Equivalent effects on fecal reactive oxygen species generation with oral supplementation of three iron compounds: ferrous sulfate, sodium iron EDTA and iron polymaltose.

BACKGROUND In any context of iron supplementation in the prenatal prophylaxis or therapeutic dosage range, a large amount will remain unabsorbed and pass through the intestinal tract into the colonic digesta possibly causing increased oxidation. AIM To compare the generation of fecal reactive oxygen species (ROS) in situ after daily consumption of 100 mg of elemental iron in three frequently used forms of iron supplements. METHODS Ten healthy, iron-repleted adult males were investigated before and during supplementation with three oral iron compounds: 100 mg of oral iron were given as ferrous sulfate, Na Fe-EDTA and iron polymaltose for 6 days to each subject in an individually stratified sequence. Stool samples were collected and analyzed for iron content and the in situ generation of fecal ROS. RESULTS Significant increases in fecal ROS generation were observed during oral iron supplementation. No statistical differences were seen in either residual concentrations of non-heme iron in stool or the level of fecal ROS generation between the three Fe compounds. There was, however, a significant association between the iron concentration in the stool and ROS generation. CONCLUSION In spite of the differences in their chemical characteristics, none of the three distinct iron complexes reduced oxidative stress in the intestinal lumen.