Vitamin D Gets an A+ for Performance

Written by Heather

February 1st, 2010

By Heather Morgan

Most of you fit-o-holics are up on vitamin D and have even jumped on the bandwagon. If nothing else, you’re aware of the bone-building bennies. But it turns out the level of service provided to us by vitamin D is manifold. And we’re still just at the tip of the iceberg in our knowledge of it! So let’s take a look and see what it can do for your performance now and long into future.

According to Robert Heany, MD, about 99% of what we know about vitamin D has been revealed in the century we are in now. Some of that is because we can more easily measure it, which I’ll get to at the end. One thing we do know is that vitamin D is, in fact, not just a “vitamin”, per se. Vitamins are nutrients that must be brought into the body via the ingestion of food. It is common knowledge, however, that vitamin D can also be synthesized by the body when it is exposed to adequate sunlight with the proper amount of stimulating UV rays, in particular UVB. But really, vitamin D is defined as a “pluripotent pleiotropic secosteroid hormone”. (Thanks for clearing that up, right?) Translation: It’s a prehormone that is able to have many effects on various cell types and body systems. When produced in your skin or ingested, precholesterol (present in your tissues) is turned into cholecalciferol (aka. vitamin D), which is metabolized into [25(OH)D] (remember that for later) which is more like a hormone in structure, and then metabolized in your organs into a potent hormone [1,25(OH)2D]. It is also now known that vitamin D affects around 2000 genes (perspective: that’s about 10% of ‘em, which in the bio-geek world is huge) when previously it was only considered to affect the kidneys and blood phosphate and calcium levels. In other words, vitamin D—misnamed or not—is an over-achiever. An over-achiever that it is woefully under-present in most of us.

It is estimated that 80-90% of Americans are deficient in vitamin D. How was this arrived at, you ask? By examining dietary and environmental links to chronic diseases. Specifically, the higher incidence of cancers in those at living at higher latitudes and with lower sun exposure. “Current research has implicated vitamin D deficiency as a major factor in the pathology of at least 17 varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease, and more.” (Vitamin D Council)
While I’ll be getting to how vitamin D can put the mojo into your workouts, I think we can all agree that nothing throws a monkey wrench into a training schedule like one of those chronic illnesses just listed. The links between vitamin D and these problems are so strong, and the research is so copious now, that many experts, such as John Cannell, MD and others, aren’t just suggesting but screaming from the mountain tops that bazillions of dollars can be saved in chronic disease treatment alone by bringing peoples’ vitamin D levels up to snuff. Cannell, a researcher and vitamin D expert, even put this in the final slide of his renowned presentation on Vitamin D: “We don’t truly know the burden of chronic disease. And we won’t, until everyone has enough vitamin D”. Makes you think.

It’s no shocker that we don’t get enough of the stuff. We work in buildings with artificial (non-UV) light with windows that block UVB rays, we slather ourselves with full spectrum sunscreens and blocks, and we hide from the sun like it’s it the creature in a horror movie and we’re the screaming chick just two more strides from twisting her ankle. But I’m going to save most sun-related stuff for another post because it’s just that kind of topic, so you can get all up in my grill about it then. Rather, I’ll use it as a segue into athletic performance and vitamin D findings. So {segue!} it might interest you to know that Eastern European athletes used UV light as part of their training regimen. German literature documents this and that country’s athletes were certainly known for being dominant in world sports. (And I’m talking about the ones who passed the drug tests). Also, in one study, some Russian sprinters were treated with UV light, another group was not. Then both groups underwent identical training programs for the 100-meter dash. The control group improved their sprint times by 1.7 percent while the radiated ones lowered their times by 7.4 percent.
In a review of historical and current literature, it was concluded that “…[P]hysical and athletic performance is seasonal; it peaks when 25-hydroxy-vitamin D [25(OH)D] levels peak, declines as they decline, and reaches its nadir when 25(OH)D levels are at their lowest. Vitamin D also increases the size and number of Type II (fast twitch) muscle fibers.” And, in another article about vitamin D and athletic performance, its importance in the normal growth and development of muscle fibers and proper immune system functioning was highlighted. So, even if it isn’t cancer sidelining you (and I sincerely hope it never ever is), a bad case of the flu can be enough to keep you out of the game for a while. Harking back to vitamin D’s bone-building role, stress fractures are markedly reduced in those athletes with good vitamin D levels as well. Finally, I’d like to mention that several studies have “…also shown that, among athletes who train outside year-round, maximal oxygen intake tends to be highest in late summer…The athletes, in other words, are fittest in August, when ultraviolet radiation from the sun is near its zenith.” They go on to reveal that these athletes then experience sharp drops—as early as a month later—in maximal oxygen intake even when their training intensity remains the same. If you can get past the sun part for now, and realize they are looking at it from the athletes’ vitamin D production capability, you get the idea: low D = lowered performance.

So what’s an athlete to do in the middle of -8 degree Fahrenheit weather, knowing her summer vitamin-D stores are dwindling, and with no Spring in sight? You got it. Supplementation! If you’re thinking about banging down untold quantities of dairy, head over to last week’s “Truth or Dairy?” post, then come back (grabbing a big spinach salad on the way). And most fortified foods aren’t cutting it—the amount in it is often lower than what it contains, and even more often it’s not well absorbed. Plus, we’re whole food gals! “Fortified” food almost always means “processed” food. No thanks. Your first step is to get your vitamin D levels tested. Specifically you want to get your (remember from paragraph 2?) [25(OH)D] levels tested. Often your doc (for a lot of us this means our GYN) will add this to a blood draw. You can also order a test online if necessary at www.zrtlab.com. This is an imperative first step before supplementing with vitamin D so that you know: a) if you have an insufficiency or deficiency to begin with; b) how severe it is if the answer to “a” is yes; c) how much to supplement with; d) whether or not your supplementation is adequate with subsequent testing. Even if you are absolutely sure you need more vitamin D, your supplementation will be safer and much more meaningful overall if you do this. This is why I won’t continue with current research and opinions about dosage recommendations. For that you’ll need to wait for your results and for an upcoming Model Per4mance MP3 series, part of which will address that topic. {plug plug}

References:

Athletic performance and vitamin D. Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Med Sci Sports Exerc. 209 May;41(5):1102-10.

Phys Ed: Can Vitamin D Improve Your Athletic Performance? Reynolds, Gretchen. New York Times Well Blog, Sept 23, 2009. http://well.blogs.nytimes.com/2009/09/23/phys-ed-can-vitamin-d-improve-your-athletic-performance/

www.vitamindcouncil.org

Take Control of Your Health by Joseph Mercola, MD

Dark Deception by Joseph Mercola, MD

Tags: dairy, Health, supplementation, supplements, vitamin d