chapter  7
8 Pages

Renal Regulation of Calcium and Phosphate Ions

An understanding of normal mineral metabolism is essential to understand the classical hormonal endocrine feedback system, which maintains optimal concentrations of calcium and phosphorus in the extracellular —uids while simultaneously serving to regulate external calcium and phosphate balances to facilitate skeletal health. These classical control systems interrelate with each other by means of negative feedback to maintain optimal extracellular concentrations of calcium and inorganic phosphate. Bone not only provides an abundant endogenous source of these minerals to supply extracellular —uids, but it also functions to buffer excess supplies of these minerals entering extracellular —uids from external dietary sources. These same regulatory systems also help maintain skeletal integrity during adult life as well as facilitate skeletal growth during childhood and adolescence. Appropriate mineral balance is maintained across wide ranges of dietary calcium and phosphorus intakes.