Vitamin D Supplementation in Adults with Spinal Cord Injury: A Systematic Review

The current systematic review was conducted to investigate the effects of vitamin D supplementation on vitamin D levels, bone health, and physical performance indices in adults with spinal cord injury (SCI). Methods: The PubMed, Scopus, Web of Science, and Embase databases were searched for studies published up to June 2020, with no language limits. To determine the risk of bias, the Academy of Nutrition and Dietetics Quality criteria checklist was used. Results: Eight studies that met all of the inclusion criteria were identified. All of the eligible studies had a high level of heterogeneity regarding outcome measures, study design, and the dose of vitamin D. The majority of the trials showed beneficial effects of vitamin D supplementation on serum vitamin D levels and other outcome measures in patients with SCI. Three randomized controlled trials revealed a low risk of bias, whilst other studies were rated as the  either neutral or negative risk of bias. Conclusion: This review suggests that vitamin D supplementation could improve vitamin D levels, bone health, and physical performance indices in individuals with SCI. However, due to the high level of heterogeneity, the results should be interpreted with caution. Further studies on this population should be performed to have sufficient power and a robust design to give definitive conclusions.