How is heme iron absorbed in the intestinal cells?

Heme iron is absorbed in the intestinal cells primarily through a specific process where it is taken up intact by the enterocytes, the cells lining the intestine. Once inside these cells, heme iron undergoes degradation to release free iron. This free iron can then be utilized by the body for various physiological functions or bound to proteins for transport.

The significance of this process lies in the efficiency of heme iron absorption compared to non-heme iron; heme iron tends to have a higher bioavailability. The degradation in the enterocytes ensures that iron is in a form that can be easily incorporated into storage molecules, like ferritin, or transported to the bloodstream bound to transferrin.

This method of absorption distinguishes heme iron from other forms, which often undergo different pathways and processes. Understanding this mechanism is crucial, as it highlights how dietary choices can influence iron levels and overall health.