[Chemical composition of human milk. Influence of the nutritional status of the nursing mother].

The chemical composition of human milk obtained from 16 underweight women and 25 controls collected at four, eight and 12 weeks of lactation, was determined in order to assess the effect of maternal nutrition upon milk quality. No meaningful differences were observed for protein, lactose, energy, calcium, iron and copper contents. The values obtained are comparable to those reported in the literature from developed countries. As to Zn content, both groups exhibited decreased values with time, with significant higher values for the controls at the 12th week of observation. Magnesium showed exactly the opposite behavior. On the basis of the present study, it is concluded that maternal nutrition does not condition important changes in the chemical composition of human milk. The authors propose the application of comparable methodologic and analytical criteria, in order to achieve a more complete understanding of the relationships between maternal nutrition and lactation.