Iron status of infants fed low-iron formula: no effect of added bovine lactoferrin or nucleotides

Abstract

Background: The appropriate level of iron fortification in infant formula remains undetermined. Objectives: We compared hematologic indexes and iron-status indicators in infants who were either breast-fed or fed formula with concentrations of 2 or 4 mg Fe/L and evaluated the effects of providing part of the iron as bovine lactoferrin and of adding nucleotides. Design: Healthy term infants were exclusively breast-fed (n = 16) or fed formula (n = 10–12) from age 4 ± 2 wk to 6 mo. Anthropometric measures were taken monthly, and blood samples were taken at 1, 4, and 6 mo. Hematologic indexes; indicators of iron, zinc, and copper status; and erythrocyte fatty acids were assessed. Results: No significant differences in hematology or iron status were observed between groups at 4 and 6 mo of age. Although 34% of all infants had a hemoglobin concentration Conclusions: A concentration of 1.6 mg Fe/L formula meets the iron requirement of healthy term infants aged ≤6 mo, and providing more iron does not benefit iron stores. Fortification with bovine lactoferrin or nucleotides did not benefit either iron status or erythrocyte fatty acids. Additional studies are needed to establish age-appropriate cutoffs for iron deficiency and iron deficiency anemia in infancy.