Calcium is a metal that is very abundant in the Earth’s crust; it is an essential element for many living beings, including humans. It is involved in metabolism, the acid-base balance, cellular exchanges throughout the body, and muscle contraction. The level of calcium in blood and its storage are very finely regulated by a complex hormonal system. Calcium is also a major component of bones and teeth and contributes to their hardness and relative rigidity.
Calcium is supplied through a varied and balanced diet but if needed, the body can take some out of the bones, the main storage site for calcium, to maintain or restore normal blood levels. To support good bone health, intakes of calcium, whether from the diet or from supplements in bioavailable form, should be sufficient to offset daily losses.