Calcium deficiency will show symptoms such as bone diseases, convulsions, sensory abnormalities and muscle weakness. 1. Skeletal diseases: children can cause rickets, which is manifested as delayed closure of fontanel, square head, chicken chest, O or X-shaped legs, etc. Adults can show bone softening, osteoporosis and fibrositis. 2. Convulsions: When hypocalcemia is severe, it can lead to twitching of hands and feet, pharyngeal spasms, twitching of face and back muscles, spasticity of legs and epileptic seizures. 3. Sensory abnormalities: When blood calcium is low, numbness of lips, tongue, hands and feet with tingling sensation can occur. 4. Muscle weakness: For example, patients may have recent generalized weakness without obvious triggers, and persistent muscle fatigue after work or exercise. It is recommended that patients with calcium deficiency go to the hospital in a timely manner to determine the treatment plan under the guidance of the doctor, to avoid blindly using their own medication.