Vitamin D and Low Testosterone: Does Research Support a Connection?
Vitamin D, often referred to as the sunshine vitamin, is produced by the body when the skin is directly exposed to the sun. Lower-than-normal vitamin D levels could result from a lack of outdoor activity, and it has been hypothesized and publicized that vitamin D is associated with testosterone production in men.
Men are asking:
- Is there a scientifically substantiated connection between vitamin D and low testosterone?
- Is it possible that more Vitamin D would cure my low testosterone?
The Role of Vitamin D
According to the Center for Disease Control (CDC), research shows that somewhere between 10% and 30% of Americans are historically at risk for vitamin D deficiency.
Vitamin D is an important fat-soluble nutrient important for maintaining bone health and facilitating the absorption of minerals such as calcium and magnesium. It’s found naturally in only a few foods, but it can be found in some mushrooms and fatty fish, such as sardines, mackerel, and salmon. Milk is often fortified with vitamin D.
Vitamin D may play a role in other areas of your health, such as:
- Regulating cell growth
- Immune system support
- Maintaining neuromuscular and cardiovascular health
- Stimulating muscle growth
- Reducing unnecessary body fat
Dietitians and doctors often recommend vitamin D supplements due to the high rates of deficiency they find among their patients.
Vitamin D and Testosterone: What Does the Research Show?
Some research supports a significant relationship between adequate levels of vitamin D in the body and total testosterone levels.
For example, a 2012 study published in Clinical Endocrinology showed that certain concentrations of vitamin D in the blood stream could be associated with reduced risks of hypogonadism (the medical term for Low T). However, increases in total testosterone and free testosterone plateaued once vitamin D levels optimized.
This would indicate that you won’t significantly increase your testosterone production beyond a “normal” level by taking large doses of vitamin D, but you can improve your overall health if you’re vitamin D deficient.
In a 2011 randomized controlled study, researchers found men who were given a daily high-dose vitamin D supplement significantly increased their total testosterone from 10.7 nmol/L to 13.4 nmol/L. In contrast, the group given a placebo saw little to no improvements in testosterone production.
These findings suggest that men deficient in vitamin D who take a proper vitamin D supplement may bring low testosterone levels closer to normal.
However, this study took its subjects from a weight loss program, where “healthy” overweight men undergoing a weight reduction program were analyzed for testosterone levels. It would be difficult to say that the improved testosterone levels were exclusively due to increased vitamin D supplementation, and not (at least partially) due to the overall improvement in the subjects’ health resulting from weight loss.
Testosterone and Vitamin D Supplements: Not All Research Is Favorable
Other studies show that vitamin D supplementation has no direct impact whatsoever on testosterone levels.
A 2019 study published in the European Journal of Nutrition evaluated whether vitamin D supplementation increases serum total testosterone levels in 100 men with low baseline total testosterone levels (defined as serum TT levels < 10.4 nmol/l). The subjects were randomized to receive 20,000 IU of vitamin D3/week or a placebo for 12 weeks.
The researchers measured total testosterone using mass spectrometry, as well well as observing the following potential secondary outcomes:
- Free testosterone
- Sex hormone-binding globulin
- Free androgen index
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH)
- Metabolic characteristics
- Body composition
The authors of the study simply concluded:
“We found no significant treatment effect on serum TT (total testosterone) or on the remaining secondary outcome variables.”
Testosterone and Vitamin D: What Does It All Mean?
Research into vitamin D as a treatment for low testosterone is inconclusive, which really comes as no surprise.
No food or vitamin supplement, including vitamin D, acts as a silver bullet that will return clinically low testosterone levels to normal.
However, testosterone and your diet, which includes your vitamin D intake among many other factors, are connected. Your general nutrition and overall health are critical to a healthy hormone balance. Proper nutrients are necessary for your body to operate at a high level. It’s important to pay attention to the vitamins, minerals, and calories that you take in daily through your diet.
If your testosterone levels are simply on the low end of normal, changing your diet or increasing vitamin D may be what you need to get your levels a little higher and out of symptomatic territory.
On the other hand, if you suffer from clinically diagnosed low testosterone, better dietary choices or improved exercise routines are unlikely to restore your hormone levels to normal.
It is much more likely that you’re going to require Testosterone Replacement Therapy (TRT) to return your body to normal and maintain that healthy hormonal balance.