Lipid and trace element composition of human milk.

The recent work on lipids and trace elements in human milk has been reviewed. Lipids in human milk are specially important for the development of the central nervous system of the infant, in addition to being a source of nutrients. Recent studies revealed that the concentration of total lipids was low in milk samples from Indian women belonging to the low socio-economic group: linoleic acid constituted a high percent of the fatty acids. The bile-stimulated lipase activity of milk was higher in Ethiopian than in Swedish milk samples. Vitamin D sulphate, the water soluble conjugate of vitamin D, was present in higher concentrations than that reported for vitamin D in lipid fraction; however, the antirachitic activity of vitamin D sulphate is yet to be studies. Copper, zinc, and magnesium concentrations were high in sampled obtained during the first month of lactation. Copper and zinc levels continued to fall gradually till the end of one year lactation. The mean concentrations of zinc and copper in mature milk samples from Indian mothers were similar to those in American samples, though both the samples showed wide variation. A high proportion of zinc in milk was bound to proteins.