Oral supplementation with ferrous sulfate but not with non-ionic iron polymaltose complex increases the susceptibility of plasma lipoproteins to oxidation

Abstract

Iron deficiency anemia is customarily treated by iron supplementation. However, iron can act as a catalyst of lipid peroxidation in vitro, and high intake of heme iron has been associated with an increased risk of myocardial infarction in some, but not in all epidemiologic studies. We carried out a 6-month trial of the effects of supplementation of men (n=48) with low iron stores with ferrous sulfate (180 mg of iron per day), iron polymaltose complex (200 mg of iron per day) or placebo. The in vitro susceptibility of very low and low density lipoproteins to oxidation increased in the ferrous sulfate group by 8.8% (P<0.05) compared to placebo and by 12.8% (P<0.05) compared to iron polymaltose complex. The produced amount of a lipid peroxidation product increased in the ferrous sulfate group by 13.8% (P<0.05) compared to the iron polymaltose complex group. This study suggests a role for ionic rapidly absorbed and distributed iron in oxidation susceptibility of lipoproteins in humans. Our findings have implications regarding the treatment of iron deficiency anemia. They indicate that a rapid correction of iron stores by supplementation with high dose ferrous sulfate, at least in combination with ascorbate, can have undesirable effects and suggest that if iron supplementation is necessary, non-ionic iron polymaltose products are preferable to ferrous sulfate.