Wyon, Wolman, Nevill, Cloak, Metros, Gould, Ingham, Koutedakis; Clin Sport Med, Volume 26, Number 4, July 2016
Indoor athletes and those residing in Northern Climates have been regularly shown to have Vit D deficiency due to decreased sun exposure. There has been a link confirmed between muscle function and synthesis of predominantly Type 2 muscle fibres and Vit D which binds to the muscle’s nuclear hormone receptor. The evidence supporting reduced fall risk in the elderly with Vit D supplementation is clear and we often recommend Vit D supplementation to all of our elderly patients. Should we do the same to our young athletes in our practice?
Previous long term studies have shown an increase in strength and power as well as injury reduction over a 4-month period of 2000 IU/day oral Vit D3 supplementation. In this study, a one time dose of 150,000 IU PO Vit D3 bolus was given to athletes after testing muscle strength. The testing was repeated 8 days later and confounding variables and exclusion criteria were accounted for. The results showed an increase of 13% strength in the treatment group and a 3% increase in the placebo group after 1 week. Most benefits in strength and power were seen in those athletes with pre-treatment low levels of Vit D3.
Although more studies are needed to address dosing and long term effect of Vit D supplementation on performance, this study seems to point out the importance of tracking Vit D levels in our athletes over the winter months and consider supplementing to attain risk-free optimization. We do encourage Vit D3 supplementation in our elderly, perhaps it’s time we encourage our young athletes to supplement with Vit D3 through the long Canadian winters.
Keith Morgan MD, CCFP, Fellow in Sport and Exercise Medicine. U Ottawa
Advisor Dr. Taryn Taylor BKin, MSc, MD, CCFP (SEM), Dip Sport & Exercise Medicine