BIOAVAILABILITY OF IRON FROM IRON PHOSPHATES IN CEREALS AND INFANT FOODS

Bioavailability of iron from ferric orthophosphate and sodium iron pyrophosphate (SIP) used in the fortification of breakfast cereals and infant foods was determined by the rat repletion assay. The relative biological value (RBV%, FeSO4= 100%) of iron from ferric orthophosphate added to breakfast cereals ranged from 33% to more than 60%. The RBV of iron from SIP added to breakfast cereals and infant cereals was found to lie between 14 and 40%. The bioavailability of iron from SIP in two soy-based infant formulas was higher (48 and 57%), indicating the favorable effect of processing. An experimental cereal containing wheat, corn syrup, and honey fortified with SIP gave a value of 78%. When the same specimen of SIP was added to the rat diet containing the unfortified cereal, an RBV of 73% was obtained. The variable bioavailability of iron from these iron phosphates needs to be investigated in regard to their physical-chemical characteristics which affect the bioavailability. © 1979, American Chemical Society. All rights reserved.