The Impact of Vitamin D

Spending some time outside in the sun may seem like an odd recommendation for a hockey team, but that’s just what the sports dietitian ordered for the Detroit Red Wings. The Red Wings are among many squads that are focusing on vitamin D levels--thus prompting the team's sports dietician to suggest players spend time outside when they go to California for games.

According to an article from the Wall Street Journal, monitoring vitamin D levels in elite athletes has become more prevalent thanks to research indicating that a deficiency may be related to an increased risk of injury. There have only been a handful of studies focusing on elite athletes, but the collective results indicate a possible relationship between muscle and bone injuries and vitamin D deficiency.

“You can’t draw a definitive conclusion,” Pittsburgh Steelers team physician, and co-author on a study on the Pittsburgh Steelers and vitamin D levels, Mark Duca told the Wall Street Journal. “But it certainly piques our interest, particularly in a violent contact sport like football.”

A recent review of seven trials has found that vitamin D supplementation can significantly increase strength in lower and upper limbs. Published in the Journal of Science and Medicine in Sport, the review was conducted by researchers at Queen Mary University of London and included data from 310 adults between 21 and 31 years of age.

As reported at, the trials spanned four to six months and used doses of 4,000 IU per day to 60,000 IU per week. Two studies showed the most significant results, with dosages between 14,000 IU and 60,000 IU per week for four to six months.

“This review has found that vitamin D3 supplementation improves upper and lower limb muscle and strength in a healthy, adult, athletic and non-athletic population between the ages of 18 and 40,” the authors of the study wrote.

Much of the previous research on vitamin D supplementation has focused on muscle strength in already compromised individuals like the elderly. Researchers hope that this new summary of the impact of vitamin D on healthy adults will lead to more studies on the effects of the vitamin on muscle power and endurance.

Along with spending time in the sun to allow their bodies to produce Vitamin D, athletes can get the nutrient through fish and eggs, fortified foods such as milk and some cereals, and supplements. Sports dieticians say athletes should get at least 1,000 to 2,000 international units of vitamin D daily, whether it’s through their food or supplements.