Research on Vitamin D demonstrates its role in bone health, immune function, and impact on performance. A large number of studies have showcased that athletes with suboptimal vitamin D levels may not perform their best.
A study on basketball players attending the NBA combine found 32% of athletes to be deficient and 47% to be insufficient in vitamin D. In a study on football players attending the NFL combine, inadequate vitamin D was present in 59% of participants. Players with a history of lower extremity muscle strain and core muscle injury had a higher prevalence of inadequate vitamin D. (2)
Not only is vitamin D important for bone health and preventing stress fractures, but it also influences muscle function. A study on elite ballet dancers found that dancers who supplemented with 2000 IU/day vitamin D had increased isometric strength (18.7%) and improvements in vertical jump (7% higher). The dancers who were receiving supplementation. The supplemented group also sustained significantly less injuries than the control (not supplemented group) during the study period. (1)
Along with potential performance “benefits”, vitamin D also plays a role in supporting a healthy immune system. Athletes with heavy training volumes and higher intensities have higher demands on their immune systems and a larger need to support healthy immune function. (3)
Many healthcare professionals' recommendations are to consume 1000 IU/day, and adults aged 19-50 to consume at least 1500-2000 IU/day in addition to sensible sun exposure to maintain optimal levels. 🌞
Beef liver, salmon, and egg yolks are some whole food sources of vitamin D, with one egg yolk containing about 44 IU. Vitamin D is also fortified to beverages like milk, non-dairy milk alternatives, and some fruit juices and cereals.
I take Thorne Research liquid Vitamin D daily, with a meal- especially as we enter the winter months!
References:
1. Wyon, M. A., Koutedakis, Y., Wolman, R., Nevill, A. M., & Allen, N. (2014, January). The influence of winter vitamin D supplementation on muscle function and injury occurrence in elite ballet dancers: a controlled study. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/23619160'
2. Rebolledo, B. J., Bernard, J. A., Werner, B. C., Finlay, A. K., Nwachukwu, B. U., Dare, D. M., … Rodeo, S. A. (2018, April). The Association of Vitamin D Status in Lower Extremity Muscle Strains and Core Muscle Injuries at the National Football League Combine. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/29275983
3. Ogan, D., & Pritchett, K. (2013, May 28). Vitamin D and the athlete: risks, recommendations, and benefits. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3725481/