Hormonal calcium regulation and calcium setpoint in offspring of bitches with different calcium intakes during pregnancy

High maternal calcium (Ca) intake may lead to alterations in development and differentiation of fetal tissues and may result in altered 'programming' of Ca homeostasis, with eventual effects on Ca handling and skeletal development in the offspring during later life. In bitches fed a diet with a Ca intake three times above recommendations (3.27 g/100 g vs 1.14 g/100 g dry matter) during the second half of pregnancy, the plasma concentration of 1,25 dihydroxy cholecalciferol (1,25 (OH)(2) vit D) appeared to decrease, while plasma Ca, phosphorus (P), parathyroid hormone (PTH) and calcitonin (CT) concentrations remained unchanged. High maternal Ca intake did not result in altered basal or stimulated plasma concentrations of Ca, P, PTH, CT and 1,25 (OH)(2) vit D in the offspring (n=7) when compared with pups from bitches fed a normal Ca diet during the entire pregnancy (controls, n=7). The Ca setpoint for PTH secretion (S-Ca(for PTH)) was therefore not different from controls. From this pilot study it may be concluded that excessive Ca intake during late pregnancy in the bitch has no deleterious effects on hormonal Ca homeostasis in the offspring.