Calcium, New RDA* 800 mg
The human body requires more calcium than any other mineral. At least 99% of the calcium is found in the bones and teeth, giving them strength and rigidity. The remaining 1%, which is in the blood, muscles, and nerves, plays an important role in regulating physiological functions.
Calcium is a white, malleable, metallic element. In the body it is found in various combinations such as calcium carbonate, calcium phosphate, calcium fluoride, and calcium sulphate. Large quantities of fat, oxalic acid, and phytic acid in the food can prevent proper calcium absorption.
Calcium does not exist freely in nature, but occurs abundantly as limestone (CaCO3), gypsum (CaSO4.2H2O), and fluorite (CaF2). Many calcium compounds (e.g. fluorspar and calcium carbonate) are almost insoluble in water, but there are exceptions (e.g. calcium chloride and calcium nitrate).
*Sourced from EFSA WEBSITE