Calcium is one of the most essential minerals required in the body since it is involved in so many body functions. It is needed for maintaining healthy bones, teeth, nerve function, muscle contraction and the body's acid-alkaline balance. Calcium, like many minerals, is often not absorbed well and so many people take a supplement to ensure sufficient intake. It is dependent on vitamin D, phosphorus and vitamins A and C for ideal absorption.
Calcium is available in many different forms; refined calcium carbonate and chelated calcium, such as calcium citrate and calcium gluconate, are more easily assimilated by the body. People with insufficient stomach acid, particulary post-menopausal women, should supplement with the chelated form. Regular exercise also helps facilitate calcium absorption.