IJSR International Journal of Scientific Research 2277 - 8179 Indian Society for Health and Advanced Research ijsr-10-9-36660 Original Research Paper A Cross-sectional Study on the prevalence of vitamin D deficiency in children with chronic musculoskeletal pain and its comparison with respect to joint hypermobility at Patna Medical College, Bihar Kumar Dr. C B Kumar Dr. September 2021 10 9 01 02