Metabolismo del calcio

Abstract

Calcium is essential for intracellular functions as well as for normal growth and development. Body calcium is mainly regulated by digestive tract. Calcium body content is the largest among the electrolytes. Over 90% of the body calcium is stored in the bones and teeth as hydroxiapatite crystals. Ninety nine per cent of total body calcium is not available for immediate homeostasis and only 1% of it is in plasma or extravascular fluid. Calcium ion in plasma or cytosol plays a major role in cellular activity. Many vital functions are mediated by cellular and serum calcium and skeletal functions and dental integrity are affected during conditions of relative calcium deficiency. Chronic calcium deficiencies may present clinically as rickets or osteomalacia during infancy and early childhood and as osteoporosis in the adult. Although calcium and phosphorus bone deposits increase during adolescence, calcium and phosphorus reserves are slowly depleted during adulthood (specially in women) causing osteoporosis.