Oral calcium tablets need to be targeted and should not be used blindly. If calcium is supplemented blindly, it may cause adverse consequences. If the body is deficient in calcium and there are obvious clinical symptoms or obvious abnormalities after trace element examination, oral calcium tablets can be taken. Appropriate oral calcium tablets can effectively prevent calcium loss, especially for some middle-aged and elderly people. Calcium supplementation can reduce the probability of osteoporosis and also alleviate their clinical symptoms, such as frequent weak legs, frequent feeling of impotence and weakness in both lower limbs, calf cramps, and also improve heart function and significantly improve clinical symptoms such as arrhythmia and palpitations. For some developing adolescents, proper calcium supplementation can promote physical development and avoid transient micronutrient deficiency caused by rapid development during growth and development. For infants and young children, it can effectively prevent rickets and improve night sweats, irritability, occipital baldness and irritability caused by calcium deficiency. The prerequisite for calcium supplementation is that the body must be confirmed to be deficient in calcium after the relevant examination before targeted supplementation.