Effect of vitamin D on testosterone levels

The effect was about null.

Thanks for that input Firegoat,

I get enough sun to maintain a light suntan year round, so the supplementation will help to smooth out those cloudy times for me, I was already taking 1000iu daily for this reason so it is easy to just take a couple more. Next time I get my blood done I’ll check the level and compare it to the baseline.

Hi Marinera,

Thanks for joining in, I always look for your input and appreciate it in threads.

Compared to baseline values, a significant increase in total testosterone levels (from 10.7 ± 3.9 nmol/l to 13.4 ± 4.7 nmol/l; p < 0.001), bioactive testosterone (from 5.21 ± 1.87 nmol/l to 6.25 ± 2.01 nmol/l; p = 0.001), and free testosterone levels (from 0.222 ± 0.080 nmol/l to 0.267 ± 0.087 nmol/l; p = 0.001) were observed in the vitamin D supplemented group. By contrast, there was no significant change in any testosterone measure in the placebo group. Our results suggest that vitamin D supplementation might increase testosterone levels.

It may not seem like much to you but to me any increase that the body will produce itself is significant.
Also that the study was on “healthy overweight men” undergoing a weight reduction program. it’s well known that overweight men produce less testosterone than fit men

From the second study
Indeed, plasma vitamin D levels were associated inversely with body mass index (BMI) and fat levels and positively with HDL cholesterol [75]. Furthermore, visceral adipose tissue was higher in vitamin D deficient subjects. Sequestration of vitamin D in body fat stores and its consequent reduced bioavailability offer a plausible explanation for this association

Finally, vitamin D enhances the effect of anti-estrogen-like substances. In addition to these general/indirect effects, it has been shown that vitamin D increases T levels. This is primarily due to vitamin D being able to decrease the enzyme aromatase, which converts T into E2.
In fact, vitamin D reduces the production of E2 itself and blocks the production of the alpha-E2 receptor [81]. Thus, vitamin D increases T levels, as further confirmed by a study in which men with sufficient 25(OH)D levels had significantly higher levels of T and significantly lower levels of SHBG than 25(OH)D-insufficient men [82]. Moreover, Pilz and colleagues reported that vitamin D supplementation increases T levels

This leads me to wonder how much better the effect would be on healthy lean men who regularly weight train. It may not be the be all and end all but it may help.

I welcome more input from you as I genuinely respect your very inquisitive mind, you often point out things that I miss

WOW! Looks like tanning beds might not be so bad afterall ay

Well sun exposure close to midday seems to be considered best practice for raising Vitamin D, but Firegoat has a good case with the battery scenario, which seems about right from my delving.

So I guess tanning beds would help, at the moment I am in the sunshine state and basking in it, plus upping my Vitamin D supplements, I like the shotgun approach, “hit it with both barrels at once for maximum effect”, no use pontificating which will work better. :)

Half way through a 5000iu supplement month then I’ll tone it back to 3000iu whacked in the full spectrum Vitamin E too just to be on the right track, I must say I am feeling very good now days and very strong too :)

An interesting article

“D” is for Doping

"D" is for Doping
by Chris Shugart

"D" is for Domination
In 1927 a controversy arose in the athletic world.
The German Swimmers’ Association had decided to use a sunlamp on their athletes to boost performance. Some felt this ultraviolet irradiation constituted "athletic unfairness."
In other words, doping.
How could sitting under a sunlamp be construed as doping? Because, according to Dr. Tim Ziegenfuss, this artificial sunlight penetrates the skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes 1,25 dihydroxy vitamin D in the kidneys.
That in itself might not constitute athletic unfairness, but if you’re deficient in Vitamin D (which is pretty damn common), then modern studies have shown that it can indeed be a performance enhancing substance.
The irradiation of athletes has continued since.
Fast forward to May 2009, a headline in the Post Chronicle:
"Vitamin D May Allow American Olympians To Dominate In 2012"
This headline was a reaction to a new paper published by The American College of Sports Medicine on the positive effect of adequate Vitamin D on athletic performance.
Now, although some scientists, including Dr. Tim Ziegenfuss, would not classify Vitamin D as a hormone, its metabolic product (calcitriol) is a secosteroid hormone (a molecule that’s very similar to a steroid). In fact, many come right out and classify Vitamin D as a steroid hormone.
But is this really doping?
Most experts agree that it’s not.
The majority of athletes — like the majority of people in the general population — are deficient in Vitamin D. Treating this deficiency can help athletes prevent stress fractures as well as maintain a healthy vitality. If this also happens to improve the athlete’s reaction time, muscle strength, speed, and endurance, well… that’s just a very nice side effect of getting adequate Vitamin D.
So Vitamin D has been making waves in the athletic community since at least 1927, but it’s also becoming a hot topic in another field: life extension. Add to this some evidence that it could help with fat loss and strength gains, and you just might have…

The Next Big Vitamin
Dr. Jonny Bowden calls Vitamin D the most underrated "vitamin" on the planet. (Quotation marks because it isn’t technically a vitamin at all.)
Dr. Ziegenfuss, a researcher and sports nutritionist to elite athletes, tests himself often to make sure he’s getting enough. He even tests his kids for it and supplements them as needed.
Coach Eric Cressey says Vitamin D might just be the next fish oil. He makes sure the athletes under his care get plenty of it. Charles Poliquin does the same.
And finally, medicinal chemist Bill Roberts says that you should "absolutely" be taking Vitamin D.
What about the stuffy and often behind-the-times nutritional organizations and agencies? Well, the FDA has stated that they’re likely going to up their Vitamin D recommendations the next time they release new standards.
In October of 2008, the American Academy of Pediatrics doubled the amount of D they recommend for kids (from 200 IU per day to 400 IU per day). And the Department of Family and Consumer Sciences at the University of Wyoming has recommended that sports nutritionists assess levels of Vitamin D in their athletes. If they’re getting too little, they contend it will compromise the athlete’s ability to train.
From government agencies to in-the-trenches trainers, the trend is clear: Vitamin D is important. And if you think you’re getting enough of it from natural foods, fortified foods, and sunlight, then think again, Sunshine.

Vitamin D: Why Should You Care?
Three reasons: Longevity, performance, and lookin’ good naked.
Let’s break those down:
1) Longevity
You know what really gets in the way of building muscle, losing fat, and benching a ton?
Death.
The New England Journal of Medicine recently warned that the number of diseases associated with vitamin D deficiency is growing. And who’s deficient? Most people, the studies seem to be saying, including otherwise nutrition-conscious athletes and gym rats.
In one mind-blowing study (Melamed, et al.) using population data, researchers found that total mortality was 26% higher in those with the lowest 25(OH)D levels compared with the highest. And a meta-analysis of 18 randomized controlled trials found that supplemental vitamin D significantly reduced total mortality. That means quite simply this: vitamin D supplementation prolongs life.
Here’s just a handful of examples:
• According to the Vitamin D Council, current research has implicated vitamin D deficiency as a major factor in the pathology of at least 17 varieties of cancer.
• Vitamin D may protect against both Type I and Type II diabetes.
• Low D may contribute to chronic fatigue, depression, and Seasonal Affective Disorder.
• Parkinson’s and Alzheimer’s sufferers have been found to have lower levels of D.
• Low levels of vitamin D may contribute to "Syndrome X" with associated hypertension, obesity, diabetes, and heart disease.
• Administration of dietary vitamin D has been shown to lower blood pressure and restore insulin sensitivity.
This section could go on endlessly, so let’s just say this: If you care about living a good long life, then Vitamin D looks like it could certainly help with that goal.
2) Performance
Studies on Vitamin D, sunlight, and performance go back for decades. Russian studies in the 1930’s showed that 100M dash times improved in irradiated athletes vs. non-irradiated athletes undergoing the same training (7.4% improvement vs. 1.4%).
German studies in the 1940’s showed that irradiation lead to a 13% improvement in performance on the bike ergometer vs. no improvement in the control group.
In the 1950’s researchers saw a "convincing effect" on athletic performance after treating athletes at the Sports College of Cologne. Findings were so convincing that they notified the Olympic Committee.
At one point, even school children were irradiated and given large doses of Vitamin D in 1952 Germany. Treated children showed dramatic increases in overall fitness and cardiovascular performance. UV radiation was also shown to improve reaction times by 17% in a 1956 study.
In the 1960s, a group of American college women were treated with a single dose of ultraviolet irradiation. The results: improvements in strength, speed, and endurance.
Other studies showed "distinct seasonal variation" in the trainability of musculature. Basically, athletes performed better and got stronger in the late summer due to their greater exposure to the sun and subsequent Vitamin D production.
Vitamin D has also been shown to act directly on muscle to increase protein synthesis. Deficient subjects administered Vitamin D showed improvement in muscle protein anabolism and an increase in muscle mass.
Improvements in neuromuscular functioning have also been seen. People with higher levels of Vitamin D generally have better reaction time and balance.
3) Looking Good Naked
If Vitamin D does indeed improve the effects of training and helps to stave off various illnesses, then it’s easy to see how this can translate into an improved aesthetic: you’re healthier, you feel better, you get more out of your training, and you end up looking better when you make sexy-time. But there could be a more direct effect as well.
Dr. Shalamar Sibley’s new research shows that adding Vitamin D to a reduced-calorie diet may lead to better, faster weight loss. Not only did she find that excess body fat came off faster when plenty of D3 was present, but it also came off the abdominal area.
The icing on the cake? The same D-supplemented subjects retained muscle mass while losing the fat.
In other studies, subjects receiving Vitamin D therapy lost weight, lost their sugar cravings, and saw a normalization in blood sugar levels.

The Quick and Dirty of D
Before we get to the T NATION recommendations, let’s review some Vitamin D basics and some little known facts:
• There is no RDA for Vitamin D due to "insufficient evidence." But there is an AI or Adequate Intake recommendation:
Ages 19-50: 200 IU
Ages 51-70: 400 IU
Over age 70: 600 IU
That means this is the amount assumed to ensure nutritional adequacy: sufficient to maintain bone health and normal calcium metabolism in healthy people. Suffice it to say, these are bare minimums that new evidence suggests are way too conservative.
• There aren’t that many foods in nature containing Vitamin D. The best source is halibut liver oil, followed by cod liver oil, salmon, tuna, and mackerel.
And by the way, farm-raised salmon has been shown to have 25% less Vitamin D than wild salmon. And cod liver oil? Good source of D but also high in Vitamin A, which can be toxic if over-consumed. Do NOT use cod liver oil alone to boost your Vitamin D intake!
Beef liver, cheese, and egg yolks contain a smidge. Foods like milk do contain Vitamin D but only because manufacturers add it in, i.e. fortified milk, fortified cereal etc. Milk was fortified back in the 1930’s to combat rickets, and it worked.
Despite all of this, those who wish to maximize the benefits of a higher Vitamin D intake wouldn’t be able to get enough through food sources alone. And of course a lot of that "fortified" food is still make-you-fat food, probably avoided by most physique athletes.
• Most people get their D through sunlight. The basic intake guidelines are: 5-30 minutes of sun exposure between 10 AM and 3 PM at least twice a week without sunscreen. But much depends on where you live, the pollution levels, cloud cover, age, the season of the year, your natural cutaneous melanin content, etc.
Another factoid: While it’s technically possible to get too much Vitamin D, you can’t get too much from the sun, only from over-supplementing.
• What about tanning beds? The "moderate use" of commercial tanning beds that emit 2-6% UVB radiation can help, but of course there’s that whole skin cancer thing to consider.
• Sunlight that comes through glass doesn’t count. Most UVB radiation doesn’t penetrate glass, corner-office boy.
• If using the sun to get your D, remember that cholesterol-containing body oils are critical to the absorption process. Some experts say that because the body needs 30 to 60 minutes to absorb these vitamin-D-containing oils, it’s best to delay showering for about an hour after sun exposure. And don’t jump right into the pool either as these natural oils can be stripped by chlorine.

How Much Vitamin D?
In researching this article, I looked to find a consensus among the experts. Here’s what I’ve found:
• As a general rule, Dr. Clay Hyght recommends 1,000 IU per day. This represented the low end amongst our experts, but note that it’s still way over current government guidelines.
• Canadian researcher and one of the world’s foremost experts on Vitamin D, Dr. Reinhold Vieth, says levels should be in the range of 4,000 IU from all sources.
• Dr. Bowden recommended 2,000 IUs per day.
• Dr. Ziegenfuss personally keeps his levels of 25-hydroxy D at 50 to 100 ng/mL. That means he uses around 4000 IU per day. (He lives in Ohio, by the way.) He notes that when he took 1000 to 2000 IU per day his levels rarely hit 40.
• Bill Roberts has noted that 4,000 IU a day can be a substantial help to fat loss.
• The Vitamin D Council says that those who rarely get sunlight need to supplement with 5,000 IU per day. Note that this would take 50 glasses of fortified milk a day or 10-12 standard multivitamins, hence the need for targeted supplementation.
• Dr. Robert P. Heaney of Nebraska’s Creighton University estimates that 3,000 IU per day is required to assure that 97% of Americans obtain levels greater than 35 ng/mL.
So the government says 200 to 400 IU for most of us, but even they admit that’s low. Those more in-the-know suggest anywhere from 1000 to even 5000 IU per day.
But this may depend on how much sunlight you get and your ethnicity. Some estimate that dark-skinned individuals, brown and black guys if you will, may need double the amount of D that a pasty white guy needs.
T NATION will leave your personal dosage choice up to you and maybe your physician (if he knows a damn). If you really want to dial this in, we suggest getting tested. (See section below.)

General Recommendations
1) When looking for a Vitamin D supplement, choose the D3 form. Gelcaps are probably best. Liquids are favored by some. Since D is fat soluble, take with foods containing a little fat to optimize absorption. Polyunsaturated and monounsaturated fatty acids are best.
2) Get some sun when you can, but don’t burn. The occasional use of tanning beds is also fine, particularly in the winter.
3) If in doubt, test. The test you want to ask for is 25 (hydroxy) D. That’s 25-hydroxyvitamin D, not 1,25-dihydroxyvitamin D.
The Vitamin D Council says you should shoot for blood levels between 50—80 ng/mL. The average American in late winter averages about 15 to 18 ng/ml, which would be considered a serious deficiency. Your doctor can give you this test and some home testing kits are available (around $65 each), although we cannot endorse one at this time.
4) It’s wise to ensure adequate calcium intake when increasing your intake of Vitamin D.

Can You OD on D?
Yes. But it’s unlikely.
Dr. Vieth suggests that critical toxicity may occur at doses of 20,000 IU daily (for many months), and that the Upper Limit (UL) of safety be set at 10,000 IU, rather than the current 2,000 IU.
So while toxicity issues exist, you probably won’t have to worry about it when staying at 5000 IU per day or less according to most forward-thinking researchers and nutrition experts.

Good Dope
As we "go to press" I just received another study about Vitamin D from the Public
Health Agency of Canada (PHAC). It seems that Vitamin D may offer protection against Swine Flu, the H1N1 virus.
In short, if you get plenty of Vitamin D and catch the flu, it’s a mild illness. If you’re lacking — and most people are, especially in the winter — then you’re more likely to develop full-blown symptoms.
The message is loud and clear: It’s time to start "doping" with Vitamin D.

References and Further Reading
Melamed ML, Michos ED, Post W, Astor B. 25-Hydroxyvitamin D levels and the risk of mortality in the general population. Arch Intern Med. 2008;168(15):1629—37
Autier P, Gandini S. Vitamin D supplementation and total mortality: a meta-analysis of randomized controlled trials. Arch Intern Med. 2007;167(16):1730—7.
Vitamin A Saga - The Weston A. Price Foundation
Vitamin D - Health Professional Fact Sheet
Athletic Performance and Vitamin D , JOHN J. CANNELL, BRUCE W. HOLLIS, MARC B. SORENSON, TIMOTHY N. TAFT, and JOHN J. B. ANDERSON
http://www.vitamindcouncil.org

Now this is very interesting, albeit long and complex

1,25(OH)2Vitamin D3 Stimulates Myogenic Differentiation by Inhibiting Cell Proliferation and Modulating the Expression of Promyogenic Growth Factors and Myostatin in C2C12 Skeletal Muscle Cells

http://www.ncbi .nlm.nih.gov/pm … les/PMC3138228/

Just the link though because it’s long and complex (but well worth the read).

And a nice summary from

Vitamin D – A potential myostatin inhibitor
by theathleterx
11 Mar

Vitamin D has been the darling of the supplement world for the last 5 years. You literally can’t go a week without reading a new study extolling its benefits. Everyone from nutritionists to pain specialists to personal trainers are recommending it to their patients. And with the amount of research supporting it, they should be.
A surprising and little known benefit of vitamin D, especially for athlete’s is its ability to inhibit myostatin and increase follistatin. Although the research is still limited, it’s worth seriously considering adding vitamin D to an athlete’s supplement arsenal.

Myostatin, Muscle, and the Athlete
Supplement companies and researchers in the fields of oncology, AIDS, and muscular dystrophy have been salivating over it. And in all honesty, they should be.

Myostatin is a key, if not THE key, regulator to muscle growth. Even though we don’t full understand the complex pathways it uses to regulate muscle growth, there’s no question it’s a major player. If you think of testosterone as the gas pedal for muscle growth, then myostatin is the brake. By inhibiting it, the potential for big, strong muscles is almost unlimited.

The really interesting thing about myostatin is: 1.) It appears as though myostatin can be found almost exclusively in skeletal muscles. Thus, myostatin inhibitors should have minimal side effects and not alter the hypothalmic-pituitary-gonadal axis. 2.) Myostatin inhibition appears to not only increase protein synthesis within existing muscle fibers, but also activates satellite cells. So in conditions like end stage muscular dystrophy and age-related sarcopenia where the pool of available satellite cells are almost depleted, it can still help.

Follistatin: Better than deleting the myostatin gene?
And here’s where it may or may not get even better…

The Good

As the researchers continued to study the pathway, they realized myostatin had an arch nemesis, follistatin (Yes, an inhibitor for an inhibitor). And follistatin wasn’t just an inhibitor to myostatin, but also activin, which was another inhibitor of muscle growth. Thus, follistatin actually showed greater muscular growth than just inhibiting the myostatin gene.

The Bad

Don’t get too excited though. Unlike myostatin, follistatin appears to affect more than muscular growth. We know that it can impair FSH release (possibly leading to infertility) . We also know it’s distributed throughout the body. Plus we don’t really quite understand all of its roles just yet. Thus, the potential for side effects are increased compared to inhibiting myostatin. Even if we find out it’s only downside is impairing FSH release, will it be worth it?
There is an isoform of follistatin that researchers suggest affects primarily muscular growth. However, until further research is done and we begin to understand the entire follistatin picture, I’d still be hesitant to choose follistatin over a pure myostatin inhibitor.

Myostatin and Muscular Injuries

There’s one more interesting aspect of the myostatin pathway, especially for athletes. It appears as though inhibiting myostatin also reduces muscle fibrosis. For athletes recovering from an injury, a myostatin inhibitor offers a double whammy: 1) increased protein synthesis in existing muscle fibers and activation of satellite cells thereby increasing muscle mass and strength. 2) reduction of fibrosis thereby reducing residual damage from the injury.

Vitamin D’s Role in the Myostatin Pathway

1,25(OH)2Vitamin D3 Stimulates Myogenic Differentiation by Inhibiting Cell Proliferation and Modulating the Expression of Promyogenic Growth Factors and Myostatin in C2C12 Skeletal Muscle Cells

The study was relatively simple. The researchers split mouse C2C12 skeletal muscle cells into two groups: 1) a treated group (soaked in 100nM of vitamin D 2) an untreated group. Then over a 10 day period, the researchers used a handful of complex tests (immunefluorescence, PCR, Western blottings, ICC, etc) to answer two very important questions:
1. Does vitamin D autoregulate its own receptor?
2. Does vitamin D influence myogenesis?
The Vitamin D Receptor
Vitamin D does appear to autoregulate its owns receptor, which wasn’t that surprising. What was surprising was that it appeared to downregulate its receptor after several days of treatment, much like other hormones do.
Vitamin D and Muscle Growth

The results:
• Up to an 85% reduction in PCNA expression (cell proliferation), P<0.0001
• A 4-fold increase in MyoD expression, P<0.001
• A 6-fold increase in desmin, P<0.001
• A 2-fold increase in mean diameter of fibers, P<0.001
• A 2.5-fold increase in size (width), P<0.001
• A 3-fold decrease in IGF-1 expression, P<0.01
• A A 2.5-fold increase in IGF-2 expression, P<0.01
• Up to a 10-fold decrease in the expression of Myostatin, P<0.001
• A 2.5-fold increase in Follistatin expression, P<0.01

Impressive, isn’t it? Not only did they have specific myogenic markers and transcription factors that suggest vitamin D’s role in muscular development, but they also had visible differences in fiber diameter and width.

One statistic was particularly interesting to me, and in my opinion, might be the most interesting finding in the study. Vitamin D appears to not only increase follistatin expression (which will bind any available myostatin and make it useless), but also appears to decrease myostatin production at the mRNA and protein level. So it can possibly reduce myostatin activity AND expression.

I’m feeling pretty good on the 5000iu a day of vitamin D so I’m going to stay at that level, the added broad spectrum Vitamin E is also feeling pretty good, and I’ll soon be on a high dose of K2 MK-4 to compliment the deal plus I have upped my Magnesium as well.

I’m feeling stronger for it and having to restrict my lifting to allow tendons to keep pace, the muscle seems to be packing on pretty fast now but I have to be careful about the connections. I must say though a badly strained forearm tendon healed in three weeks which is just insane and a triceps attachment that went very bad took two weeks to come good, mind you there are other supplements at work as well

All in all I love the Vitamin D, next blood test I get I will have it checked and possibly up it further.

This would explain why in mid summer every year I get so freakn horny …

I have mentioned in another thread that the D3 I am taking, makes me horny for sure, but has the side-effect of making me feel like I am coming down with a cold. Does anyone else have this experience. Did you try switching brands?

I’ve been taking Nature’s Best D3 1000iu - supposed to be 1 a day, but I take 2 because my D3 levels tested as ‘almost a vampire’. I feel much better on them; no negative reactions at all. I like Nature’s Best supplements if I’m not forking out for Solgar.

Want Vitamin D? Just get out in the sunshine folks.

I honestly don’t believe we were meant to live in the cold or indoors. Maybe that’s why man began in Africa?

:)

Ain’t much sunshine around here. Can’t do my job outside. And I don’t own a rag-top car. I don’t live in an ideal world, so I have to make do.

When do you take your Vitamin D, what do you take it with, have you had blood tests done at all recently, how’s your thyroid in those tests?

It might be worth checking with your GP what is going on, generally if Vitamin D makes someone feel unwell then something else is out of whack or causing it.