The main role of calcium tablets is to replenish the calcium needed by the body, which can prevent osteoporosis caused by calcium deficiency in middle-aged and elderly people, and also prevent muscle spasm of gastrocnemius muscle caused by calcium deficiency. For adolescents, calcium tablets should be supplemented to maintain the calcium needed for growth and development of the body. Appropriate oral calcium tablets for infants and children can prevent rickets, which is for patients with calcium deficiency. Calcium, a trace element, is also widely involved in enzyme activity, in nerve and muscle activity, as well as in the release of neurotransmitters, and is closely related to hormone secretion, so calcium tablets can improve muscle spasms caused by calcium deficiency. Muscle contraction and blood clotting, including cell adhesion, are also closely related to calcium. Calcium can also regulate heart rhythm, reduce cardiovascular permeability and maintain acid-base balance. Calcium deficiency can cause arrhythmia, and calcium tablets can effectively improve the arrhythmia caused by calcium deficiency, and also enhance the symptoms of immunity and cold caused by calcium deficiency.