Relationship between 25-hydoxyvitamin D, muscle strength, and incidence of injury in healthy adults: a systematic review.

The purpose of this systematic review is to answer the following clinical questions in healthy adults: is vitamin D status related to (1) muscle strength? (2) or incidence of injury? A literature search was performed using Pubmed, SPORTDiscus, and Web of Science to capture relevant articles that have examined these outcomes. Inclusion criteria required studies to address at least one of the 2 questions stated above, enroll healthy human subjects with a mean age of 18 to 65 years of age, and include serum 25-hydoxyvitamin D measures. Study characteristics such as vitamin D status, study design, and study population were documented.

The effects of season-long vitamin D supplementation on collegiate swimmers and divers.

The purpose of this 6-month randomized, placebo-controlled trial was to determine the effect of season-long (September-March) vitamin D supplementation on changes in vitamin D status, which is measured as 25(OH) D, body composition, inflammation, and frequency of illness and injury. Forty-five male and female athletes were randomized to 4,000 IU vitamin D (n = 23) or placebo (n = 22). Bone turnover markers (NTx and BSAP), 25(OH)D, and inflammatory cytokines (TNF-alpha, IL-6, and IL1-β) were measured at baseline, midpoint, and endpoint.