ironregulation

Iron regulation refers to the complex biological processes that control the absorption, transport, storage, and utilization of iron within an organism. Iron is an essential mineral required for numerous vital functions, including oxygen transport by hemoglobin, energy metabolism, DNA synthesis, and immune responses. However, iron is also a potent pro-oxidant, and its excess can lead to cellular damage. Therefore, maintaining iron homeostasis is crucial.

In humans and many other animals, iron regulation primarily occurs at the level of intestinal absorption. When the body needs more iron, the intestinal cells absorb it from the diet. Conversely, when iron stores are sufficient, absorption is reduced. This process is tightly controlled by hormones and signaling molecules. Hepcidin, a peptide hormone produced by the liver, plays a central role. Hepcidin acts by degrading ferroportin, the main iron exporter protein found on the surface of intestinal cells, macrophages, and hepatocytes. High hepcidin levels reduce ferroportin abundance, thus decreasing iron absorption and release from storage. Low hepcidin levels have the opposite effect.

Other factors influencing iron regulation include the body's iron status, inflammatory signals, and erythropoiesis (red blood cell production). For example, inflammation often leads to increased hepcidin production, causing a functional iron deficiency despite adequate iron stores. Disruptions in iron regulation can lead to iron deficiency anemia, characterized by insufficient red blood cells, or iron overload disorders like hemochromatosis, where excessive iron accumulates in organs.