Efficacy of Vitamin D Supplementation in Physical Performance of Iranian Elite Athletes.

However, a growing body of evidence has suggested a wide variety of other functions for vitamin D in the body, including immune regulation, protein synthesis, inflammatory response, cell growth, and skeletal muscle strength and function.[ 1 ] The possible relationship between vitamin D and physical function was known many years ago when seasonality of athletic performance was observed, that is, the performance was commonly better in late summer, whereas it had a decreasing trend in winter.[ 2 ] Because of this observation, ultraviolet (UV) irradiation was used to improve physical performance in a group of medical students.[ 3 ] Vitamin D has two main isoforms, D 2 or ergocalciferol, which is found in plant dietary sources, and D 3 or cholecalciferol, which is synthesized in skin upon direct exposure to solar beam.

also in 47,180 other papers