Iron Absorption by Human Milk-fed Premature Infants Receiving Supplemental Iron ♦ 1551

Abstract

To evaluate optimal methods of delivering iron (Fe) to human milk (HM)-fed preterm infants, we measured Fe utilization by 8 HM-fed premature infants[birth weight 1.0 (0.2) kg, gestational age 27 (2) wk, weight at start of study 1.4 (0.3) kg] who were receiving full feedings of human milk fortified with a commercial human milk fortifier. Supplemental Fe was given daily for 7-14 days before the study as 2 mg/kg of ferrous sulfate administered between feedings. On the first study day, 57Fe (2 mg/kg) which had been premixed with a 24-hour supply of fortified HM was fed to the infants, and 58Fe (70 mcg) was administered intravenously (IV). On study day 2, no Fe was mixed with the HM, but 54Fe (2 mg/kg) was administered as ferrous sulfate by orogastric gavage between feedings. Two weeks later, a 1-mL blood sample was collected and red blood cell incorporation (RBC-inc) was calculated from measurement of the isotope enrichment performed using magnetic sector thermal ionization mass spectrometry. Percent absorption was calculated by dividing the RBC-inc of 54Fe and 57Fe by the RBC-inc of 58Fe. All data are mean (SD).