Define Solubility affecting absorption of dietary iron?
Solubility is crucial for non-haem iron absorption as the inorganic iron salts have to be solubilized in the intestine for the iron to be taken up by the muscosal cells. The acidic pH of the stomach makes iron soluble. However, as the chyme passes into the small intestine, the rising pH tends to precipitate iron as femc hydroxide complexes, the presence of ascorbic acid and other organic acids in the small intestine solubilize to chelate the iron so that it can be absorbed. Ferrous salts are more soluble than ferric salts and are therefore better absorbed.