Vitamin D is one of the 24 essential vitamins necessary for our survival. It regulates over 1,000 bodily functions. It is a fat-soluble vitamin, which means it is absorbed through the small intestine with dietary fats and stored in body tissues. Unlike water-soluble vitamins, it is stored in the body longer, so high doses of Vitamin D can prove toxic.
Vitamin D occurs naturally in eggs and fish; however, the best way to get it is through sun exposure. It is known as a “wonder vitamin” because of its various health benefits. In fact, it is one of the best vitamins a man can take. Vitamin D performs many essential tasks, from keeping your heart healthy to making your bones stronger. It can also act as a potent testosterone booster. Let us see how Vitamin D levels may impact testosterone levels, and what research says on this.
Vitamin D and Testosterone Levels
Vitamin D is a highly researched nutrient, and various studies have been conducted to understand the relation between Vitamin D3 and testosterone levels. Here is a summary of some of these studies.
Study: Association between plasma 25-OH vitamin D and testosterone levels in men
1362 male participants were selected to study the association between plasma 25-hydroxyvitamin D [25(OH)D] and testosterone levels.
- 25(OH)D was positively associated with free and total testosterone levels
- There were no parallel seasonal variation patterns
Study: Association of vitamin D status with serum androgen levels in men.
In this study, 2299 men who were referred for coronary angiography were tested for 25(OH)D, SHBG and testosterone levels.
Men with sufficient 25(OH)D levels (> or =30 microg/l) had significantly higher testosterone and FAI levels and lower SHBG levels when compared to men with insufficient 25(OH)D (20-29.9 microg/l) levels and deficient 25(OH)D (<20 microg/l) levels.
Study: Effect of vitamin D supplementation on testosterone levels in men
This study was conducted to understand whether vitamin D supplementation affects testosterone levels in men. The study included 54 non-diabetic men undergoing weight reduction programme. 31 participants were given 83 μg or 3332 IU’s Vitamin D daily for a year, and 23 participants were given a placebo.
- Males who supplemented with Vitamin D had 25.2 percent higher testosterone levels compared to the placebo group.
- There was an increase in free testosterone, bioactive testosterone and total testosterone levels in the Vitamin D supplementation group.
Study: Additive benefit of higher testosterone levels and vitamin D plus calcium supplementation regarding fall risk reduction among older men and women
The study included 199 men and 246 women ages 65+. Their baseline sex hormone levels were assessed and tracked for three years. The analysis was controlled for various factors such as 25-hydroxyvitamin D, vitamin D plus calcium treatment and sex hormone binding globulin.
Older men who take Vitamin D were less likely to have low testosterone levels compared to men who did not. Adequate levels also translated to a 60 percent lower chances of falling
Study: Vitamin D levels are associated with reproductive health parameters
Authors took up this exploratory survey to find the relationship between the vitamin D levels in the body and reproductive parameters like sperm motility and hormone levels. 170 healthy men with an average age of 29 years were taken in the study and blood samples were collected to quantify the levels of various hormones and vitamin D.
Result: Very high and very low levels of vitamin D showed poor levels of reproductive hormones and sperm motility. Optimal levels of vitamin D have been established as 30ng/ml in serum.
Conclusion: Optimal levels of vitamin D in blood help maintain biologically essential levels of reproductive hormones like testosterone, FSH, LH and good progressive motility of sperm.
Study: Very high levels of vitamin D spoil the semen parameters
Authors took up serum vitamin D and reproductive hormone quantification along with semen analysis in 307 men.
Result: High Vitamin D levels were consistently linked with compromised reproductive hormones and semen parameters like sperm morphology and motility. Very few men were deficient in vitamin D in the study sample and authors could not conclude on correlation of low vitamin levels and reproductive hormones.
Conclusion: High Vitamin D levels lead to lower levels of reproductive hormones and semen parameters.
Study: Vitamin D is essential for reproductive development in mice
In this study mice that are genetically devoid of vitamin D receptors were evaluated for the development of male and female gonads. The study hypothesized that without the specific receptors cells, mice cannot take up vitamin D and perform biochemical processes such as the synthesis of reproductive hormones and calcium absorption. Any impairment of reproductive systems indicates low testosterone levels and reduced calcium uptake leads to weak bones.
Result: Mice with no vitamin D receptors show uterine abnormality in female and testicular malformations in male mice. These malformations ultimately lead to reduced or no reproductive hormones like testosterone.
Conclusion: Vitamin D is essential for the development of reproductive organs and the biosynthesis of hormones in both male and female mice.
Study: Vitamin D deficiency in the brain leads to low testosterone levels in male rats
Sonnenberg and coworkers induced vitamin D depletion in rats and measured various enzymes that are responsible for neuroendocrine (brain regulated hormonal secretions) functions. This investigation was taken up to study the effects of vitamin D on brain function.
Result: The levels of key enzymes like choline acetyltransferase were reduced in vitamin D depletion. The testosterone levels were recorded as significantly low in parts of the brain which have a neuroendocrine role (hypothalamus).
Conclusion: Vitamin D levels are directly proportional to the testosterone levels in rats.
So Does Vitamin D Increase Testosterone?
The animal studies, human clinical trials and surveys strongly indicate the important role of Vitamin D in regulating testosterone levels. Vitamin D that has been implicated in the classical role of bone health has an important additional role in the reproductive and immune systems, and in preventing certain cancers.
Testosterone, an important reproductive hormone, is positively regulated by vitamin D and enhanced vitamin D levels have been shown to improve testosterone levels in humans and mice. However, vitamin D in high levels causes the reverse effect on testosterone levels and other semen parameters including a deleterious effect on the liver, suggesting that excessive intake of Vitamin D is not desirable. Vitamin D supplements should be taken only after consultation with a physician and a test on the blood/serum vitamin D levels.
Best Way to Get Vitamin D
The best way to get this Vitamin is from direct skin exposure to sunlight. When ultraviolet B rays hit the skin, it is absorbed by 7-dehydrocholesterol, a type of cholesterol naturally found in the skin. It gets converted into cholecalciferol, which is the pre-vitamin form of D3. It is then transported to the liver where it is converted into hydroxyvitamin D or 25(OH) D, and finally, it is converted into 25(OH) 2D in the kidneys. This is the form of Vitamin D that can be used by the body.
To get adequate Vitamin D, different people require different amounts of sun exposure. Generally speaking, if you expose your skin long enough to the sun so that it turns pink, your body can produce up to 25,000 IU of Vitamin D3. However, you need to expose a large part of your body to the sun, and the best time to do is between 10 AM and 3 PM. This should ideally be done at least 2-3 times a week.
You can also get Vitamin D from dietary sources such as fortified drinks, salmon, herring, mushrooms, eggs and fortified cereals. However, it is not possible to get all the Vitamin D you need from food. If you do not get adequate sun exposure or you don’t eat enough Vitamin D containing foods, you can consider taking supplements.
The optimal amount of vitamin D for testosterone levels in the blood is around 50-70 ng/dl. The safe upper limit for adults is 4,000-5,000 IU of vitamin D daily.
We have sufficient scientific evidence to prove that Vitamin D does affect testosterone levels. If you have low Vitamin D levels, you are much more likely to have low testosterone levels. Vitamin supplementation can help increase testosterone levels in the bloodstream. However, if you already have adequate Vitamin D levels, supplementation may not cause an increase in testosterone levels.