Macronutrient, mineral and trace element composition of breast milk from Japanese women

Large differences were found to exist among the contents of individual human milk samples. The mean contents of each component were as follows: energy, 66.3±13.3 kcal/100 mL; solid matter, 12.46±1.56 g/100 mL; ash, 0.19±0.06 g/100 mL; total nitrogen, 0.19±0.04 g/100 mL; lipids, 3.46±1.49 g/100 mL; carbohydrates, 7.58±0.77 g/100 mL; lactose, 6.44±0.49 g/100 mL; pH, 6.5±0.3; osmotic pressure, 299±14 mOsm/kg·H2O; chloride, 35.9±16.2 mg/100 mL; sodium, 13.5±8.7 mg/100 mL; magnesium, 2.7±0.9 mg/100 mL; phosphorus, 15.0±3.8 mg/100 mL; potassium, 47.0±12.1 mg/100 mL; calcium, 25.0±7.1 mg/100 mL; chromium, 5.9±4.7 μg/100 mL; manganese, 1.1±2.3 μg/100 mL; iron, 119±251 μg/100 mL; copper, 35±21 μg/100 mL; zinc, 145±135 μg/100 mL; and selenium, 1.7±0.6 μg/100 mL. The content of each component varied greatly as the duration of lactation increased. In conclusion, it appears to be necessary to evaluate individual differences of human milk in order to perform valid research regarding infant formula.