RESUMO
Little is known about the zinc content of breast milk in developing countries. Zinc content in breast milk was analyzed in 34 mothers of low socio-economic status; 17 were primiparae and 17 multiparae. Women in their 6th to 36th week of lactation provided 3 samples of breast milk at different times within a single day. The mean zinc concentration in breast milk (micrograms/ml) was 1.89 +/- 0.64 with a range from 0.17 to 4.38 micrograms/ ml. Zinc content in the morning, midday and evening samples were 2.1 +/- 0.84, 1.74 +/- 0.53, 1.84 +/- 0.69 respectively. There was significant variation between morning and midday samples (p = 0.038). Maternal age, parity, nutritional status or age of the child did not affect the zinc content of milk in the population studied.