Vitamin D and muscle performance in athletes

Vitamin D supplementation has recently gained considerable attention in the sports community as a potential nutritional treatment to enhance athletic performance. Interest in vitamin D supplementation for athletes stems in part from intriguing preclinical studies of vitamin D actions on key muscle biological pathways and from data on muscle performance enhancements in older non-athletic adults. Multiple observational studies in young athletes report a direct association between vitamin D status and muscle strength, power, and recovery from musculoskeletal injury. Yet, clinical trials examining the musculoskeletal responses to supplementation with vitamin D in athletes are limited and report mixed results due in part to small sample size and differences in study design, population, and vitamin D dose. Based on meta-analyses in non-athletic populations, future clinical trials to determine the impact on athletic performance should be conducted in large samples of athletes with undisputed vitamin D deficiency at baseline.