Relationship between breast milk content and intake of zinc, copper and iron of Nigerian women

Abstract

Zinc, copper and iron intakes of 226 lactating Nigerian women eating self-selected diets was assessed via a cumulative 3-day dietary recall method -the trace element composition of subsamples of the diets having been analysed by atomic absorption spectrophotometry. Breast milk collected from the subjects was also analysed for zinc, copper and iron content. Mean (+S.E.) daily zinc, copper and iron intakes during the first weeks of lactation were 8.50 ± O.11 mg, 1.70 ± 0.03 mg and 29.40 + 0.44 mg, respectively. Except for iron, the values were much lower than RDA. Mean daily intake tended to decrease with increase in lactation period. Colostrum zinc, copper and iron concentrations (µg/dl) of 583.70 ± 13.27, 54.50 + 2.95 and 52.40 ± 2.60 µg, respectively, were significantly higher than the values obtained for the respective elements in mature milk. Variations in dietary zinc and iron intake levels were observed to influence breast milk zinc and iron concentrations. Neither maternal age nor parity had any influence on milk trace elements levels.

Concentrations of iron, copper and zinc in human milk and powdered infant formula

“…Significant differences (P < 0.05) among the mean concentrations of the metals studied for the 11 mothers considered were observed, which is in agreement with other authors (Arnaud et al, 1991). In contrast, other authors (Dang et al, 1984;Krebs et al, 1984;Krebs et al, 1985b;Mbofung & Atinmo, 1986) have found Zn levels significantly higher in milk of supplemented women with regard to unsupplemented. In this sense, a wide number of authors (Feeley et al, 1983;Fomon, 1995;Kirksey et al, 1979;Krebs et al, 1985a;Lönnerdal, 1986;Mbofung & Atinmo, 1986;Moore et al, 1984;Moser & Reynolds, 1983;Vaughan et al, 1979;Vuori et al, 1980) have described that Fe, Cu and Zn concentrations of human milk seem to be unrelated to the nutritional Fe status of wellnourished lactating mothers, and is little influenced by metal supplements of their diet.…”

“…Approximate daily intakes of children fed with human milk and powdered infant formula are also included in this table. In this sense, a wide number of authors (Feeley et al, 1983;Fomon, 1995;Kirksey et al, 1979;Krebs et al, 1985a;Lönnerdal, 1986;Mbofung & Atinmo, 1986;Moore et al, 1984;Moser & Reynolds, 1983;Vaughan et al, 1979;Vuori et al, 1980) have described that Fe, Cu and Zn concentrations of human milk seem to be unrelated to the nutritional Fe status of wellnourished lactating mothers, and is little influenced by metal supplements of their diet. These great individual differences in the excretion of the metals studied through human milk cannot be explained by an effect of dietary intake.…”