R aghavendra Rao M ichael K. G eorgieff Division o f Neonatology, Department o f Pediatrics (RR and MKG) and Institute o f Child Development (MKG), University o f Minnesota

Nutrients and growth factors regulate brain development during prenatal and postnatal life. Animal studies have demonstrated that brief periods of dietary ma­ nipulation, either deficiency (absolute and relative) or supplementation, during a vulnerable period o f brain development could have long-lasting effects on the structure and function o f the brain (Dobbing, 1990; Lucas, 1994). Although such a programming effect has not been conclusively demonstrated in humans, epi­ demiological studies suggest that early nutrition may influence neurodevelopment in humans as well (Lucas, 1998). However, due to its plasticity, a developing brain may also be more amenable to repair following such nutritional perturbations (Dobbing, 1990; Morris, Halliwell, & Bowery, 1989). Furthermore, due to the prioritization o f nutrient delivery to the brain and the filtering effect of the bloodbrain barrier, the developing brain may be spared the adverse effect of nutrient perturbations. Despite such structural brain sparing, nutritional deficiencies may still exert an adverse effect on the functional outcome of neurodevelopment (Georgieff, 1998). For the same regulatory reasons, nutrient overabundance may produce positive, negative, or no effects on the brain. In this chapter, the associa­ tion between nutrients and early neurodevelopment are discussed. The general principles o f research on the interaction between early nutrition and neurodevel­ opment are discussed initially, followed by a brief discussion on the role o f indi­ vidual nutrients on neurodevelopment. Because o f their global significance, two conditions-chronic energy malnutrition and iron deficiency-are reviewed. Fi­ nally, the role of nutrient supplementation on neurodevelopment is discussed.