A Substantial Proportion of 6- to 12-Month-Old Infants Have Calculated Daily Absorbed Iron below Recommendations, Especially Those Who Are Breastfed

Abstract

Objective: To calculate the amount of bioavailable iron consumed among 6- to 12- month-old infants considering differences in iron bioavailability among dietary iron sources and to compare this with current recommended intakes. Study design: We used the Feeding Infants and Toddlers Study database of dietary intakes from 2016 and the estimated bioavailability of dietary iron sources to evaluate the proportion of infants whose calculated total daily absorbed iron fell below physiologic requirements, that is, the recommended amount needed to fully support growth and erythropoiesis. Results: The calculated daily iron absorption was below the recommended amount in 54.3% of infants evaluated ranging from 19.5% of 448 exclusively formula-fed infants, to 95.8% of 296 exclusively breastfed infants and 72.2% of 102 mixed fed infants. The calculated mean iron absorption of 6- to 9- month-old breastfed infants was 0.27 mg/day, far less than the estimated physiologic requirement of 0.69 mg/day. The most highly bioavailable iron, heme iron, was <12% of the contributor to total iron absorbed in breastfed infants. Conclusions: These data indicate a need for further education and public health policies to support increased iron intake in 6- to 12- month-old infants, emphasizing those receiving any breast milk. Exclusively formula-fed infants are at lower risk, but rates of low absorbed iron indicate that all infants may need monitoring for clinical evidence of low iron status. Consideration should be given to increasing the proportion of heme iron obtained from animal products in the diet where feasible.