MINERAL INTERACTIONS IN RATS FED AIN-76A DIETS WITH EXCESS CALCIUM

The effects of moderate increases in dietary calcium on maternal and f oetal mineral interactions were studied in Charles River CD/VAF Plus r ats. Female rats were given 0.50, 0.75, 1.00 or 1.25% dietary calcium as calcium carbonate in AIN-76A diets for 6 wk before mating, during m ating and for 20 days of gestation. Inductively coupled argon plasma-a tomic emission spectrometry was used to determine mineral levels in th e tissues of non-pregnant rats after 42 days on the diets, in the tiss ues of pregnant rats on day 20 of gestation and in the whole body of d ay-20 foetuses. The femurs of the non-pregnant and pregnant rats had a dose-related linear increase in calcium content. In livers of the non -pregnant rats, dose-related linear increases in the phosphorus, zinc and magnesium content were observed, but there was a dose-related decr ease in the iron content. There were dose-related linear decreases in the iron and copper contents of the kidneys from the non-pregnant rats . In pregnant rats dose-related linear decreases were observed in the iron content of the liver and in the zinc, iron and magnesium contents of the kidney. The foetuses from rats given a moderate increase in di etary calcium had dose-related decreases in the whole-body contents of phosphorus, iron, copper and magnesium.