Femoral head necrosis disease is not related to calcium deficiency. The most common clinical causes of femoral head necrosis are previous trauma to the hip joint, such as dislocation, fracture of the femoral neck and fracture of the femoral head, prolonged alcohol consumption and heavy use of hormones, which are by far the most common causes of femoral head necrosis. There is an obvious lack of calcium that can lead to osteoporosis in the body, but osteoporosis is not osteonecrosis of the femoral head. Femoral head necrosis is caused by the death and apoptosis of bone cells inside, active osteoclasts, and impaired blood circulation in the small blood vessels in the bones, none of which are related to calcium deficiency. In the case of femoral head necrosis, it is necessary to look for specific causes, such as prolonged alcohol consumption, hormone use or previous traumatic injuries.