Calcium

Calcium is the most abundant mineral in the body. It is found in some foods and is
manufactured as a dietary supplement. Calcium is required for muscle contraction, blood vessel
expansion and contraction, secretion of hormones and enzymes, and transmitting impulses
throughout the nervous system.
Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and
Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus,
Magnesium, Vitamin D and Fluoride. Washington, DC: National Academy Press, 1997.
The body strives to maintain constant concentrations of calcium in blood, muscle, and
intercellular fluids, though less than <1% of total body calcium is needed to support these
functions. The remaining 99% of the body's calcium supply is stored in the bones and teeth
where it supports their structure.