What is the Origin of Heme Iron Bioavailability?

Heme is a term from biochemistry referring to the iron-containing prosthetic group in hemoglobin. Iron is the essential mineral. Bioavailability is a pharmacological term describing the fraction of an administered dose that reaches the systemic circulation.

What is the Mechanism of Heme Iron Bioavailability?

Heme iron is absorbed intact into the enterocytes of the small intestine via a dedicated, distinct transport system, unlike non-heme iron which requires reduction and separate transporters. This unique mechanism bypasses many inhibitory dietary factors, resulting in a significantly higher absorption rate. Once inside the enterocyte, the iron is released from the heme structure and then transported into the bloodstream via ferroportin, where it binds to transferrin for systemic distribution.

Heme Iron Bioavailability

Meaning

The degree and rate at which iron, specifically in the highly absorbable heme form derived from animal protein, becomes available at its physiological site of action following ingestion. Maximizing this bioavailability is crucial for efficient erythropoiesis and preventing iron deficiency.