Calcium is the main structural mineral in the body. About 99% of the body´s 3 pounds of calcium is in the skeleton and teeth and is accountable for their resistance and strength. Calcium in the bones and teeth is not always located there, this is since the bones and teeth also serve as reservoir for calcium. There is an almost continual exchange of calcium between the bones and the body fluids and soft tissues, where the rest of the calcium is located. If calcium consumption does not make up for what is lost through excretion, what is taken from the bones will not be substituted.
The other 1% of the body´s calcium outside the skeleton is also very important. It is vital for the strength of the intracellular membranes and for many important enzyme responses involved in the coagulation of the blood and other processes; normal muscular contraction and relaxation, including the rhythm of the heart depends on calcium.
For obvious reasons, calcium is vitally significant for growth and development.
Besides its properties on bone mineralization and nerve and muscle irritability, calcium deficit can also disturb blood and tissue levels of two poisonous metals: lead and cadmium. When dietary calcium is low, the body maintains more lead. This has been established in several experiments with both humans and animals: low dietary calcium origins high blood and tissue levels of lead. Cadmium, another toxic chemical, is also reserved by the body in higher concentrations when calcium is low.