Vitamin D supplementation is important in military research because of its role in musculoskeletal health.
This systematic review examined the effects of vitamin D supplementation on serum 25-hydroxyvitamin D (25(OH)D) concentrations and musculoskeletal health outcomes in military personnel.
A comprehensive search was conducted using MEDLINE, EMBASE, CINAHL, SportDiscus, and the Cochrane Library databases and the reference lists of existing review articles and relevant studies.
Reviewers independently screened titles, abstracts, and full texts of the articles using predefined criteria.
Systematic review of randomized controlled trials (RCTs) using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement.
Level of Evidence:
Three reviewers independently extracted data and assessed the methodological quality. Mean differences with 95% CI in serum 25(OH)D concentrations between the vitamin D and placebo arms were calculated.
Four RCTs were included in the qualitative analyses. The 25(OH)D concentrations were improved with 2000 IU/d supplementation (mean difference, 3.90 ng/mL; 95% CI, 0.22-7.58). A trial on female Navy recruits showed a significant decrease in stress fractures (risk ratio, 0.77; 95% CI, 0.62-0.95), particularly tibial fractures, from daily supplementation of 800 IU vitamin D and 2000 mg calcium.
There was a positive trend in 25(OH)D concentrations from higher doses of supplementary vitamin D in military submariners and a possible benefit to bone health when vitamin D was combined with calcium.