Calcium is a mineral found in many foods. The body needs calcium to maintain strong bones and to carry out many important functions. Almost all calcium is stored in bones and teeth, where it supports their structure and hardness.
The body also needs calcium for muscles to move and for nerves to carry messages between the brain and every body part. In addition, calcium is used to help blood vessels move blood throughout the body and to help release hormones and enzymes that affect almost every function in the human body.
Calcium is used for treatment and prevention of hypocalcemia, osteoporosis, rickets, and latent tetany. It is also used orally for hypoparathyroidism, osteomalacia, leg cramps and reducing the risk of colorectal cancer. Calcium is also used orally for diarrhea and rectal epithelial hyperproliferation following intestinal bypass, hypertension, elevated levels of low-density lipoprotein (LDL), Lyme disease, elevated fluoride levels in children, and elevated lead levels. Calcium is also used for metformin-related vitamin B12 deficiency.