Calcium D is a trade name for calcium carbonate D3 tablets, which are commonly used in calcium supplementation therapy. Pregnant women can take Calcium D orally to promote the concentration of calcium ions in their bodies, and middle-aged and elderly patients can take this drug orally for anti-osteoporosis treatment. This drug is rich in calcium carbonate and rich in vitamin D3, because if calcium ions want to be absorbed by the body, it needs vitamin D3 to carry out the catalytic effect, and this drug is a synthetic drug that combines two drugs together. Therefore, it is clinically accepted by most doctors and patients because it avoids the side effects of taking two drugs at the same time or the problem of taking them at the same time. In addition, this drug is rich in calcium and vitamin D3, and one tablet a day can be taken orally for calcium supplementation, and two tablets a day can be taken for 1200mg of calcium supplementation if necessary or in severe cases.