Efecto del nivel de calcio de la dieta consumida durante gestación y lactancia sobre el zinc en sangre y hueso, en ratas / Effect of dietary calcium during pregnancy and lactation on zinc levels in blood and bone, in rats

ABSTRACT

The effect of dietary calcium (Ca) level on maternal zinc (Zn) nutritional status was studied. Female Wistar rats, weighing 250-350 g, were fed during pregnancy and lactation with an experimental diet containing/100 g different levels of calcium 0.2 g (low calcium LCa), 0.6 g (normal calcium NCa) or 0.9 (high calcium HCa). Maternal blood samples were drawn from the tail at delivery and at the end of lactation. Laboratory determinations were Zn in whole blood (WB) at delivery and weaning; Zn (ZnF) and Ca (CaF) in the ashed femur at weaning. The results (mean +/- SEM) were ZnWB (microgram/ml) at delivery and weaning LCa 8.73 +/- 1.05; 12.8 +/- 2.02; NCa 3.49 +/- 0.19; 3.73 +/- 0.37; HCa 3.21 +/- 0.19; 3.85 +/- 0.27. CaF (mg/100 mg) LCa 19.2 +/- 0.8; NCa 21.4 +/- 0.6; HCa 20.4 +/- 1.1. ZnF (microgram/100 mg) LCa 30.2 +/- 0.9; NCa 24.1 +/- 0.3; HCa 24.1 +/- 0.9. ZnWB was significantly higher in LCa (p < 0.0001) regarding NCa and Hca. ZnF showed an increase and CaF a decrease in LCa regarding NCa and HCa (p < 0.0001). There were no significant differences in ZnWB, ZnF and CaF between NCa and HCa These results show that there was no detrimental effect when dietary Ca content was increased by 50 per cent above the normal requirements of the rat.; low dietary Ca during pregnancy and lactation produced an increase of Zn utilization, reflected in maternal blood Zn and in ZnF content.