EmpeiriaTaking in and storing iron
Clinically: Iron absorption and storage
The body has no way to actively get rid of excess iron, so it controls the amount it absorbs instead. Only a small fraction of dietary iron is taken up, and that fraction rises when stores run low.
unverified These explanations are written to be easy to read and have not yet been checked against a source. The ranges and measurement notes on this page show theirs.
function unverified
Your gut only absorbs a little of the iron you eat, and takes up more when you are running low. There is no way for your body to dump extra iron, so it controls the intake side instead.
Hepatic hepcidin is the master regulator, restricting ferroportin-mediated export from enterocytes and macrophages. Because excretion is not regulated, absorption is the sole control point.
In clinical terms
Duodenal absorption gated by hepatic hepcidin, with storage as ferritin and transport on transferrin.