Ascorbic Acid The absorption of iron is enhanced in the presence of vitamin C. Although vitamin C increases the absorption of iron, but the effective amounts required are very large, i.e. about 500 to 1,000 mg. Therefore infants on a normal diet absorb iron better if they are given an extra 100 mg. of ascorbic acid per day.
Oxalic Acid Oxalic acid present in certain vegetables combines with iron and forms insoluble iron oxalate, and thereby prevents the absorption of dietary iron.
Gastric acidity Absorption of iron is impaired in hypoacidity. The presence of anemia and the nature of the food that accompanies the iron are complicating factors. The assimilation of iron may be impaired by rapid emptying of the food from the stomach.