Figure 2. Schematic representation of intestinal iron absorption.

The absorption of iron takes place predominantly in the duodenum. Dietary nonheme iron (mostly Fe³⁺) is reduced to Fe²⁺ form by a ferric reductase. Fe²⁺ then enters enterocytes through DMT1. Depending upon the body's iron status, enterocyte iron can be stored in ferritin or exported into circulation through (FPN1). The exiting iron is reoxidized to Fe³⁺ through a ferrous oxidase (hephaestin) before loading onto Tf.