Vitamin D in Basketball Players: Current Evidence and Future Directions.

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% ( < 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; < 0.001; 95% CI, 13.44-37.33), as well as 10,000 IU/d (AMD: 100.01; < 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 ( = -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.