Iron transport is strictly regulated by specific carriers at any level:
Input at the body level
Iron, insoluble as free Fe(3+) and toxic as free Fe(2+), is distributed through the body as Fe(3+) bound to transferrin (Tf) for delivery to cells by endocytosis of its complex with transferrin receptor. Iron released from the enterocyte basolateral membrane is sequestered by Tf and transported to sites of utilization and storage. Epatocytes are the major storage site of iron.
The metabolically active cytoplasmic iron is defined as transit/labile iron pool (Iron Crossroad) and it is very short lived. Its fate is, according to local conditions:
Output at the body level