Define Absorption of Dietary Iron?
Haem iron is more bioavailable than non-haem iron because it is absorbed intact as a soluble complex by endocytosis (process whereby cells absorb material, molecules such as proteins, from outside by engulfing it with their cell membrane). Non-haem iron, on the other hand, forms insoluble complexes with many components concurrently present in the diet, rendering the iron unavailable for mucosal uptake. The absorption of iron also depends on the iron status of the individual and on the availability of an iron-binding mucosal transport protein (transferrin) to facilitate the uptake from the intestines.