Calcium metabolism without anguish. Understanding the body's homeostatic 'black box'

Advances in the understanding of calcium metabolism and in the ability of measure resultant changes in the levels of parathyroid hormone (PTH), vitamin D metabolites, and nephrogenous cAMP have made the diagnosis of most disorders of calcium metabolism a straight forward proposition. When disorders of calcium homeostasis occur, consideration of each of the three 'interface' organ systems and of the roles played by PTH and vitamin D metabolites at each of these interfaces will result in rapid and accurate diagnosis, as well as in a deeper understanding of the causal pathophysiology.