Vitamin D may improve exercise performance and lower risk of heart disease

Taking vitamin D supplements can improve exercise performance and lower the risk of heart disease, according to the findings of a preliminary study presented this week at the Society for Endocrinology annual conference in Edinburgh. Previous studies suggest that vitamin D can block the action of enzyme 11-βHSD1, which is needed to make the "stress hormone" cortisol. High levels of cortisol may raise blood pressure by restricting arteries, narrowing blood vessels and stimulating the kidneys to retain water. As Vitamin D may reduce circulating levels of cortisol, it could theoretically improve exercise performance and lower cardiovascular risk factors.