Thursday, June 4, 2009
Vitamin D and Athletic Performance
Greetings! ACSM was great and I am working on getting the info out to you soon. I am probably driving my poor web person batty as I am posting in a blog that will be transferred over to a new site soon. I am hoping to have it all up and running by the third week of June, so posting here may be a bit sparse in the cut over period; but fear not as I will have tons of killer new performance enhancement items for you soon.
Athletic Performance and Vitamin D
Something I have been following for some time now is the building research on Vitamin D. Vitamin is technically a hormone that does a myriad of functions in the body.
Vitamin D comes mainly from fatty, wild caught fish (hmmmmmm fresh sockeye salmon with some Cajun spice and a nice glass of Cabernet wine; oops back on track here) or your body can make it from sunlight (UVB) exposure. The downside for those that live in the northern climates like myself in Minnesota and my friends even further north in that tundra they call Canada, is that the amount of UVB during most of the year is not enough for adequate Vitamin D production.
What about muscle?
The cool part is that in research by Birge et al. in 1975 Vit D (in the 25 (OH)D form--the "natural" form in the body) has been shown to to directly increase protein synthesis (e.g. adding new muscle)
The optimal level in this study is quoted at 50 ng*ml-1 for 25 (OH)D levels. Since there is so much literature showing all the issues of Vitamin D deficiency, future trials may become more scarce since it could be argued that to have control or untreated Vit D group may be unethical!
How To Determine Levels?
Keep in mind I am not a medical doctor (although I did stay at a Holiday Inn recently), and I am only providing you the information to make an intelligent decision about your health and athletic performance. An option is to get your Vit D level tested through your local doc. If that is not an option, ZRT labs does Vit D testing by mail, so see the info below.
As a personal experiment of n=1 I will have my levels tested soon and keep you all updated on what I find.
Here is the abstract for you. For my newsletter friends, I will have an exclusive heads up on a video with tons of Vit D info out to you all soon.
Mike T Nelson
Athletic Performance and Vitamin D.
Medicine & Science in Sports & Exercise. 41(5):1102-1110, May 2009.
CANNELL, JOHN J. 1; HOLLIS, BRUCE W. 2; SORENSON, MARC B. 3; TAFT, TIMOTHY N. 4; ANDERSON, JOHN J. B. 5
Purpose: Activated vitamin D (calcitriol) is a pluripotent pleiotropic secosteroid hormone. As a steroid hormone, which regulates more than 1000 vitamin D-responsive human genes, calcitriol may influence athletic performance. Recent research indicates that intracellular calcitriol levels in numerous human tissues, including nerve and muscle tissue, are increased when inputs of its substrate, the prehormone vitamin D, are increased.
Methods: We reviewed the world's literature for evidence that vitamin D affects physical and athletic performance.
Results: Numerous studies, particularly in the German literature in the 1950s, show vitamin D- producing ultraviolet light improves athletic performance. Furthermore, a consistent literature indicates physical 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. Most cross- sectional studies show that 25(OH)D levels are directly associated with musculoskeletal performance in older individuals. Most randomized controlled trials, again mostly in older individuals, show that vitamin D improves physical performance.
Conclusions: Vitamin D may improve athletic performance in vitamin D-deficient athletes. Peak athletic performance may occur when 25(OH)D levels approach those obtained by natural, full-body, summer sun exposure, which is at least 50 ng[middle dot]mL-1. Such 25(OH)D levels may also protect the athlete from several acute and chronic medical conditions.