CRP and rickets: Vitamin D is a hormone that regulates calcium and bone metabolism and is important in the inflammatory and immune response of the body. Inflammatory parameters such as interleukin 6, tumor necrosis factor, and C-reactive protein (CRP) are high in patients with low back pain, which may be related to D hypovitaminosis, and patients with CRP > 3 are more likely to have low back pain [7-9].