Vitamin D in Basketball Players: Current Evidence and Future Directions

Abstract

Context: Despite growing interest in quantifying and correcting vitamin D inadequacy in basketball players, a critical synthesis of these data is yet to be performed to overcome the low generalizability of findings from individual studies. Objective: To provide a comprehensive analysis of data in basketball pertaining to (1) the prevalence of vitamin D inadequacy; (2) the effects of vitamin D supplementation on 25-hydroxyvitamin D [25(OH)D] concentration (and its association with body composition), bone health, and performance; and (3) crucial aspects that warrant further investigation. Data Sources: PubMed, MEDLINE, ERIC, Google Scholar, SCIndex, and ScienceDirect databases were searched. Study Selection: After screening, 15 studies were included in the systematic review and meta-analysis. Study Design: Systematic review and meta-analysis. Level of Evidence: Level 3. Data Extraction: The prevalence of vitamin D inadequacy, serum 25(OH)D, body composition, stress fractures, and physical performance were extracted. Results: The pooled prevalence of vitamin D inadequacy for 527 basketball players in 14 studies was 77% (P < 0.001; 95% CI, 0.70-0.84). Supplementation with 4000 IU/d and 4000 IU/wk (absolute mean difference [AMD]: 25.39 nmol/L; P < 0.001; 95% CI, 13.44-37.33), as well as 10,000 IU/d (AMD: 100.01; P < 0.001; 95% CI, 70.39-129.63) vitamin D restored 25(OH)D to normal concentrations. Body composition data revealed inverse correlations between changes in serum 25(OH)D (from pre- to postsupplementation) and body fat (r = −0.80; very large). Data concerning positive impacts of vitamin D supplementation on bone health and physical performance remain sparse. Conclusion: The high proportion of vitamin D inadequacy underscores the need to screen for serum 25(OH)D in basketball players. Although supplementation restored vitamin D sufficiency, the beneficial effects on bone health and physical performance remain sparse. Adiposity can modulate 25(OH)D response to supplementation.