Comparison of Vitamin D Levels in Children with Musculoskeletal Pain with and without Hypermobility of Joints

Background Vitamin D supplementation has been suggested as a part of an interdisciplinary approach for the management of chronic musculoskeletal pain in children and adolescents. This study aimed to compare vitamin D serum levels in Iranian children with chronic musculoskeletal pain with and without hypermobility. Materials and Methods: This cross-sectional study was performed on otherwise healthy children aged 16 years or younger with chronic musculoskeletal pain, who were admitted to the rheumatology clinic of Bahrami Children Hospital, Tehran, Iran, from January 2018 to January 2019. Chronic musculoskeletal pain was defined as recurrent episodes of musculoskeletal pain within the past month to the past week. The subjects were categorized into two groups, with or without hypermobility. Hypermobility was diagnosed using Modified Criteria of Carter and Wilkinson. Serum 25-hydroxy vitamin D (25-(OH)D) level and baseline characteristics were compared, and 25-(OH)D <30 ng/mL was considered deficiency. Results: A total of 72 children (41 girls and 31 boys, with the mean age of 7.36 ± 2.42 years) were included. Most participants (73.6%) were 3 to 7 years old. Sixty-four patients (88.8%) were diagnosed with vitamin D deficiency (25(OH)D <30 ng/mL). Children without joint hypermobility had a lower vitamin D level and a higher prevalence of vitamin D deficiency compared to those with hypermobility. However, the difference was not statistically significant. Conclusion Our study results suggested a high prevalence of vitamin D deficiency among children and adolescents with chronic musculoskeletal pain, but the difference in vitamin D deficiency between children with and without hypermobility was not statistically significant.