RESUMO
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.
Assuntos
Animais , Feminino , Ratos , Cálcio da Dieta/administração & dosagem , Fêmur/metabolismo , Lactação , Gravidez , Zinco/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Dieta , Fêmur/química , Estudos Longitudinais , Lactação/metabolismo , Ratos Wistar , Zinco/sangueRESUMO
The purpose of this study was to investigate the impact of low fat diets in children aged 2 to 5. Eighty two children (40 females and 42 males) attending a school cafeteria (Province of Buenos Aires, Argentina), in a cross sectional study, were evaluated. Body weight (W), height (H) and body composition (BC) by bioimpedance were recorded. The anthropometric raw data were processed as Z-score of the weight-for-age (WEZ) and of the height-for-age (HAZ). Serum insulin-like growth factor 1 (IGF-1) and Zinc/haemoglobin ratio (Zn/Hb) were also measured. Results showed that 73.2 per cent of children were adequate (A) according WEZ, 13.4 per cent were lean (L) and 13.4 per cent overweight (O). 8.5 per cent presented simultaneously impairment in WEZ and HAZ. Body fat percentage and energy metabolism were higher in O than in L and A (p < 0.05). Serum IGF-1's children--aged 4 to 5 years--with HAZ deficit were low than adequate HAZ ones. No statistical differences in Zn/Hb ratio between A, L and O were found. This cross sectional study suggests metabolic disorders in young children attending school cafeterias. These conclusions will allow to design balanced diets in order to optimize the resources, promote optimal growth and development and prevent adult diseases through dietary practices in childhood.