Studies of nutrient composition of transitional human milk and estimated intake of nutrients by breast-fed infants in Korean mothers

Purpose: This study was conducted to examine the concentration of nutrients in transitional breast milk from Korean lactating mothers and to evaluate daily intakes of their infants based on the Dietary Reference Intakes for Koreans 2010 (KDRIs 2010). Methods: Breast milk samples were collected at 5~15 days postpartum from 100 healthy lactating Korean mothers. Macro- and micro-nutrients, and immunoglobulin (Igs) concentrations in breast milk were analyzed. Results: The mean energy, protein, fat, and carbohydrate concentrations in breast milk were 59.99 ± 8.01 kcal/dL, 1.47 ± 0.27 g/dL, 2.88 ± 0.89 g/dL, and 6.72 ± 0.22 g/dL. The mean linoleic acid (LA), a-linolenic acid (ALA), arachidonic acid (AA), and docosahexaenoic acid (DHA) concentrations were 181.44 ± 96.41 mg/dL, 28.15 ± 8.89 mg/dL, 5.67 ± 1.86 mg/dL, and 5.74 ± 2.57 mg/dL. The mean vitamin A, vitamin D, vitamin E, vitamin B1, vitamin B2, vitamin B12, and folate concentrations were 2.75 ± 1.75 μg/dL, 2.31 ± 1.12 ng/dL, 0.74 ± 1.54 mg/dL, 3.02 ± 1.84 mg/dL, 7.51 ± 20.96 μg/dL, 61.78 ± 26.78 μg/dL, 63.71 ± 27.19 ng/dL, and 0.52 ± 0.26 μg/dL. The mean concentrations of calcium, iron, potassium, sodium, zinc, and copper were 20.71 ± 3.34 mg/dL, 0.59 ± 0.86 mg/dL, 66.71 ± 10.35 mg/dL, 27.72 ± 10.16 mg/dL, 0.44 ± 0.41 mg/dL, and 70.48 ± 30.41 μg/dL. The mean IgA and total IgE concentrations were 61.85 ± 31.97 mg/dL and 235.00 ± 93.00 IU/dL. The estimated daily intakes of infants for protein, vitamin D, vitamin E, vitamin B₂, vitamin B 12 , iron, potassium, sodium, zinc, and copper were sufficient compared to KDRIs 2010 adjusted by transitory milk intakes. The estimated infants" intakes of energy, fat, carbohydrate, vitamin A, vitamin C, vitamin B₁, folate, and calcium did not meet KDRIs 2010 adjusted by transitory milk intakes. Conclusion: In general most estimated nutrient intakes of Korean breast-fed infants in transitory breast milk were sufficient, however some nutrient intakes were not sufficient based on KDRIs 2010. These results warrant conduct of future studies for investigation of important dietary factors associated with nutrients in breast milk to improve the quality of breast milk, which may contribute to understanding nutrition in early life and promoting growth and development of breast-fed infants.