Absorption of Iron in Young Men Studied by Monitoring Excretion of a Stable Iron Isotope (58Fe) in Feces

Abstract

Fecal excretion of a stable iron isotope (⁵⁸Fe) in five young adult men consuming a diet enriched with the isotope added as an extrinsic tag was investigated as a possible tool for the study of iron absorption. Data are presented to illustrate rapidity and completeness of unabsorbed ⁵⁸Fe excretion. Procedures are outlined to investigate the extent of ⁵⁸Fe re-entry into the gastrointestinal tract of the absorbed ⁵⁸Fe from the label with the cumulative fecal ⁵⁸Fe method and its limitations are discussed. Two methods of estimating ⁵⁸Fe absorption are discussed and compared.