Interrelations of calcium-regulating hormones during normal pregnancy

Abstract

Profound changes in calcium metabolism occur during pregnancy. The mother has to make available extra calcium for fetal requirements while ensuring that her plasma and bone calcium concentrations are satisfactorily maintained. In a cross-sectional study plasma concentrations of the major calcium-regulating hormones- namely, calcitonin, parathyroid hormone, 25- hydroxyvitamin D (25-OHD), and 1,25-dihydroxyvitamin D (1,25-(OH)2D)-were measured to establish their interrelations during normal pregnancy. The major changes observed were increases in the circulating concentrations of 1,25-(OH)2D and calcitonin. Concentrations of parathyroid hormone and 25-OHD remained within the normal range. © 1981, British Medical Journal Publishing Group. All rights reserved.