VITAMIN D

AVOID ILLNESS

As we enter the winter months, there’s ample evidence as to why triathletes in particular should stay supplemented (sunshine is the best form and we can’t get enough from food alone). A low vitamin-D level has been associated with a higher prevalence of respiratory illness in athletes. A study in 2016 (He. CS et al, Exercise Immunity Review) demonstrated that aiming for vitamin-D levels of above 75 nmol/l potentially prevented upper respiratory tract infections but also enhanced innate immunity.

PERFORMANCE

Since then, further studies have been conducted and research published in October 2018 showed that higher levels of vitamin D were associated with better exercise capacity. Each 10 nmol/L increase in vitamin D was associated with a statistically significant 0.78 mL/kg/min increase in VO2 max. While it was noted this was an observational study, the association was strong, incremental, and consistent across all the groups investigated. This suggests that there is a robust connection and provides further impetus for having adequate vitamin-D levels.