Two Wheel Blogs

Among many other things, vitamin D is a potent hormone steroid. That means it's effects could be similar to other types of steroids which athletes have used (illegally). There have been reports that athletes who do indoor sports and take vitamin D have increased abilities (see this newsletter from the vitamin D council). As suggested by Dr. Holik, those living above the latitude of approximately Atlanta Georgia will most likely be suffering from a vitamin D deficiency in the winter. Even if you are braving the cold and riding outside, the angle of the rays of the sun are insufficient to produce vitamin D in your skin and you will still very likely be deficient. Could this be a factor in your loss of power during the winter?

Dr. John Cannell is a psychiatrist who has been investigating vitamin D and mental illness. There is compelling evidence that vitamin D deficiency could be a factor in depression (read Dr. Cannell's thoughts on this). In veiw of this, I wonder if it could also lead to increased perceived exertion during the winter?

These are interesting questions. But it will take some research to find out for sure. Perhaps some enterprising grad student will look into this. Or some research scientist. But you can still do your own small scale research. Start taking vitamin D or get yourself a UVB lamp. We are entering the winter months when vitamin D deficiency will be taking hold. Get your vit D levels up to par and see if it makes a difference in your training. Besides this, vitamin D also increases innate immunity and it is very likely that it will keep you from getting the flu more successfully than a flu shot too.

How much to take? If you use a UVB lamp, it's no problem, just sit under it a couple times per week for 15 minutes or so and your body will automatically regulate the proper amount. If you don't have a lamp or find it inconvenient, use vitamin D3 supplements. It is hard to find supplements which have the amounts suggested by Holick and Cannell. Doubling up on your multi (which most likely contains 400 IU of vit D) is not a good idea because the vitamin A in it will cause problems and compete with the vitamin D. Searching some of the online venders (such as Vitamin Shoppe) should yield some results.

A note for reference: I am not a nutritionist or doctor so read the links I provided for expert information.