The Role of Vitamin D in Athletes: Performance and Injuries.
A Vitamin is an organic compounds found in food ranging from trace to small amounts, are essential for growth and health. Vita D is the only vitamin among all; of which human requirements can be met entirely through exposure to sunlight.
The ultra-violet (UV-B) rays convert the vitamin D precursors in the skin to D3. Vitamin D obtained from this process and obtained from the diet are converted to its storage form, 25 (OH) D.
Levels of Vitamin D vary in the general population, but in athletes, the level varies by season, training location, sport and the color of skin. Athletes who choose to train indoors and at higher altitudes have lower levels in comparison to athletes choosing to train outdoors and lower altitudes.
Vitamin D status is also lower in winter months and areas that have less sunshine hours. For example, for athletes training in a city like Bengaluru, the best months to train is from January to beginning of May. March being the sunniest month throughout the year. The months’ following May until September receives the least amount of sunshine with July receiving the lowest average sunshine in a year.
Research provides long standing evidence that Vitamin D status is important for bone health and prevention of bony injury in athletic population. The risk of stress fracture increases over by 4 times in athletes and runners who have vitamin D levels below 30 ng/ml. Low vitamin D levels may also impair muscle strength at contraction resulting in decreased performance and delayed recovery.
Prolonged low levels of vitamin D also have a deteriorating effect on the immune system leading to an increase susceptibility of upper respiratory infection in especially runners.
How to safeguard yourself from this silent but serious problem?
- Consult a Sports medicine expert. Take a blood test before you start a training program.
- Adjust your training load and volume based on your vitamin D levels and recommendation
from your sports physician.
- Train outdoors, so that you replenish what you lose during training.
- Calcium and vitamin D3 Supplementation during the winter months / indoor training
- Eat and maintain a healthy balanced diet.
- Peri and post menopausal women must consult a sports physician or Gynecologist for review of their hormonal status and serum calcium levels.
If you have a history of stress fracture, it is important to get a thorough evaluation.
However it is also important to be mindful of self-prescribing vitamin D supplements without professional opinion, as it can lead to vitamin D toxicity. Vitamin D toxicity although rare, can manifest in the form of hyper-calcemia (increased levels of calcium) leading to symptoms like anorexia, frequent urination, thirst, nausea, vomiting and in the most severe cases kidney dysfunction.
Dr. Atwar Hussain,
M.B.B.S, Msc. SEM (UK) ,Dip. SEM(IOC)
Dip. SEM (FIFA).
Sports and Exercise Physician