What protein regulates iron absorption in the body?

What protein regulates iron absorption in the body? Hepcidin is the key protein hormone that controls how much iron enters the bloodstream.

Made mainly by liver cells, hepcidin regulates ferroportin, the cellular channel that exports iron. When hepcidin binds ferroportin, the channel is internalized and broken down. This traps iron inside intestinal cells, macrophages, and liver cells, reducing its release into the blood.

Hepcidin production rises when iron stores are high and during inflammation. That response helps limit iron available to invading microbes, but persistently high hepcidin can contribute to anemia of chronic inflammation. When hepcidin is unusually low, intestinal absorption and iron release increase, contributing to iron overload disorders such as hereditary hemochromatosis.

A common mix-up is confusing hepcidin with ferritin or transferrin. Ferritin stores iron inside cells, while transferrin transports iron through the blood. Hepcidin is the regulator that controls iron export by acting on ferroportin. The HAMP gene encodes human hepcidin, which was identified in the early 2000s.