Nitrogen distribution in human milk from 2 to 16 weeks postpartum

Area of Science:

• Human milk composition
• Lactation physiology
• Nutritional biochemistry

Background:

• Human milk composition changes postpartum.
• Understanding nitrogenous components is crucial for infant nutrition.

Purpose of the Study:

• To analyze the variation in major nitrogen components of human milk.
• To correlate these changes with alterations in total milk nitrogen over time.

Main Methods:

• Collected human milk samples from 10 mothers at 2, 6, 12, and 16 weeks postpartum.
• Quantified total, nonprotein, urea, protein, casein, and whey nitrogen levels.

Main Results:

• Total nitrogen decreased from 2.18 mg/ml at 2 weeks to 1.76 mg/ml at 16 weeks postpartum.
• Nonprotein and urea nitrogen percentages remained constant.
• Protein nitrogen decreased from 1.77 mg/ml to 1.42 mg/ml over the study period.

Conclusions:

• While total and protein nitrogen decline postpartum, nonprotein, whey, and casein nitrogen percentages remain stable.
• Human milk nitrogenous composition shows a consistent pattern despite changes in total nitrogen.