D. - Regional Variations in the Composition of Human Milk

Abstract

This chapter discusses regional variations in the composition of human milk. The composition of human milk varies among different parts of the world and different women living in the same locality. The composition of milk changes dramatically during the first days after a birth as the secretion changes from colostrum to milk. After the first 1 or 2 weeks, the composition stabilizes and further changes are less marked and occur over a longer timeframe. To facilitate direct comparisons between studies from different parts of the world, the data in the tables have been grouped into the following periods of lactation: colostrum, transitional, and mature. Each data entry is accompanied by the stage of lactation as detailed by the investigators. The concentration of certain milk components, especially fat, varies substantially during a feed and throughout the day. The composition of milk appears to be dependent on the parity and the age of the mother. In recent years, the analysis of most minerals in breast milk has been conducted using atomic absorption spectrometry, or an equivalent method, with the inclusion of standardized reference materials. Published concentrations are expressed in a variety of forms. For consistency, all the data have been expressed as weight per unit volume of milk.