Vitamin D3, contrary to what its name suggests, acts more like a hormone than a vitamin. It circulates around our blood, and is involved in a huge number of physiological processes. It has the ability to act on virtually every tissue in the body (1). Our knowledge and understanding of the complex role it plays in health is still being discovered. However, its functions notably include immune response, hormone regulation, cell growth and more. The fact that vitamin D is capable of influencing so many tissues in the body, demonstrates its diversity and importance in maintaining general health.
As an athlete, whether professional or just recreational, vitamin D is not only important in maintaining overall health, but it also has beneficial effects on performance too. Peak athletic performance and trainability have been shown to occur during the warmer months, when there is more sunlight, and subsequently more vitamin D synthesis in our skin.
However, most likely due to the indoor setting of the sport, up to 94% of elite basketball players (2) and 83% of professional gymnasts (3) have been shown to have some level of vitamin D deficiency.
Surprisingly though, another study showed that 81% of the New York Giants football team were also deficient (4) – amazing when you consider how much outdoor training, and subsequent sun exposure these athletes get.
These somewhat surprising results reflect the importance of obtaining vitamin D through a combination of sunlight, food and supplementation. By supplementing with vitamin D, these athletes could see a positive impact on their performance.
Here are four ways vitamin D can improve your athletic performance.
INCREASE FAST-TWITCH MUSCLE FIBERS
It has been shown that vitamin D can increase both the size and number of fast-twitch muscle fibers (5). Fast-twitch muscle fibers help with explosive anaerobic movements such as weightlifting, or short sprints.
This was corroborated during a UK-based experiment performed on athletes, in which one group was given 5000IU of vitamin D every day for 8 weeks whilst the other group was given placebo. The group supplementing showed significant increases in their vertical jump ability, as well as their 100m-sprint time. (6)
BOOST ENERGY, EXERCISE LONGER
Vitamin D also improves phosphocreatine recovery time, which improves high-intensity exercise performance. (7) Phosphocreatine acts as a rapidly available source of energy for both muscle and brain tissues. This translates into more available energy for your workout, and improved endurance capabilities.
Want to gain muscle? Some studies suggest that the expression of the vitamin D receptor (the protein on the surface of cells to which vitamin D binds) is expressed on muscle fibers. This suggests vitamin D has a role in the regulation of muscle cell size and proliferation (8). It has also been indicated that healthy vitamin D levels are positively associated with muscle strength. (9) Studies also suggest that people with low vitamin D – blood serum levels below 30 nmol/l – have decreased strength, weakness and muscle wasting. (10) Make sure you’re getting adequate vitamin D to maintain, and even grow muscle mass.
KEEP BONES STRONG
One of the most well documented benefits of vitamin D is its synergetic effect with calcium. Vitamin D helps maintain strong, healthy bones, by improving the intestinal absorption of calcium. If you are physically active, this is particularly important, as vitamin D can reduce the risk of a stress fracture whilst exercising. (11)
1. Holick, Michael F. “The vitamin D epidemic and its health consequences.” The Journal of nutrition 135.11 (2005): 2739S-2748S.
2. Lovell, Greg. “Vitamin D status of females in an elite gymnastics program.” Clinical Journal of Sport Medicine 18.2 (2008): 159-161.
3. Willis, Kentz S., Nikki J. Peterson, and D. Enette Larson-Meyer. “Should we be concerned about the vitamin D status of athletes?.” International journal of sport nutrition and exercise metabolism 18.2 (2008): 204.
4. Shindle, Michael K., et al. “Vitamin D Status in a Professional American Football Team: 2008: Board# 203 June 2 9: 00 AM-10: 30 AM.” Medicine & Science in Sports & Exercise 43.5 (2011): 511.
5. Cannell, JOHN J., et al. “Athletic performance and vitamin D.” Med Sci Sports Exerc 41.5 (2009): 1102-10.
6. Close, G. L., et al. “Assessment of vitamin D concentration in non-supplemented professional athletes and healthy adults during the winter months in the UK: implications for skeletal muscle function.” Journal of sports sciences 31.4 (2013): 344-353.
7. Sinha, Akash, et al. “Improving the vitamin D status of vitamin D deficient adults is associated with improved mitochondrial oxidative function in skeletal muscle.” The Journal of Clinical Endocrinology & Metabolism 98.3 (2013): E509-E513.
8. Wagatsuma, Akira, and Kunihiro Sakuma. “Vitamin D signaling in myogenesis: potential for treatment of sarcopenia.”
9. Ceglia, Lisa. “Vitamin D and skeletal muscle tissue and function.” Molecular aspects of medicine 29.6 (2008): 407-414.
10. Pfeifer, M., B. Begerow, and H. W. Minne. “Vitamin D and muscle function.” Osteoporosis International 13.3 (2002): 187-194.
11. Dao, Dyda, et al. “Serum 25-Hydroxyvitamin D Levels and Stress Fractures in Military Personnel A Systematic Review and Meta-analysis.” The American Journal of Sports Medicine (2014): 0363546514555971.