The purpose of this clinical trial was to determine if high-iron or low-iron formula, containing an average of 12.7 mg/L or 2.3 mg/L respectively, had differing effects on iron status in infancy and on development longitudinally.

For a detailed description of the clinical trial setting and procedures in infancy, please refer to the following:

Walter T, Pino P, Pizarro F and Lozoff B. Prevention of iron-deficiency anemia: Comparison of high- and low-iron formulas in term healthy infants after six months of life. J Pedr 1998:132:635-40.

Inclusion Criteria:

• Birth weight >= 3.0 kg
• single birth
• no major congenital anomalies
• no major birth or neonatal complications
• no emergency c-section
• no jaundice requiring phototherapy
• no hospitalization for more than 5 days
• no chronic illness
• no iron therapy
• already started to received some bottle feedings by 6 months of age

Exclusion Criteria:

• residence outside identified neighborhoods
• another infant <12 months in household
• infant in daycare
• unstable, illiterate, or psychotic caregiver