or skeletal calcium stored in bones, is distributed among a relatively non-exchangeable, which is stable and quickly interchangeable space, which is involved in metabolic activities. Josyann Abisaab The interchangeable component can be considered a reserve to be accumulated when the diet provides adequate intake of calcium. It is stored mainly at the ends of long bones and is mobilized to meet increased needs for growth, pregnancy and lactation. Without such reservation, the calcium must be subtracted from the same bone stock, if inadequate calcium intake is prolonged resulting in poor bone structure. Calcium is present in bones in the form of hydroxyapatite, a crystalline structure that consists of calcium phosphate which is arranged around an organic matrix of collagenous protein to provide strength and rigidity. Many other ions are present, such as fluorine, magnesium, zinc and sodium.The mineral ions diffuse into the extracellular fluid bathing the crystals and allowing the deposition of new minerals. The same types of crystals are present in enamel and dentin of the teeth, there is little exchange of minerals and calcium is not readily available for periods of deficiency. In the process of bone formation and remodeling involved ostecl sticas cells (cells of bone resorption) and osteoblasts (cells forming), controlled in turn by several systemic hormones (parathyroid hormone and calcitonin), the nutritional status of vitamin D and regulatory factors growth (1).