Effect of vitamin D supplementation in winter on physical performance of university students: a one-month randomized controlled trial.

Background: There is epidemiological evidence which suggests an association between 25-hydroxyvitamin D [25(OH)D] levels and bone and muscle function; however, it is unclear whether vitamin D supplementation has an added benefit beyond bone health. Here, we investigated the effects of vitamin D supplementation (1 month) on physical performance in Chinese university students in winter.

Methods: One hundred and seventeen eligible subjects with 25(OH)D (19.