Iron and copper absorption in young and elderly men

Abstract

Six healthy young men were confined to a metabolic unit to study iron and copper absorption from constant diets containing 10 mg of iron and 3 mg of copper daily. Iron status of all the men was normal. The men were confined to a metabolic unit for 78 days. Absorption was determined twice during the study using iron and copper enriched with the stable isotopes 54Fe and 65Cu. Stable isotopes were analyzed by magnetic sector, thermal ionization mass spectrometry. Iron and copper balances were determined for two 21 day periods and blood parameters of iron and copper status were measured at the beginning and end of the study. Data of the young men were combined with data of elderly men studied earlier. Blood indicators reflected adequate iron status in all subjects at the end of the study and serum copper was in the normal range for all subjects. The following indicators of iron status differed significantly among subjects: hemoglobin, hematocrit, TIBC, ferritin, and serum transferrin. Urinary and serum copper also differed significantly among subjects. Neither iron nor copper absorption differed between age groups or study periods. Iron absorption differed significantly among individuals, but copper absorption did not.