Nancy F. Krebs
J. Nutr. 137:511S-517S, February 2007
The primary focus of this review is considerations for complementary feedings to meet micronutrient needs of infants aged 6–24 mo who are continuing with breast-feeding and minimal or no formula. The World Health Organization recommends initiation of complementary feeding to breast-fed infants at ~6 mo of age. Whether complementary foods will meet nutrient needs will depend on the types of food selected. One criterion for the selection of complementary foods is that they be rich sources of zinc and iron because both of these essential micronutrients are critical for normal growth and development, and requirements are not met by exclusive breast-feeding after ~6 mo.
For an exclusively breast-fed 7-mo-old infant, human milk provides ~0.5 mg of zinc, and a little over half of that is absorbed. Adding some cereal can increase zinc intake modestly but will fall short of providing the estimated physiologic requirement because adaptive mechanisms are inadequate to compensate for moderately low zinc intake. Maize, wheat, rice, and roots are also relatively low in zinc and have the added factor of a high phytate-to-zinc molar ratio, which makes the zinc less bioavailable. Meats and liver have greater zinc and iron concentrations than unfortified plant foods and have been shown to have good acceptance by 7-mo-old infants. In contrast to current practices in both developed and developing countries, meats should be considered as an early complementary food for breast-fed infants to provide essential micronutrients.