Soak Up Some Vitamin D

Vitamin D is an essential fat-soluble vitamin that is associated with bone health, optimal calcium absorption, healthy immune function and optimal muscle function. For athletes, that is enhancing adaptive response to exercise, decreasing stress fractures and upper respiratory symptoms, which all help an athlete stay healthy and maintain optimal performance. 

Vitamin D is mainly obtained through sun exposure and a small amount through diet and supplementation. Vitamin D-rich foods include egg yolks, fatty fish like salmon, tuna and trout, and liver. Some other foods, like milk, cereal and bread, often have added vitamin D. There’s evidence for deficiency in some athletes, particularly in the winter with decreased skin sunlight exposure. The supplementation forms are Vitamin D2 and D3. Vitamin D3 is more potent in raising and maintain serum 25 [OH]D concentrations and stores in the body more than Vitamin D2. 

Vitamin D status should be measured to determine deficiency and insufficiency. Vitamin D deficiency can result from limited sunlight exposure, inefficient production in the skin, inadequate dietary intake, medication interfering with absorption and conversion of vitamin D, malabsorption syndromes, and liver, kidney or gastrointestinal disorders (e.g., Crohn’s disease).  Populations that may need extra vitamin D are older adults, breast-fed infants, athletes, people with dark skin, those living or training at northern latitudes, athletes in winter or indoor sports, and those with low or high body fat levels.

Supplementation between 600-2000 IU/day is recommended to maintain status for the general population. Supplementation guidelines are not yet established in athletes. For athletic populations, research has shown supplementation of 2000-4000 IU/day to be beneficial. Consult with your health care provider to check vitamin D status and consult a dietitian to see how much you should take.