An orally deliverable dosage system comprises (a) iron in a form of one or more physiologically acceptable iron grades, compounds and/or complexes； and (b) an agent to mitigate one or more gastrointestinal adverse effects of unabsorbed iron, said agent comprising one or both of a zinc component and a chelator component, said zinc component if present comprising one or more physiologically acceptable zinc compounds and/or complexes, and said chelator component if present comprising an ion-chelating compound formulated for release distal to the primary site of iron absorption in the duodenum.
