Reducing agents and absorption of iron

IRON absorption has been shown to be increased by a variety of substances. Ascorbic acid is perhaps the best known of these¹. The activities of inosine², succinic acid³, fructose⁴ and cysteine^5,6 have been discovered more recently. Several different hypotheses have been offered in explanation of the action of these substances. (1) That ferrous iron is more readily absorbed than ferric iron and that the ferrous form is maintained by an intra-luminal intestinal reducing agent (ascorbic acid); (2) that iron transport is linked with oxidative metabolism (succinic acid); (3) that iron transport depends on a carrier or chelating agent (fructose, cysteine).