Vitamin D and Testosterone: What’s the Link?

Although most people know vitamin D as the “sunshine vitamin” that benefits bone health and mood, it’s also a vital component of hormone and reproductive health. However, because of less time spent in the sun, increased sunscreen usage, and reduced dietary intake, many people now find themselves with a deficient or inadequate vitamin D status.  

While few men attribute their reproductive health and testosterone levels to vitamin D, increasing deficiencies in the vitamin may be one missing link in the explanation for why male infertility is simultaneously rising. In a study published in the Asian Journal of Andrology, researchers from the University of Sao Paulo in Brazil revealed more about the relationship between vitamin D, testosterone, and sperm quality—let’s take a closer look at what they found. 

How Does Vitamin D Impact Testosterone?  

Studies have shown that vitamin D helps regulate testosterone production. As vitamin D receptors are found in the cells of the testes (where testosterone is produced), this suggests that vitamin D is involved in testosterone synthesis. The enzyme needed to convert vitamin D into its active form has also been detected in cells of the male reproductive system.  

Previous research has found that vitamin D deficiencies are associated with alterations in various hormone levels, including testosterone. Although many people only associate testosterone with sexual health, the androgen hormone is also vital for muscle and bone strength, cardiovascular health, and red blood cell production.  

In addition to supporting testosterone levels in males, healthy vitamin D levels have also been reported to improve aspects of male fertility, such as sperm motility and morphology (the size, shape, and appearance of the sperm).  

Higher Vitamin D Linked to Better Male Reproductive Health 

In this study, the researchers divided 260 Brazilian adult males into two groups: a “normozoospermic” group with normal and healthy sperm and a group with seminal or sperm abnormalities.  

The group with seminal abnormalities—which could include decreases in sperm motility or abnormal morphology—had significantly lower serum vitamin D levels than the normal sperm group. One-third of men in the abnormal sperm group had vitamin D deficiency, compared to one-quarter of the normal group.  

Regarding sperm quality, the best sperm parameters were found in men with healthy serum vitamin D levels (30 to 40 ng/mL). Similarly, higher vitamin D levels correlated with better sperm concentration, sperm motility, total number of motile sperm, and sperm morphology.  

The researchers calculated that each 1-unit increase in serum vitamin D levels was associated with a 2.1% increase in progressive motility of the spermatozoa—one of the most important indicators of healthy sperm and male fertility.  

All in all, this study shows clear associations between healthy vitamin D status, testosterone levels, and sperm quality, which all play a role in male reproductive and sexual health. 

How to Support Healthy Testosterone and Vitamin D 

There are several ways to support healthy vitamin D levels, which can then boost testosterone and sperm quality.* 

The best way to raise vitamin D levels is through moderate sun exposure (being careful to avoid sunburns). If you don’t see the sun often or live in a more northern latitude, vitamin D supplements are generally a low-risk way to support your vitamin D status.* 

Consider a supplement that combines vitamin D3 with vitamin K2 to support bone health and mineralization. However, you can take too much vitamin D, so it’s essential to get your serum vitamin D levels checked regularly to ensure you aren’t raising your levels excessively. * 

Other ways to support healthy testosterone levels include: 

• Not smoking 

• Getting enough quality sleep 

• Limiting alcohol  

• Avoiding endocrine disruptors (like BPA, pesticides, and other pollutants) 

• Regular exercise (both aerobic and strength training) 

• Zinc-rich foods like oysters, shellfish, and red meat 

• Foods high in omega-3 fats, like fatty fish and flaxseed 

• Selenium-rich foods like Brazil nuts 

• Consider supplements like ashwagandha or magnesium  

Key Takeaways 

Testosterone is a vital hormone for male health, including reproduction and fertility. Research has suggested that increased rates of vitamin D deficiency may be a missing link to explain the similarly rising rates of male infertility. 

In this study, Brazilian researchers found that men with abnormal sperm parameters were much more likely to be vitamin D deficient than men with normal sperm. Higher vitamin D levels were significantly associated with higher testosterone levels and better sperm quality, motility, and morphology. 

Support healthy testosterone and sperm by ensuring adequate vitamin D status and eating foods rich in zinc, magnesium, selenium, and omega-3 fats. Other healthy habits that support testosterone include limiting alcohol, exercising regularly, getting enough sleep, and maintaining a healthy body weight.*  

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* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. 

 

References: 

Blomberg Jensen M. (2014). Vitamin D and male reproduction. Nature reviews. Endocrinology, 10(3), 175–186. https://doi.org/10.1038/nrendo.2013.262  

Blomberg Jensen, M., Nielsen, J. E., Jørgensen, A., Rajpert-De Meyts, E., Kristensen, D. M., Jørgensen, N., Skakkebaek, N. E., Juul, A., & Leffers, H. (2010). Vitamin D receptor and vitamin D metabolizing enzymes are expressed in the human male reproductive tract. Human reproduction (Oxford, England), 25(5), 1303–1311. https://doi.org/10.1093/humrep/deq024  

Chin, K. Y., Ima-Nirwana, S., & Wan Ngah, W. Z. (2015). Vitamin D is significantly associated with total testosterone and sex hormone-binding globulin in Malaysian men. The aging male: the official journal of the International Society for the Study of the Aging Male, 18(3), 175–179. https://doi.org/10.3109/13685538.2015.1034686  

Ciccone, I. M., Costa, E. M., Pariz, J. R., Teixeira, T. A., Drevet, J. R., Gharagozloo, P., Aitken, R. J., & Hallak, J. (2021). Serum vitamin D content is associated with semen parameters and serum testosterone levels in men. Asian Journal of Andrology, 23(1), 52-58. https://doi.org/10.4103/aja.aja_9_20  

Cinar, V., Polat, Y., Baltaci, A. K., & Mogulkoc, R. (2011). Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion. Biological trace element research, 140(1), 18–23. https://doi.org/10.1007/s12011-010-8676-3  

Lopresti, A. L., Drummond, P. D., & Smith, S. J. (2019). A Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha ( Withania somnifera) in Aging, Overweight Males. American journal of men's health, 13(2), 1557988319835985. https://doi.org/10.1177/1557988319835985  

Prasad, A. S., Mantzoros, C. S., Beck, F. W., Hess, J. W., & Brewer, G. J. (1996). Zinc status and serum testosterone levels of healthy adults. Nutrition, 12(5), 344–348. https://doi.org/10.1016/s0899-9007(96)80058-x  

Safarinejad MR, Safarinejad S. Efficacy of selenium and/or N-acetyl-cysteine for improving semen parameters in infertile men: a double-blind, placebo-controlled, randomized study. J Urol. 2009;181(2):741-751. doi:10.1016/j.juro.2008.10.015   

Tania, C., Tobing, E. R. P. L., Tansol, C., Prasetiyo, P. D., Wallad, C. K., & Hariyanto, T. I. (2023). Vitamin D supplementation for improving sperm parameters in infertile men: A systematic review and meta-analysis of randomized clinical trials. Arab journal of urology, 21(4), 204–212. https://doi.org/10.1080/2090598X.2023.2165232