<prompt> Iron is absorbed predominantly in theStomachDuodenumIleumColon  <response>: Iron absorption occurs predominantly in the duodenum and upper jejunum Muir and Hopfer, 1985 Figure 1. The mechanism of iron transpo from the gut into the bloodstream remains a mystery despite intensive investigation and a few tantalizing hits. Ref: guyton and hall textbook of medical physiology 12 edition 