Studies on iron availability in man, using stable isotope techniques.
1. Iron absorption from 10 mg Fe (as ferrous sulphate), labelled with 1.3 mg 58Fe, was measured in fasting, non-anaemic adult subjects by the faecal-balance technique. The measurement was performed twice, each subject being given, in random order, either 50 mg Fe or a placebo 18 h before the 58Fe-labelled FeSO4. 2. The 50 mg Fe load significantly reduced Fe absorption the following day (P less than 0.01), from a mean of 35.4 (SEM 4.6)% to 29.0 (SEM 5.1)%. This points to the importance of strict dietary control during Fe-absorption studies to eliminate bias in results. 3. In a separate study, the feasibility of using 58Fe-enrichment of erythrocytes, measured by neutron activation analysis (NAA), 10 d after a meal labelled with 0.69 mg 58Fe as an index of Fe absorption was examined. The levels of 58Fe in the blood were detectable by NAA. Regression analysis showed a significant relation between 58Fe-enrichment of blood and 58Fe absorption, calculated as the difference between intake and faecal excretion (R 0.59, P less than 0.05).
Fairweather-Tait
S J
SJ
AFRC Food Research Institute Norwich.
Minski
M J
MJ
D000042:Absorption; D000293:Adolescent; D000328:Adult; D001682:Biological Availability; D004912:Erythrocytes / Q000032:analysis; D005243:Feces / Q000032:analysis; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007501:Iron / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D007503:Iron Isotopes; D008297:Male; D008875:Middle Aged; D009501:Neutron Activation Analysis
D006454:Hemoglobins; D007503:Iron Isotopes; D007501:Iron