BACKGROUND: Estimations of iron absorption from infant formulas are based on 20-year-old data. Data about iron bioavailability from currently used infant formulas are scarce, considering that during the last decades, formulas have had modifications that could affect iron absorption. METHODS: Bioavailability of isotopically labeled iron (55Fe and 59Fe) from several infant formulas administered to contraceptive-using women between the ages of 30 to 50 years was measured. Six infant formulas and one follow-on formula were compared with a powdered, whole cow's milk, and the results were normalized to an absorption of 40% from a reference dose of iron. RESULTS: Iron bioavailability from the infant formulas was consistently higher (19%), contrasting with the low value (4%) of the unmodified cow's milk (p < 0.0001). Iron absorption of the follow-on formula was intermediate (13%). Formulas with 8 mg/l iron and one with 7 mg/l supply approximately 1 mg of absorbed iron, assuming a consumption of 750 ml/day of formula. This amount covers the iron needs of most infants during their period of greatest vulnerability. Formulas containing 12 mg/l iron would allow the absorption of approximately twice the infant iron requirements. CONCLUSIONS: Current infant formulas have a high iron bioavailability, which is an appealing argument for lowering the level of iron fortification in these products.
BACKGROUND: Estimations of iron absorption from infant formulas are based on 20-year-old data. Data about iron bioavailability from currently used infant formulas are scarce, considering that during the last decades, formulas have had modifications that could affect iron absorption. METHODS: Bioavailability of isotopically labeled iron (55Fe and 59Fe) from several infant formulas administered to contraceptive-using women between the ages of 30 to 50 years was measured. Six infant formulas and one follow-on formula were compared with a powdered, whole cow's milk, and the results were normalized to an absorption of 40% from a reference dose of iron. RESULTS:Iron bioavailability from the infant formulas was consistently higher (19%), contrasting with the low value (4%) of the unmodified cow's milk (p < 0.0001). Iron absorption of the follow-on formula was intermediate (13%). Formulas with 8 mg/l iron and one with 7 mg/l supply approximately 1 mg of absorbed iron, assuming a consumption of 750 ml/day of formula. This amount covers the iron needs of most infants during their period of greatest vulnerability. Formulas containing 12 mg/l iron would allow the absorption of approximately twice the infantiron requirements. CONCLUSIONS: Current infant formulas have a high iron bioavailability, which is an appealing argument for lowering the level of iron fortification in these products.
Authors: Thomas Walczyk; Peter Kastenmayer; Stefan Storcksdieck Genannt Bonsmann; Christophe Zeder; Dominik Grathwohl; Richard F Hurrell Journal: Eur J Nutr Date: 2012-09-06 Impact factor: 5.614
Authors: Fernando Pizarro; Manuel Olivares; Eugenia Maciero; Gustavo Krasnoff; Nicolas Cócaro; Diego Gaitan Journal: Nutrients Date: 2015-10-30 Impact factor: 5.717