Runner's Corner

November 2009 : Vitamin D

Revisit Vitamin D and Boost Your Performance

November Runner’s Corner

Kitty A. Consolo, Ph.D.

          I’ve written about the importance of vitamin D before in the October 2008 Runner’s Corner on nutrients.  However there is now some new research I want to share with you that can boost your running performance regarding vitamin D.

How to Know if You are Deficient

          You won’t be able to feel any signs you are deficient other than possibly suffering a bone fracture  and muscle soreness which doesn’t always occur.  The best way to know your vitamin D levels is to ask your doctor to order a blood test.  Recent research from Garland, Grant, Mohr, Gorham and Garland, 2007, suggests that keeping blood or serum D levels above 52 ng/mL can potentially lower breast cancer by 50% as well as colon cancers.  This is higher than original clinical research that suggested one be above 31ng/mL. 

How much D to take?

          While one’s body can make vitamin D through 20 minutes of sun exposure three days a week, if you live in the Northern half of the US (like Ohio), from October to April, the sun’s angle does not deliver adequate rays to produce enough D from the sun.  Furthermore, as one ages, one’s skin does not produce the same amount of D.  Hence to ensure a blood level of 52ng/mL or higher, the above researchers as well as vitamin expert Dr. Holick, professor of Medicine at Boston University School of Medicine and director of his own vitamin D lab recommend a daily intake of 2000IUs.  The best form to take is D3.  I personally take D3 made by Solgar and order it through Luckyvitamin.com. I order the 600 IUs and take 4 a day which has increased by blood D levels to the 50ng/mL amount.  I tried lower doses and sun exposure and could not get my level up.  The toxic level of D would be 10,000 IUs so even though 2000IUs sounds like a lot, it is well below a toxic level.  (note I do not receive any money or promotional benefits from mentioning Solgar or luckyvitamin.com).

New Vitamin D benefits

          Researchers in the February 2009 Journal of Clinical Endocrinology and Metabolism, found that higher levels of D in adolescents resulted in their ability to jump higher, with greater power and quicker than those with lower D levels.  Other research in the December 2008 issue of Molecular Aspects of Medicine, found that vitamin D increases the size of fast-twitch muscles and muscle strength which could be useful for shorter running distance such as the mile and 5km.  And vitamin D is already known for its role in bone health, without adequate levels of D, calcium which is also critical for bone, can not be absorbed well.  In fact, Olympic hopeful Deena Kastor suffered a bone fracture 3 miles into the Beijing Olympic marathon due to a vitamin D deficiency.  Vitamin D may also help mood, prevent injuries and promote muscle recovery.

Summary

          As we head into the next six months of limited sunlight and rays, consider having your blood D levels checked and then take a supplement of D3.  Having adequate D can reduce not only cancer risk, but strengthen your bones, muscles and running performance.

I look forward to seeing you on the roads.

Reference on D

Garland, C., Grant, W., Mohr, S.,  Gorham, E., and Garland, F. (2007). What is the dose-response relationship between vitamin D and cancer.  Nutrition Reviews,  65, S91-97.

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