title: Effects of formula protein level and ratio on infant growth, plasma amino acids and serum trace elements. I. Cow's milk formula.
abstract: The optimum level and ratios of protein to be used in cow's milk formula has recently been under discussion. Healthy term infants were fed from birth exclusively human milk or a formula that varied in protein level or whey: casein ratio: (A) 1.4 g/dl; 55:45, (B) 1.5 g/dl; 55:45, (C) 1.3 g/dl; 55:45, (D) 1.4 g/dl; 60:40, (E) 1.4 g/dl; 20:80. Infants were followed for 12 weeks and blood samples were taken at 2, 4, 8 and 12 weeks. Anthropometric indices did not show any significant differences among groups. Plasma amino acid and BUN levels of the C group were closest to the breast-fed group, while the formula with the highest protein level (B) resulted in high values for some amino acids. When comparing the formulas with 1.4 g protein/dl, the high casein group had the lowest plasma tryptophan levels. Taurine was added to all formulas at a level similar to that of breast milk; plasma taurine levels were similar for all groups. All formulas contained 0.7 mg iron and 0.7 mg zinc/dl; no differences were found among the groups in hematological indices or serum trace elements. These data show that feeding a formula with 1.3 g protein/dl and 55:45 whey: casein ratio from birth will result in growth and metabolic indices similar to those of breast-fed infants, although some plasma amino acid levels are not identical, 1990.
authors.affiliation: Department of Nutrition, University of California, Davis.
authors.forename: B
authors.initials: B
authors.lastname: Lönnerdal
authors.forename: C L
authors.initials: CL
authors.lastname: Chen
mesh_terms: D000596:Amino Acids / Q000097:blood*; D001827:Body Height; D001835:Body Weight; D001942:Breast Feeding; D002364:Caseins / Q000032:analysis; D004311:Double-Blind Method; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis*; D007231:Infant, Newborn / Q000097:blood / Q000254:growth & development*; D011506:Proteins / Q000032:analysis*; D011897:Random Allocation; D013624:Taiwan; D014131:Trace Elements / Q000097:blood*
chemical_list: D000596:Amino Acids; D002364:Caseins; D011506:Proteins; D014131:Trace Elements