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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Vitamin D supplementation in collegiate swimmers and divers

Who remembers Bob Beamon? Back in 1968, Bob Beamon set the world record in the long jump at the Mexico City Summer Olympics. He bested the existing record by almost 2 feet. Unlike all other Olympics from the mid-50s to the mid-80s, athletes had to come early to Mexico City early to get acclimatized to the 7,000 foot altitude. In doing so, the outdoor athletes from around the world soaked up the vitamin D producing sunlight. Do you remember how many world records (all in outdoor sports) were set in Mexico City?

Mexico City was the only year in almost 3 decades that the Russians and East Germans did not dominate the summer Olympics. It’s my theory that unlike the Olympics ten years before and twenty years after the 1968 Mexico City games, Russia and East Germany did not compete against vitamin D deficient athletes in Mexico City. The Russians and East Germans used UVB sunlamps from around 1956 to about 1984. They were used to competing against vitamin D deficient athletes, but they met vitamin D sufficient athletes in Mexico City. The Russians and East Germans came in fifth and sixth.

I used to write a lot about vitamin D and athletes. I thought it would trigger interest in vitamin D. You have to open the hyperlink below then search for the title of each newsletter.

Cannell JJ.  Peak Athletic Performance and Vitamin D. The Vitamin D Newsletter, March 2007.

Cannell JJ.  Why Athletic Performance Matters. The Vitamin D Newsletter March 2007 Supplement March 2007.

As I reported, it may have been the reason the Chicago Blackhawks went from last to the winning Stanley Cup in 2010.

Cannell JJ.  Vitamin D and the Chicago Blackhawks.  The Vitamin D Newsletter May 2010.

Then I wrote a paper about it.

Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.

Then I wrote a book about it.

Cannell JJ. Athletes Edge, faster, quicker and stronger with vitamin D.

I am glad to see all the recent interest in vitamin D and athletics. Recently, Doctor Regina Lewis working with senior author Doctor Travis Thomas, studied swimmers and divers at the University of Kentucky, which sits at a latitude of 38 degrees.

Lewis RM, Redzic M, Thomas DT.  The Effects of Season-Long Vitamin D Supplementation on Collegiate Swimmers and Divers. Int J Sport Nutr Exerc Metab. 2013 Mar 8.

They randomized 32 athletes to take either vitamin D or placebo. At baseline, apparently they already had spent much of the summer outside. I say this because mean baseline 25(OH)D levels were 57 ng/ml.

They gave 19 of the swimmers 4,000 IU/day during the winter and the rest got placebo. Four thousand units a day kept almost all athletes above 32 ng/ml during the Kentucky winter. The placebo athletes lost 20 ng/ml of their 25(OH)D, going from 65 to 45 ng/ml.

They found that that mineral-free lean mass were positively associated with 25(OH)D in men (p=0.04). In women, femoral neck bone mineral density was positively correlated with 25(OH)D (p=0.02). Neither illness nor injury were related to 25(OH)D; however, 77% of injuries coincided with wintertime decreases in 25(OH)D.

The authors concluded:

“This study indicates that vitamin D supplementation was effective at increasing 25(OH)D in athletes who primarily trained and competed indoors. We found that 25(OH)D was associated with increased mineral free lean mass in men and increased bone mass in the proximal dual femur in both sexes. Although not significant, we also observed a greater number of injuries as 25(OH)D concentrations decreased.”

Further, they recommended,

“Future randomized controlled trials should recruit larger athletic samples to assess the “cause and effect” of vitamin D supplementation on bone, muscle, inflammation, and incidence of injury. Continuing clinical trials addressing the impact of vitamin D on athletes will help to expand our knowledge of the most advantageous 25(OH)D concentration needed to promote optimal health in athletes. Sufficient vitamin D supplementation could prove to be an easy and affordable method to preserve bone, decrease risk of injury and maintain 25(OH)D.”


  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

One Response to Vitamin D supplementation in collegiate swimmers and divers

  1. Rita and Misty says:

    I wonder how many university level coaches are vitamin d intelligent? High school coaches and athletic departments as well….

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