Define about the Absorption of Iron?
Before it can be absorbed, iron whether it is in the form of haem or non-haem must be released from the food matrices where it is bond with other constituents. Proteases (the enzyme) in the stomach and small intestine hydrolyze haem iron from the globin portion of haemoglobin or myoglobin. In the case of non-haem iron, gastric secretion including HCl and pepsin aid its release from food components.
Most non-haem iron is present in the ferric form which is reduced to ferrous form in the acidic environment of the stomach. However, as the ferrous iron passes into the small intestine (alkaline pH), some Fe2+ may be oxidized to become ferric iron. Following its liberation from food components, absorption' takes place. Like other minerals, iron is also absorbed in duodenum and upper jejunum.