There’s been a lot of research analyzing the link between vitamin D and testosterone production, and the findings are really interesting. But since tracking down all this research can be time-consuming, I thought I’d put together a brief article highlighting what we know so far.
So what exactly does vitamin D have to do with testosterone, and is it really a testosterone boosting supplement? Mainly, vitamin D inhibits a process known as aromatization, where testosterone is changed into estrogen.
There’s also data showing that vitamin D may enhance cell receptor sensitivity in the testicles where testosterone is produced.
One study in 2008 showed that the risk of falls in the elderly was reduced more in individuals with increased testosterone, vitamin D, and calcium, compared to only elevated testosterone levels. This suggests that a synergistic relationship exists between testosterone and vitamin D.
A study in 2010 indicated that men with sufficient vitamin D levels had significantly higher levels of free testosterone and free androgen index (FAI), and lower levels of sex hormone binding globulin (SHBG) when compared to men with insufficient or deficient vitamin D.
Interestingly, this study also showed that testosterone levels follow a seasonal pattern, peaking in August and being at lowest levels in March.
Another study conducted in 2011 demonstrated that men who supplemented vitamin D had significant increases in total testosterone, bioactive testosterone, and free testosterone when compared to baseline. However, those who did not supplement with vitamin D did not show significant increases in any of those levels.
Many of the studies conducted were looking at people who already had a vitamin D deficiency for one reason or another. Like most vitamins and health supplements, there is almost certainly a point of diminishing returns at which the benefits subside.
How Much Vitamin D Do You Need?
According to the National Institute of Health, 600 IU’s per day is recommended for those over the age of 18, and for those over the age of 70, 800 IU’s per day. If you are in a high-risk deficiency group you may need to take more – one of the studies mentioned above had the participants taking 3,000 IU’s per day.
Those who may be at risk of being vitamin D deficient include those suffering from chronic disease (such as kidney disease) and those who live in colder climates. Basically, the farther you live from the equator, the greater your risk for vitamin D deficiency.
Sources of Vitamin D
The best (and cheapest) source of vitamin D is exposure to sunlight. 30 minutes a day between the hours of 10 AM and 2 PM is enough for most.
Besides sunlight, there’s plenty of dietary sources to choose from, including fatty fish (such as salmon, tuna, and mackerel), liver, eggs, cheese, and foods that have vitamin D added, such as milk, orange juice, and breakfast cereals.
Supplements are probably the easiest way to ensure you’re getting plenty of vitamin D. Fish oil is not only packed with vitamin D, but also rich in omega-3 fatty acids. And many good multivitamins for men and workout supplements will also contain plenty of vitamin D.
As far as vitamin D’s impact on testosterone, it’s pretty clear that men who are deficient in vitamin D show an increase in testosterone after they begin supplementation. Whether or not the same results occur in men with already normal levels of vitamin D is unclear at this point.
Fortunately, taking vitamin D supplements causes very few, if any, side effects, especially if taking the recommended daily allowance. Because of the important benefits, all men should include adequate amounts of vitamin D as part of their health supplement regimen.
Additive benefit of higher testosterone levels and vitamin D plus calcium supplementation in regard to fall risk reduction among older men and women. Osteoporosis International (2008), Bischoff-Ferrari et al.
Association of vitamin D status with serum androgen levels in men. Clinical Endocrinology (2010), Wehr et al.
Effect of vitamin D supplementation on testosterone levels in men. Hormone and Metabolic Research (2011). Pilz et al.
Supplementation with vitamin D does not increase serum testosterone levels in healthy males. Hormone and Metabolic Research (2013). Jorde et al.