Association of vitamin D levels with bone density in patients with osteoporosis

Background Osteoporosis is a prevalent skeletal disorder characterized by reduced bone mass and deterioration of bone microarchitecture, leading to an increased risk of fractures. Given the growing recognition of the association between vitamin D (VitD) and bone health, there is a pressing need to conduct studies focusing on the level of VitD and its correlation with bone mineral density (BMD) in osteoporosis patients. This study aims to address this critical knowledge gap by exploring the association between VitD levels and bone mineral density in osteoporosis patients from an Iranian population. Methods We recruited 500 subjects with osteoporosis and 500 non-osteoporosis cases. The BMD of the cases was measured in the hip, femur neck, and L1-L4 spine using the Stratos device via DXA method. VitD level was measured in the serum of study participants using ELISA. Results VitD level was significantly lower in the osteoporosis cases (31.15 ± 9.44 nmol/L) compared to the non-osteoporosis subjects (41.65 ± 10.25 nmol/L). It was significantly higher in the male subjects compared to female patients in the osteoporosis group ( P  = 0.048). In both osteoporosis ( P  = 0.008) and non-osteoporosis ( P  = 0.001) subjects, the level of VitD was significantly lower in the subjects with a history of bone fracture compared to those without a history of bone fracture. The VitD level had significantly positive correlation with the BMD of hip ( r  = 0.44, P  = 0.001), spine, and femur. Conclusions VitD deficiency in the osteoporosis patients is associated with BMD and bone fractures.