Summary Breast milk is considered to be the best nutrient source for infants. However, nutritional compositions of breast milk in developing countries, especially among malnourished women, have not been fully investigated. This study aimed to assess nutritional status and nutrient composition of breast milk in lactating mothers in rural Vietnam. Sixty breastfeeding mothers at 6 to 12 mo postpartum, free from any medical disorder and/or medication, and not pregnant were randomly selected in Yen The, Bac Giang, Vietnam. Their nutritional status, breast milk concentration and dietary intakes were assessed. Among the study participants, anemia (39.0%) and low serum zinc concentration (55.4%) were frequently observed. Dietary assessment revealed lower intakes of iron (10.2 Ϯ 2.5 mg/d) and zinc (10.4 Ϯ 2.2 mg/d) than estimated requirements. The breast milk concentration of iron, zinc and copper was 0.43 Ϯ 0.15 mg/L, 0.56 (0.37, 0.82) mg/L and 0.19 Ϯ 0.05 mg/L, respectively. The breast milk concentration of iron, zinc and copper was not correlated to the serum concentration or dietary intakes. In conclusion, we uncovered a high prevalence of anemia and zinc deficiency in lactating mothers in rural Vietnam. The findings demonstrate a low breast milk zinc concentration among the participants, but need further investigation.

Japanese breast-fed infants were more likely to be anemic at 6 months, while formula-fed infants were likely to have low serum lipid levels. Iron-fortified infant foods may be useful to prevent anemia in breast-fed infants. Fat quality of infant formulas should be improved to enhance lipid status of formula-fed infants.