Vitamin D Insufficiency May Impair Athletic Performance
Almost every schoolchild knows that vitamin D – the "sunshine vitamin" – is important
for building strong bones. After all, for nearly five decades following its discovery,
scientists believed vitamin D was primarily involved in regulating calcium absorption
and maintaining skeletal health, and most people still think of it that way. Within
the last 40 years, however, researchers have learned that vitamin D behaves more
like a hormone than a vitamin, and scientists are currently exploring its roles
in electrolyte metabolism, protein synthesis, immunity, nerve and muscle function,
and an array of other physiologic processes.
Over 75 percent of Americans could be vitamin D "insufficient", meaning they get
enough vitamin D to avoid deficiency but not enough to maintain optimal healthy
levels. In elderly individuals, vitamin D insufficiency has been linked to muscular
weakness, poor balance, delayed reaction time, and a higher risk for falls and fractures.
A review in the May 2013 issue of Nutrients suggests that even mildly low vitamin
D levels can adversely affect young people, too, and such insufficiency could be
particularly consequential in athletes. According to Dana Storlie-Ogan, a nutritionist
at Central Washington University in Ellensburg, Washington, athletes who do not
get enough vitamin D might find their performance lagging, they may require longer
recovery times, and they could be more prone to stress fractures and muscle injuries.
Athletes who participate in indoor sports are especially likely to develop vitamin
D insufficiency.1
The average person needs at least 3,000 to 5,000 IU of vitamin D every day.2 Since
vitamin D participates in metabolic pathways that are "up-regulated" during exertion,
physically active people require more vitamin D for peak performance. Storlie-Ogan
advises athletes to have their vitamin D status evaluated and adjust their vitamin
D intake to maintain a serum 25(OH)D level above 40 ng/mL.