When it comes to sports and improving athletic performance, people will do anything. From football players drinking pickle juice to distance runners supplementing with alcohol during a race, performance "enhancers" have been around for a very long time. Romans and Greek Olympians would ingest deer liver and lion heard to gain an edge on their competition for the Olympic Games and other physically demanding tasks (Applegate & Grivetti, 1997). Although supplementation and substance use has been around for an extended period of time, the substances and supplements themselves have changes vastly over the course of time. Performance enhancers like wheat germ oil, ginseng, and gelatin have all come and gone as popular fads of the past. Substances popular today may not be popular in the future, so how can we decide what works and what doesn't? There has been a lot of discussion about the health benefits and improvements in athletic performance associated with supplementation of Vitamin D. This research has created much debate over whether or not Vitamin D plays a role in athletic performance in sport.
Vitamin D can be classified not only as a vitamin, but as a steroid, acting through different various pathways throughout the body (Chalabi & Hamilton, 2010). It can be brought into the body by one of two ways. Either it is ingested by eating foods like fortified cereals, oily fish, egg yolk, and some types of yeast products, or it can be synthesized in the skin by the UV rays from the sun (Chalabi & Hamilton, 2010). Living in the northern part of the Midwest and receiving direct sunlight only 4-5 months out of the year, one has to wonder how prone we are to Vitamin D deficiency. For those who live in a climate where sunlight is available year round, Vitamin D absorption rates are higher because of their exposure to the sun. We are obviously at a large disadvantage living in a colder 4-season climate, but with proper supplementation, can achieve the same levels of Vitamin D as those who live in warmer environments.
Sport performance is a good indicator of body type and composition, especially in the musculoskeletal system. Vitamin D has been shown to play very important roles in the serum levels of calcium and phosphorus, two very important minerals needed for the development of bone. A deficiency in this vitamin has been liked to many deficiency problems like osteopenia, osteoporosis, and osteomalacia (Chalabi & Hamilton, 2010). Healthy bone and vitamin maintenance are large indicators of sport performance, and when these requirements are not met, they lead to increased injury and stress fractures (Larson-Meyer, Peterson, & Willis, 2008). These types of deficiencies not only affect athletic and sport performance, but also daily life activities. Vitamin D may be more than a sport enhancement supplement; it may actually be an overall health enhancer too. Although the research is promising, do not run with your inhibitions yet, more research is still needed in order to quantify just how important this vitamin is. It may be another fad in the field of sport performance, or it may be the missing tool to a perfect nutrition diet of an athlete. Only time will tell what is right and what is wrong..
References:
Applegate, E. A. & Grivetti, L. E. (1997). Search for the competitive edge: A history of dietary fads and supplements. Journal of Nutrition, 127, 869-873.
Chalabi, H. & B. Hamilton (2010). Vitamin D: An update for the sports medicine practitioner. Sports Medicine, 43, 11-16.
Larson-Meyer, D. E., Peterson, N. J., & Willis, K. S. (2008). Should we be concerned about the vitamin D status of athletes? International Journal of Sport Nutrition and Exercise Metabolism, 18, 204-224.
When have distance runners ever supplemented with alcohol during a race?
How can vitamin D be considered a steroid?
From what I know, I would not consider vitamin D a performance enhancer but just a vitamin. Vitamins and minerals are necessary for the human body to function properly. I am really interested in the topic, but I am left with more questions than answers.
It's easy for people to believe that just because we live in a climate that is not warm, that we don't get enough vitamin D from sunlight. On average 10-15 minutes in the sun is sufficient. In the summer, spend a little time outside to get that vitamin D. But in the winter, if you eat eggs, fish, or a variety of other fortified foods, you should be fine. You only need 400-2000 IU of Vitamin D a day. Salmon alone has 360 IU. I know vitamin D is important to the diet and healthy living, but I've never heard anything about athletic performance benefits.