Lipids in Human Milk

Abstract

Recent work on lipid classes and the fatty acid composition of milk is reviewed. At least 98% of the lipids are triacylglycerols with about 1% phospholipids and 0.3–0.4% cholesterol. Desmosterol has been identified. The major phospholipids (% of total) are: sphingomyelin (32), phosphatidylcholine (25), and phosphatidyl‐ethanolamine (28). The 12:0 content of colostrum is lower than that of mature milk. The 18:2 content of mature milk can be altered by diet; otherwise, the fatty acid composition is remarkably constant. Long‐chain polyunsaturates appear to be needed for development of the infant's brain and nervous system. Data on the contents of these acids are given. The fat‐soluble vitamins have been analyzed by high‐performance liquid chromatography. The amounts of vitamins D and K in milk, unlike those of A and E, are lower than the quantities required to meet the U.S. Recommended Daily Allowances. Vitamin D sulfate does not appear to be a significant antirachitic component of human milk. Nutritional and analytical aspects are emphasized throughout and areas for future investigations indicated.