Calcium is the most abundant mineral in the human body.  It makes up two percent of the adult body weight.  Ninety-nine percent of the  body calcium is found in the bones and teeth.  The other one percent if found in the blood, extracellular fluids, and within cells where it is a cofactor and activator for numerous enzymes.  In addition to being a major structural mineral, calcium is also required for the release of energy from ATP for muscular contraction, and blood clotting.  Calcium effects the release of neurotransmitters at synaptic junctions.  It also mediates the synthesis, secretion, and metabolic effects of hormones and enzymes, regulates heart beat, muscle tone, and muscle receptivity to nerve stimulation.  Recently, calcium has been shown  to promote weight loss, especially in terms of fat loss, and prevent cancer.  However, these findings are not yet universally accepted.

There are no less than 147 deficiency diseases that can be attributed to calcium deficiencies or imbalances.  The most recent clinical research clearly points out that the entire scope of American diets are critically  deficient in calcium.  The only practical way to get enough calcium is through supplementation.  Calcium deficiencies can result from lack of vitamin D.  The decrease in stomach acid as we age results in lower absorption of calcium, since calcium can only be absorbed in an acid enviroment.  High fiber diets and fiber supplements will decrease calcium absorption as well as certain pharmaceutical drugs; thyroid and anti-seizure medications, diuretics, and iron preparations.  These should be taken at different times of the day.  Excessive sugar and caffeine from coffee, tea, colas, etc. will leach calcium from the bones. The amino acid lysine and vitamin D are needed for calcium absorption.