A mother's breast milk contains essential fats. It also contains cholesterol. Both are needed by infants to make tissues of the nervous system. The amount of fat in breast milk rises significantly at the end of a breast-feeding session. This may be nature's way of making an infant feel full and stop feeding.
Breast milk contains large amounts of lactose, which is a carbohydrate.
Lactose is used in tissues of the brain and spinal cord, and it provides the infant with energy. Bacteria in the infant's intestines feed on lactose and produce B vitamins. Lactose may also help the infant absorb essential nutrients such as calcium, phosphorus and magnesium. Human breast milk contains only a small amount of iron, but the iron in breast milk is easily absorbed. Breast milk contains all the vitamins an infant needs for good health.