vitamin d and athletic performance: the potential role of muscle

vitamin d deficiency is a worldwide epidemic, with well known impacts on calcium metabolism and bone health, but increasingly recognized associations with chronic health problems such as bowel and colonic cancer, arthritis, diabetes and cardiovascular disease. in recent years in the sports medicine literature, there has been an increased focus on the potential impact that inadequate vitamin d levels may have on athletic performance. in the early 20th century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and while remaining limited, evidence is accumulating to support this view. muscle structure and function is recognised to play a key role in athletic performance, and both cross-sectional and longitudinal studies allude to a functional role for vitamin d in muscle. the identification of the vitamin d receptor in muscle tissue provides a direct pathway for vitamin d to impact upon skeletal muscle structure and function. this review focuses on the current understanding of the action of vitamin d within skeletal muscle tissue, and the potential impact on performance.