The purpose of this study is to determine the short (7 days) and long (12 weeks) term effects of oral iron on attention, learning and memory in preschool children. This study is being carried out in two low land villages near the Pacific coast in Guatemala. It includes three groups of preschool children who differ in their body status (as indicated by homoglobin status) as follows: (1) HGB 11.5 grams %; (2) 10 HGB (2) 8 HGB 10. Year one of the study aimed at the recruitment and training of personnel, pretesting of all testing procedures and a collection of all data required by study design. Year two will focus on the analysis of the data, the preparation of the reports thereof, and their submission for publication in scientific journal.