Bioavailability in infants of iron from infant cereals: effect of dephytinization

Am J Clin Nutr. 1997 Apr;65(4):916-20. doi: 10.1093/ajcn/65.4.916.

Abstract

Iron bioavailability from an infant cereal made of wheat flour with a low extraction rate (70%) and cow milk was measured in infants by using a stable-isotope technique. A dephytinized infant cereal was prepared by adding commercial phytase during manufacture, resulting in degradation of 88% of the native phytic acid. Paired comparisons were made to evaluate the effect of phytic acid on iron bioavailability. Both infant cereals contained identical amounts of ascorbic acid and had a molar ratio of ascorbic acid to iron of 2:1. Iron was added as ferrous sulfate. No difference in iron bioavailability was observed in this study; the geometric mean was 8.7% (range: 3.8-16.9%) and 8.5% (range: 3.4-21.4%) from the cereal with native phytic acid (0.08% phytic acid) and the dephytinized cereal (0.01% phytic acid), respectively. Dephytinization of infant cereals containing a relatively low native phytic acid content and high amounts of ascorbic acid is thus unnecessary to ensure adequate bioavailability of iron.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • 6-Phytase / pharmacology*
  • Ascorbic Acid / analysis
  • Ascorbic Acid / metabolism
  • Biological Availability
  • Calcium / analysis
  • Calcium / metabolism
  • Dietary Proteins / analysis
  • Dietary Proteins / metabolism
  • Edible Grain / chemistry
  • Edible Grain / metabolism*
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Ferritins / blood
  • Hemoglobins / analysis
  • Humans
  • Infant
  • Infant Food / analysis*
  • Iron, Dietary / analysis
  • Iron, Dietary / pharmacokinetics*
  • Male
  • Phytic Acid / analysis
  • Phytic Acid / metabolism*

Substances

  • Dietary Proteins
  • Hemoglobins
  • Iron, Dietary
  • Phytic Acid
  • Ferritins
  • 6-Phytase
  • Ascorbic Acid
  • Calcium