title: α-Lactalbumin and casein-glycomacropeptide do not affect iron absorption from formula in healthy term infants.
abstract: Iron absorption from infant formula is relatively low. α-Lactalbumin and casein-glycomacropeptide have been suggested to enhance mineral absorption. We therefore assessed the effect of α-lactalbumin and casein-glycomacropeptide on iron absorption from infant formula in healthy term infants. Thirty-one infants were randomly assigned to receive 1 of 3 formulas (4 mg iron/L, 13.1 g protein/L) from 4-8 wk to 6 mo of age: commercially available whey-predominant standard infant formula (standard formula), α-lactalbumin-enriched infant formula (α-LAC), or α-lactalbumin-enriched/casein-glycomacropeptide-reduced infant formula (α-LAC/RGMP). Nine breast-fed infants served as a reference. At 5.5 mo of age, (58)Fe was administered to all infants in a meal. Blood samples were collected 14 d later for iron absorption and iron status indices. Iron deficiency was defined as depleted iron stores, iron-deficient erythropoiesis, or iron deficiency anemia. Iron absorption (mean ± SD) was 10.3 ± 7.0% from standard formula, 8.6 ± 3.8% from α-LAC, 9.2 ± 6.5% from α-LAC/RGMP, and 12.9 ± 6.5% from breast milk, with no difference between the formula groups (P = 0.79) or all groups (P = 0.44). In the formula-fed infants only, iron absorption was negatively correlated with serum ferritin (r = -0.49; P = 0.005) and was higher (P = 0.023) in iron-deficient infants (16.4 ± 12.4%) compared with those with adequate iron status (8.6 ± 4.4%). Our findings indicate that α-lactalbumin and casein-glycomacropeptide do not affect iron absorption from infant formula in infants. Low serum ferritin concentrations are correlated with increased iron absorption from infant formula.
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia. ewa.szymlekgay@deakin.edu.au
authors.forename: Ewa A
authors.initials: EA
authors.lastname: Szymlek-Gay
authors.forename: Bo
authors.initials: B
authors.lastname: Lönnerdal
authors.forename: Steven A
authors.initials: SA
authors.lastname: Abrams
authors.forename: Anne S
authors.initials: AS
authors.lastname: Kvistgaard
authors.forename: Magnus
authors.initials: M
authors.lastname: Domellöf
authors.forename: Olle
authors.initials: O
authors.lastname: Hernell
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000097:blood; D002364:Caseins / Q000494:pharmacology*; D004032:Diet; D004920:Erythropoiesis / Q000187:drug effects; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D007227:Infant Nutritional Physiological Phenomena / Q000187:drug effects*; D007408:Intestinal Absorption; D007501:Iron / Q000097:blood / Q000493:pharmacokinetics*; D000090463:Iron Deficiencies; D019266:Iron, Dietary / Q000493:pharmacokinetics*; D007768:Lactalbumin / Q000494:pharmacology*; D008297:Male; D009752:Nutritional Status / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D012016:Reference Values
chemical_list: D002364:Caseins; D019266:Iron, Dietary; D010446:Peptide Fragments; C065989:caseinomacropeptide; D005293:Ferritins; D007768:Lactalbumin; D007501:Iron