Hamed Mohammadi - Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Karim Parastouei - Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Hosein Rostami - Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Maryam Miraghajani - Nottingham Digestive Disease Centre and Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
Masoumeh Rafiee - Student Research Committee, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
Abed Ghavami - Student Research Committee, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
Anastasia Viktoria Lazaridi - The Early Life Research Unit, Division of Child Health, Obstetrics and Gynaecology, School of Medicine, University of Nottingham, Nottingham, UK

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 ۲۰۲۰, 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.

Spinal cord injury, Vitamin D, Systematic review.