I am a college-level athlete (women’s basketball). I’ve started taking some supplements my Mom sent me but I also saw some stuff on the Web that says what I really need is Vitamin D3 (not D2) even if I am young and healthy. I don’t want to pollute my body with anything (including vitamins) without knowing they are helping. Do you have any advise on this?

You wouldn’t think athletes with their strong bones and muscles would need any Vitamin D supplementation. But according to a recent report, there are sports health benefits to taking Vitamin D supplements. Some of those benefits actually come in the form of prevention. That is — preventing the musculoskeletal events that can occur when someone is Vitamin D deficient (e.g., bone fractures, musculoskeletal pain, frequent illness).

Vitamin D is made in the body when the skin is exposed to ultraviolet B rays from the sun. But fears about skin cancer have reduced sun exposure through the use of sunscreen products. People living in certain (Northern) regions of the globe don’t receive enough of the essential sun rays even without sunscreen.

Because very little Vitamin D comes from natural food sources, some products like cereals and milk are Vitamin D fortified. But even with these dietary sources, most people (children and adults) are considered Vitamin D deficient and in need of supplementation. Athletes and sports participants are no exception. In the report we referred to, results of studies suggest the following for athletes:

  • Indoor athletes do need more Vitamin D supplementation than outdoor sports participants. BUT outdoor athletes must be aware of seasonal differences in sun exposure and supplement accordingly.
  • Outdoor athletes should have their blood tested in early autumn to adjust for seasonal differences in sun exposure.
  • There is no extra advantage of having a blood value of more than 50 ng/mL of vitamin stores in the body.
  • Differences in skin pigmentation must be taken into consideration. African Americans (and other dark-skinned individuals) need up to ten times more sun exposure to reach the same levels of Vitamin D in the body compared with Caucasian or light-skinned athletes.
  • The athlete who is tested as Vitamin D deficient (less than 30 ng/mL of 25(OH)D — the measure used to assess blood levels) should take 50,000 IU of Vitamin D3 each week for eight weeks or until blood tests show a steady level of at least 25(OH)D.
  • Sunshine is still nature’s perfect solution to strong muscles, teeth, and bones. Adequate exposure to ultraviolet rays that stimulate production of Vitamin D in the body avoid any excess accumulation or toxicity in the body. That’s because the body has special feedback loop to prevent this negative effect.

    Research has not been done to show what blood levels of Vitamin D are linked with optimal sports performance for each individual athlete. As mentioned, exceeding 50 ng/mL doesn’t seem to provide any additional benefit. We do know that performance is enhanced by exposure to ultraviolet rays. Studies from more than 50 years ago showed less pain with sports injuries, improved reaction times, faster speeds, and greater endurance in athletes with adequate vitamin stores in the body.

    Likewise, it is clear that the effects of too-low levels of Vitamin D include severe muscle weakness, loss of muscle tone, generalized body pain, increased falls, and bone deformities. Athletes who have enough Vitamin D have fewer colds and flus. And you may find the added benefit of faster recovery from inflammation after bouts of overtraining.

    The best approach may be to talk with your team physician about your concerns. A blood test can establish your baseline level of Vitamin D. Any supplementation should be done under your physician’s direct supervision.