First to understand the claim that Vitamin D increases testosterone in men, we need to understand what Vitamin D and Testosterone are.
Vitamin D is very important for your good overall health and strong and healthy bones, mainly Vitamin D is made by your skin when it is exposed to sunlight, and a very small amount of it can be brought in to your body through some foods. When your body makes Vitamin D it has to be changed a number of times before it can be used to manage the levels of calcium in your blood, in your bones, for which calcium is very beneficial as it helps grow bones and makes them stronger. Vitamin D also helps in communication of different cells in your body. And also there was that recent study that suggests that Vitamin D also increases testosterone levels in your body.
Testosterone is a steroid hormone. In men, testosterone influence the development of the male reproductive tissues, like prostate and testis, as well as helping secondary sexual characteristics, increased bone and muscle mass and growth of new body hair. It is especially important in puberty where most of these changes start occurring for the first time. Testosterone is also important for your overall health and prevention of osteoporosis. It is usually referred to as the male hormone, but not many people know that females also have testosterone although in much smaller quantities, men have 8 times as much testosterone as women. Also it is known that females are much more sensitive to this hormone than men, which may explain why they have so little of it compared to men.
Now that we know what Vitamin D and testosterone are, let’s talk about that study that says vitamin D improves testosterone. This was a study in Germany which was looking at how vitamin D can effect weight loss. Two hundred random overweight but otherwise healthy individuals were chosen for this weight loss study. Half of the participants were receiving vitamin D at the dose of 3,333 IU a day for 12 months, while other half received placebo pills. In this study there were 54 men in total, 31 received the vitamin D and 23 received placebo, after the study was done extensive laboratory tests for testosterone were performed. In all of the men who were taking vitamin D every day, there was a noticeable increase in the total testosterone level, in average they rose from 10.4 nmol/litre to 13.4 nmol/litre after 12 months. And the same was true for bioavailable-testosterone and free testosterone levels. Total testosterone refers to testosterone bound to the blood proteins and the free testosterone. Free testosterone refers to testosterone that is not bound to any proteins. And bioavailable testosterone refers to free the testosterone and testosterone loose bound to albumin. There were experiments done on mice which also suggest that an increase in vitamin D also led to an increase to the testosterone levels. Also it has been found that testicles have the receptors for vitamin D, which suggest that vitamin D plays some role there. So yes, it could be true that vitamin d improves testosterone.