studies link vitamin D levels and testosterone, but the supplement trials did not find that raising vitamin D raised testosterone. We cite no evidence that it does.

Does vitamin D3 with K2 help testosterone?

We found no trial of the pair to cite. Vitamin K2 is a separate vitamin; no claim is made for the combination.

Does vitamin D3 help erectile dysfunction?

We found no trial to cite, so we say nothing about it. Erection problems can reflect many conditions, including heart and blood-vessel disease, and are worth raising with a doctor.

How much vitamin D3 should men take?

The RDA and the upper limit are the same for adult men and women: 600 IU (15 mcg) to age 70, 800 IU (20 mcg) over 70, and a limit of 4,000 IU (100 mcg) from all sources (NIH Office of Dietary Supplements). See how much vitamin D should you take a day and what vitamin D does for men.

When to talk to a doctor

Low energy, low sex drive, or erection problems are reasons to see a doctor, who can check testosterone with blood tests at the right time of day and look for causes. Vitamin D is not a treatment for low testosterone or any other condition, and nothing above supports using it in place of care. If you take medication, or have a condition affecting calcium or the kidneys, ask a doctor before adding a supplement.