Calcium tablets are called Calcium D tablets, which is a kind of therapeutic drug mainly used for calcium supplementation produced by Wyeth in the United States. The main ingredients of Calcium D tablets are calcium and vitamin D to promote the absorption of calcium, so it is strictly speaking a kind of compound drug. It is mainly used clinically for the treatment of osteoporosis, promoting fracture healing and rickets in children, as well as calcium supplementation for women with calcium deficiency during lactation or pregnancy. For patients with severe calcium deficiency, a combination of Calcium D tablets and more powerful drugs that promote calcium absorption, such as osteopontin, is often required.