It might be hard to believe in Australia, but at least 30% of adults have a Vitamin D deficiency in this country – in spite of all the sunshine. The rates are even higher in young adults who have grown up fearing the sun thanks to the extreme anti-sun messages put out by the Skin Cancer Council. What nutritionists all over Australia have been quietly saying for years is now gaining momentum – we badly need to increase our Vitamin D intake for a range of very important health reasons. Vitamin D which we synthesise from sun exposure most efficiently is paramount in growing strong bones and having healthy organs – and – having healthy testosterone levels. But our indoor working lives, growing car use and worries about skin damage mean we are looking more and more at oral supplementation of Vitamin D. So what about Vitamin D and testosterone production?
For men, vitamin D assists in ideal testosterone levels for sexual health and weight control. For example, a recent study followed 2,069 men over three years found that men with a higher vitamin D standing had higher free testosterone. Men who were deficient in vitamin D and testosterone had a 111 percent increase in all-cause mortality over the course of the study . From looking at over a dozen studies, we can say that Vitamin D really only boosts testosterone levels IF the man is deficient in Vitamin D and had poor testosterone levels – which significantly – more and more men do unfortunately have. A couple of studies have shown no increase in testosterone with an increase in Vitamin D and another study with bodybuilders showed that their strength did not increase with Vitamin D supplementation. But this is not surprising in healthy trained men and those negative outcomes in those studies should not discount Vitamin D as a key ingredient.
Our Verdict: Recommended
Vitamin D scores moderately well from us. It does not get a higher score because there is still some research needed to determine just who can benefit most from taking it as a supplement with regard solely to increasing testosterone. But it becomes extremely important if you have a deficiency. As for dosing, the regimen is clear. A daily dose of 2,000 to 5,000 IUs depending on just how much sun you get or a single weekly large dose of up to 35,000 IUs has been effective to maintaining vitamin D above the optimal 40 ng/ml range.
 Lerchbaum, E., et al. Combination of Low Free Testosterone and Low Vitamin D Predicts Mortality in Older Men, Coronary Angiography. Clinical Endocrinology. 2012. 77, 475-483.
 See for example: Nimptsch K1, Platz EA, Willett WC, Giovannucci E.Clin Endocrinol (Oxf). Association between plasma 25-OH vitamin D and testosterone levels in men. Jul 2012; 77(1): 106–112.
 For example, see: Jordy, R. Supplementation with vitamin d does not increase serum testosterone levels in healthy males.Horm Metab Res. 2013 Sep;45(9):675-81.