Calcium metabolism in pregnancy and lactation.

Homeostatic adaptation to maternal calcium metabolism is a prerequisite for optimal delivery of sufficient calcium to the fetus and neonate during pregnancy and lactation, respectively. This article outlines the major adaptations known to occur and the physiological regulators likely to be principally involved. Importantly, different adaptive responses are used in pregnancy and lactation. The rarity of calcium disorders in pregnancy underscores the successful implementation of these adaptations in most women. For those few women with either pre-existing or pregnancy-acquired disorders of calcium metabolism, a knowledge of normal physiology is essential to understand the implications for managing these disorders in pregnant women.