Update 4/9/23. I was giving a podcast interview recently and was asked a question I don't think I've ever heard before: do vitamin D supplements raise testosterone levels? I had to say, at the time, while I was skeptical, I was not 100% sure. Curious about this, I did make a note to myself to look into it afterward. Sure enough, after the interview was over, a quick online search revealed a lot of people asking that same question and many websites giving a resounding yes, that vitamin D did raise, in fact testosterone levels! With respect to those other websites, I preferred to do my own investigation on this issue. Fortunately, there are studies on this topic. Because vitamin D is so popular, I also want to answer other common questions too. Keep reading and let's see what I discovered. Also, read the Tribulus Terrestris review.
Who's Lacking Vitamin D?
Vitamin D (also called calciferol and cholecalciferol) is not in many foods, so getting enough may be more difficult than some think. As I see it, those who might be at the greatest risk include:
- Older adults and those in nursing homes.
- Overweight individuals.
- People who live in the north, where sunlight is scarce.
- Those who spend most of their time indoors.
- Those who regularly cover most of their body in clothing.
- People with dark skin.
Some medical conditions and medications can cause cholecalciferol deficiency.
Will The Real Vitamin D Stand Up?
Vitamin D supplements come in two forms:
- Vitamin D2 (ergocalciferol)
- Vitamin D3 (cholecalciferol)
Vitamin D3 is considered the most potent form because this is the same type as we make when we are exposed to ultraviolet B rays of sunlight. Before it can become active, vitamin D must undergo some processing. First the vitamin gets processed in the liver, where it is converted to 25-hydroxyvitamin D (25-OH-D), sometimes called calcidiol. That molecule in turn, gets converted in the kidneys to the active form called 1,25-dihydroxy vitamin D.
In order for vitamin D to work, it needs to connect to vitamin D receptors. Every cell in your body has receptors for vitamin D. This includes the testing and even sperm cells. This tell us that the vitamin likely has many diverse effects in the body. If you are scrutinizing for a vitamin D test, look for one that measures 25-OH-D. Measuring levels of 25-OH-D provides a good indication of what your levels of the active hormone are.
Vitamin D: Vitamin or Hormone?
Why might vitamin D be related to testosterone levels? Well, if calciferol were discovered today, it would probably not be called a vitamin. Instead, it would likely be called a hormone. Vitamin D looks more like a hormone than a vitamin. Their chemical structures are similar. And, like hormones, vitamin D appears to have a wide range of effects. While cholecalciferol is well known for its role in bone health, research suggests it may also take part in helping:
Playing a role in these diverse health conditions points to vitamin D as more of a hormone than a vitamin. Since hormones tend to look like each other and have different effects depending on the tissue we are talking about, it makes some sense how people might wonder if it could in some way be related to testosterone levels. Indeed, some studies point to an association between testosterone and vitamin D as well.
Association vs. Cause & Effect
As you read through the research section below, you will see the word “association” used a lot. An association or correlation does not necessarily mean two things are connected to each other. For example, many people go to work when the sun rises, but that does not mean the sun causes people to go to work. It just so happens that both often occur around the same time. The same might be true with testosterone and cholecalciferol too.Keep this in mind as you read the studies that show an association between vitamin D and testosterone levels. Instead, pay more attention to the studies where vitamin D supplements were given to people to see if they raised testosterone.
Does Vitamin D Raise Testosterone? The Proof
The best way to know for sure if vitamin D is related to testosterone levels is to test it. Here is a summary of the human research that's been conducted. This list involves only human research.
Vitamin D and Hypogonadism
Hypogonadism refers to a condition where the testes are not making enough sex hormones, like testosterone. It appears that vitamin D is needed for proper gonad functioning.
Researchers in China noted low vitamin D levels were associated with hypogonadism in 2845 middle-aged men. The average age of the men was 53 years.
Because low vitamin D and low testosterone can also be related to being overweight, the researchers speculated this may play a role in some of the cases they observed.
Ironically, these other researchers found just the opposite – that low D levels were not associated with hypogonadism or low testosterone in 225 middle-aged men. Oddly, this study also suggested that too high levels of D might actually increase hypogonadism risk.
Vitamin D and Testosterone Research
Researchers noted higher levels of testosterone were associated with higher D levels. This investigation involved 2299 men who had normal levels of the androgen. In addition, sex hormone binding globulin (SHBG) was higher as well.
Researchers in Malaysia likewise saw a significant association between testosterone and sex hormone binding globulin (SHBG) and vitamin D when they looked at 382 young men.
In another investigation involving over 400 men, those who had 25-OH vitamin D levels above 75 nmol/L had not only higher testosterone but also improved physical performance compared to those whose vitamin D levels were less than 75 nmol/L.
Researchers in Korea, looking at 652 middle-aged men, noted an association between calciferol and testosterone. The lower the D, the lower the testosterone; the higher the D levels, the higher the testosterone. This association varied by a change in seasons too. In other words, levels of both were higher during sunnier months than during winter months when there was less sunlight available.
In a study that involved 54 overweight men (who did not have diabetes), it was revealed that vitamin D supplements raised testosterone levels. The study lasted one year. The men were given either a placebo or 3,382 IU (84.5 mcg) of vitamin D daily. While encouraging, the men started the study with below-normal levels of both vitamin D and testosterone.
Keep in mind because because cholecalciferol might work in those who are deficient does not necessary indicate it works in people with normal testosterone levels.
In another investigation researchers looked at 1362 men and noticed that higher cholecalciferol levels were associated with higher testosterone levels. The connection, however, was not perfect because it seemed to vary according to where the men lived, being strongest for men who lived in the northeast and south but not elsewhere.
Other researchers saw no increase in testosterone levels when reviewing previous studies where high-dose vitamin D was given to men with low testosterone levels. The number of supplements used ranged from 500 mcg to 1000 mcg (20,000 IU – 40,000 IU) per week. Also interest was that giving men testosterone did not raise vitmain D levels.
In 2015 researchers analyzed cholecalciferol levels from 3 different investigations to see if they were related to testosterone levels. The people in these three studies included:
- Men with heart failure
- Nursing home patients
- Men from the Netherlands
The amount of vitamin D used in the studies ranged from 15 mcg to 50 mcg per day (600 IU per day to 2000 IU). Results revealed no testosterone benefits from D supplementation.
In this study, researchers looked at the effects of vitamin D in both healthy and non-healthy people going through dialysis. 103 of the people were healthy, and 33 individuals were receiving hemodialysis. The people were given either a placebo or 20 mcg (800 IU) of vitamin D for three months. The results revealed no significant changes by vitamin D on testosterone levels in either the healthy people or dialysis patients.
In another investigation, researchers followed 98 men with normal testosterone levels for three months. They compared the effects of 500 mcg of vitamin D vs. a placebo. They found that vitamin D did not raise total testosterone levels.
Vitamin D Testosterone and PCOS
Sometimes, too much testosterone can be a problem, such as seen in women with polycystic ovary syndrome (PCOS). One study, involving 12 overweight/vitamin D deficient women were reported to have reduced total testosterone levels and blood pressure. This investigation lasted three months. Women were given cholecalciferol supplements that ranged from 88 mcg to 213 mcg per day (3533 IU to 8533 IU).
Summary: Testosterone/ Vitamin D research
Reading the research can be confusing so here is a quick way to see all the research next to each other to help you make your own decision.
| Study Name | Study Details | Study Results |
|---|---|---|
| Effect of vitamin D supplementation on testosterone levels in men | 54 overweight men given 3,332 IU vit D for 1 year | Vitamin D raises testosterone |
| Supplementation with vitamin D does not increase serum testosterone levels in healthy males. | Vitamin D used ranged 20,000IU - 40,000 IU per week | Vitamin D does not raise testosterone levels |
| Vitamin D supplementation and testosterone concentrations in male human subjects. | results from 3 previous studies used. Vitamin D ranged from 600IU per day to 2000 IU per day. | Vitamin D does not raise testosterone levels |
| Association between plasma 25-OH vitamin D and testosterone levels in men | 1362 men | Vitamin D associated with higher testosterone |
| Vitamin D is significantly associated with total testosterone and sex hormone-binding globulin in Malaysian men | 382 men studied | Vitamin D associated with total testosterone and SHBG levels |
| Vitamin D is associated with testosterone and hypogonadism in Chinese men: Results from a cross-sectional SPECT-China study. | 2854 men | Low vitamin D associated with hypogonadism |
| Serum vitamin D levels and hypogonadism in men. | 225 middle aged men | Vitamin D not associated with hypogonadism or low testosterone |
| Therapeutic implications of vitamin D and calcium in overweight women with polycystic ovary syndrome | 12 overweight/vitamin D deficient women | Vitamin D lowers total testosterone and blood pressure in women |
| Serum 25-hydroxyvitamin D levels and testosterone deficiency in middle-aged Korean men: a cross-sectional study. | 652 men over 40 | Vitamin D associated with testosterone levels |
| Association of vitamin D status with serum androgen levels in men. | 2299 men | Vitamin D associated with testosterone levels |
| Associations of serum 25(OH)D levels with physical performance and anabolic hormones in young men | 412 men | Higher testosterone and physical performance in those whose vitamin D was greater than 75nmol/L |
| Vitamin D and Testosterone in Healthy Men: A randomized Controlled Trial | 98 healthy men in their 30s. | 500 mcg (20,000 IU) vs. Placebo for 3 months. No effect on T levels. |
| Serum Testosterone Levels Are Not Modified by Vitamin D Supplementation in Dialysis Patients and Healthy Subjects | 103 healthy and 33 dialysis patients | 20 mcg (800 IU) vitamin D vs placebo for 3 months. No changes in T levels in either group. |
Remember, “associated” does not necessarily mean D promotes higher testosterone levels. I recommend paying the most attention to the studies where D supplements were given to people.
How Is Vitamin D Measured?
The only way to know for sure if you are deficient or not is to get a blood test. Here, doctors will do what's often called a “25-hydroxy vitamin D test (also called 25-OH cholecalciferol ). The test is pretty inexpensive, costing about $50. Usually, people do not need to fast for this blood test.
At home vitamin D tests are also available.
What's a Normal Vitamin D Level?
What's normal for vitamin D is a bit controversial, depending on who you speak with. While a level of 30 ng/ml is often thought of as good, that amount only considers bone health. It does not take into consideration the other health benefits of vitamin D. Because of this, some set optimal ranges between 20 and 40 ng/ml while others advocate for between 30 and 50 ng/ml.
In my opinion, 20 ng/ml is not enough for most people reading these words.
The Endocrine Society lists 30 -100 ng/ml as sufficient but that is a very big range. In other words, should everybody be striving for is 100 ng/ml?
Currently, the non-profit Vitamin D Council recommends people aim for 50 ng/ml. To me, that sounds like a nice middle value for most. Here is a quick comparison between the Endocrine Society and Vitamin D Council recommendations.
| Endocrine Society | Vitamin D Counsel | |
|---|---|---|
| Vitamin D Deficiency | 0-20 ng/ml | 0-30 ng/ml |
| Insufficient in Vitamin D | 21-29 ng/ml | 31-39 ng/ml |
| Sufficient Vitamin D | 30-100 ng/ml | 40-80 ng/ml |
| Too Much/ Toxic Vitamin D | >150 ng/ml |
The Vitamin D Solution by Dr. Michael Holick is a great book to learn more about this nutrient.
Vitamin D Supplements: How Much Works?
The recommended dietary allowance is 15 mcg (600 IU) for those up to the age of 70. Beyond 70 years of age, the RDA is increased to 20 mcg (800 IU). On a blood test, 30 ng/ml is usually considered normal. Less than 20 ng/ml is considered vitamin D deficient. The Endocrine Society guidelines call for adults to range between 40 ng/ml and 60 ng/ml. To achieve this amount, they recommended supplements containing 37.5 mcg (400 IU) to 50 mcg (1000 IU).
Natural Ways To Boost Vitamin D Levels
If a blood test indicates you are low in cholecalciferol, how do you raise it? Well, some would say that the easiest way is to go outside for a few minutes when the sun is at its highest point in the sky (10 AM-2 PM). But that might not work for everybody such as older adults and those who live in more northern regions of the world. Older adults might also have fewer vitamin D receptors. This means they might not be able to manufacture vitmain D as well as younger people. Also our dermatologist friends will also rightly point out that too much sun can cause wrinkles as well as skin cancer.
Tanning beds probably won't help because most tanning beds only provide ultraviolet A rays (UVA rays). While UVA rays can cause skin cancer, they don't help the body make vitamin D. It's only UVB rays that make vitamin D.
Because vitamin D is a fat-soluble vitamin, it is stored in our fat cells. When we lose weight, those fat cells release the vitamin, improving blood levels.
Foods /products that contain cholecalciferol include:
- Salmon
- Tuna
- Milk/almond milk
- Yogurt
- Egg yokes
- Most protein powders
- Shiitake mushrooms
All that said, I think the most efficient way to raise vitamin D would be through supplementation.
When using over-the-counter calciferol supplements, a good rule of thumb to remember is that:
- 1,000 IU will raise blood vitamin D levels by about 10 ng/ml
- 2,000 IU will raise blood vitamin levels by about 20 ng/ml
Once you know your test results, you can pick a supplement that's right for you.
D3 vs D2? What's Better?
There are two types of nutrients found in supplements:
-
- Vitamin D3 – also called cholecalciferol (comes from the sun)
- Vitamin D2 – also called ergocalciferol (comes from yeast)
It's often said that D3 is better than D2 because vitamin D3 is the form we make from sunlight. Studies do seem to show D3 as better than D2 at raising blood levels but I don't believe that means D2 is useless. I say this because several studies have shown that vitamin D2 can reduce falls in older adults
If D2 was less potent than D3, why has it shown benefits?
While we might absorb D3 better, for the most part, I believe D2 and D3 are probably equally potent in many health benefits. This is good news for vegans who may prefer ergocalciferol.
Do You Need A Vitamin D Test?
When I give seminars, I often ask what supplements people take. For most, vitamin D is on the list. Many admit to taking the vitamin for many reasons. But, when I ask the follow-up question, “Have you had a vitamin D test?” Most say no.
When cholecalciferol started to become sexy, many people started getting tested to see if they were lacking or not. Since then, there has been a backlash where some are saying testing are not necessary. I'm not sure if I agree with that. Remember, cholecalciferol is a hormone-like compound. I'm usually not a fan of do-it-yourself hormone therapy because I don't know what that will do.
I also can't tell by looking at someone who is deficient. Even the people you'd think were fine might not be. As proof of this, I remember attending a conference once where the speaker – who was training for a triathlon – admitted to being deficient in vitamin D. This person was a young white guy who was spending much of his time outside swimming, running and biking – and yet he was still low!
Because of this, I recommend getting tested. This is especially true for those groups I highlighted at the beginning of this review.
So Does Vitamin D Raise Testosterone?
Over the years, I've met several seemingly healthy people who turned out to be low in vitamin D. While the research is intriguing, I'd still like to see a few better studies on the rising testosterone issue. For now, if I were asked the “does vitamin D raise testosterone” question again, I'd reply that if it really worked, it might be most likely to raise the hormone in those who were already low in vitamin D and testosterone, to begin with. How likely it might work I could not say because the research is not as complete as I'd like. For now, I do not feel vitamin D supplements raise testosterone in those who already have enough of these compounds.