Changes in ionised Mg2+ and Ca2+ in maternal serum during weaning in goats.

Abstract

Ionised levels of serum magnesium (Mg2+) and calcium (Ca2+) were measured in HEPES-buffered serum from lactating goats before and during weaning. During this period, there was a significant rise in serum Ca2+, and a concomitant fall in Mg2+. These opposing changes can be explained by the known enhanced absorption of Ca relative to Mg by the gut during lactation coupled with a Ca-induced suppression of PTH-driven renal Ca and Mg reabsorption. A rise in the serum Ca2+/Mg2+ ratio during weaning suggests that this is a period of potential cardiovascular risk for the mother, and merits closer study