• Although some studies suggest that maternal nutrition may affect the immunologic components in human milk, no studies address the effect of such changes upon the susceptibility of the recipient infant to infectious diseases.

• Breastfeeding appears to protect against food allergy and eczema, but the protective mechanisms are not understood well. The subcommittee concluded that to reduce the chance of allergy or colic in their breastfed infants, mothers should not avoid important food sources of nutrients such as cow's milk in the absence of objective evidence provided by oral elimination-challenge trials (see later section "Maternal Diet"). Although there are some reports of untoward reactions in breastfed infants linked to extrinsic food allergens in human milk, the use of food allergen-restricted diets in pregnancy, lactation, or both should be limited to those cases for which the sensitization has been proven.

• Recent epidemiologic studies suggest that breastfeeding may lessen the risk of developing certain chronic diseases (such as lymphoma, Crohn's disease, and type I diabetes mellitus) later in life.

• Current evidence does not warrant the conclusion that breastfeeding will prevent obesity in the offspring.

• The effects of breastfeeding on infant and childhood mortality in the United States deserve study, especially among subgroups with higher than average mortality rates.

• In general, human milk has not been shown to transmit infections, but more research will be required to ascertain the risk to the recipient of HTLV-1 in human milk and whether HIV-1 is a major infectious agent in human milk.

The following steps should be taken to ensure adequate nutrition of breastfed infants:

• All newborns should receive a 0.5- to 1.0-mg injection or a 1.0-to 2.0-mg oral dose of vitamin K immediately after birth, regardless of the type of feeding that will be offered the infant.

• The infant should be given a 5.0- to 7.5-µg supplement of vitamin D per day if his or her exposure to sunlight appears to be inadequate.

• Fluoride supplements should be provided only to breastfed infants who live in households in which the fluoride content of the water supply is low (<0.3 ppm).

• Human milk is a sufficient source of iron for the first 6 months of an infant's life, but foods with bioavailable iron, iron-fortified foods, or a low-dose iron supplement should be provided at 6 months, or earlier if supplementary foods are introduced before that time.