Dietary Intake and Milk Micronutrient Levels in Lactating Women with Full and Partial Breastfeeding

Abstract

Background: Micronutrient intake and status in lactating women may impact micronutrient levels in milk. Objectives: This study aimed to determine the micronutrient intake and status in lactating women, and their association with micronutrient levels in human milk. Methods: Lactating women were enrolled at 4–6 months postpartum. A 24h food recall was examined and nutrient intakes were analyzed using INMUCAL software. Human milk samples were collected to analyze calcium, copper, iron, and zinc levels. Plasma zinc and serum ferritin levels were determined. Results: Thirty-four women participated; 19 were classified as full breastfeeding and 15 as partial breastfeeding. Mean levels of calcium, copper, iron, and zinc in human milk were 243, 0.2, 0.2, and 1.56 mg/L, respectively. The prevalence of zinc deficiency (plasma zinc < 10.7 µmol/L) was 11.8%. No lactating women had iron deficiency. Nutrient intakes were lower than the recommended amounts in 38%–70% of participants, and were not correlated with corresponding nutrient levels in human milk. Multiple linear regression showed significant association between zinc levels in human milk and plasma for lactating women with full breastfeeding (β = 0.034, 95% confidence interval [0.003, 0.067], p = 0.040). Conclusions: Lactating women were at risk of micronutrient deficiency. There was an association between zinc levels in human milk and plasma of lactating women with full breastfeeding. As the nutritional status of lactating women influences the quality of human milk, we should encourage good nutrient intake for lactating women.