Iron-deficiency anemia in infant development: Implications for growth, cognitive development, resistance to infection, and iron supplementation

Abstract

Iron plays an important role in many metabolic processes, including oxygen transport, oxidative metabolism, and cellular growth. During infancy, inadequate supply of iron resulting in iron-deficiency anemia is associated with morbidity, impaired growth, and decreased behavior and psychomotor development. Although iron requirements during infancy have become better defined, iron-deficiency anemia persists as one of the most common health problems worldwide, a condition that affects approximately 20–25% of the world's infants. Today, much attention is being given to not only preventing iron-deficiency anemia but also to avoiding excessive iron supplementation. There is concern that excessive and widespread iron supplementation could lead to decreased resistance to infection and promotion of gastrointestinal illnesses. However, the literature on the relationship between iron status and chronic infection and disease contains conflicting viewpoints. Some investigators contend that mild iron-deficiency is beneficial for immunity whereas others argue that any deficits in iron status are detrimental. Iron absorption and metabolism are influenced by interactions between iron and other dietary nutrients. Many components of the diet act to inhibit or enhance iron absorption; this information is critical for food fortification programs designed to prevent iron-deficiency anemia worldwide. This paper reviews some of the biological characteristics of iron metabolism and absorption, iron needs during infancy, interactions of iron with other nutrients, methods for hematological assessment, iron-deficiency anemia and growth, the relationship between iron-deficiency anemia and infant psychomotor development, and the impact that iron supplementation has on resistance to infection and gastrointestinal illnesses. The serious consequences of iron-deficiency anemia for infant health, behavior and development, and the widespread prevalence of this disorder are reasons for its prevention. The benefits of oral supplementation of iron appear to outweigh the possibility of iron excess during infancy, a period of rapid growth and development characterized by a marginal dietary supply of iron. Yrbk Phys Anthropol 40:25–62, 1997. © 1997 Wiley-Liss, Inc.