Bioavailability to rats of iron from fortified grain amaranth

In this study, fortified and unfortified grain amaranth seed flour diets and a FeSO4-fortified casein diet (used as a control) were evaluated for their iron (Fe) bioavailability. NaFeEDTA, ferrous fumarate, and FeSO4-fortified grain amaranth were fed to growing Sprague-Dawley weaning male rats. Iron intake, hemoglobin iron (HbFe) gain, Fe availability, total iron binding capacity (TIBC), serum iron, non-haem liver iron and red bloodcell volume (RBV) were determined, and the values were compared with those of the FeSO4-fortified casein diet control. Ferrous fumarate fortified diets gave consistently high values for all these parameters, compared with consistently low values for the amaranth diet without iron fortification. Relative biological values (RBVs) were 0.40, 1.55, 1.75, 1.67 and 1.00 for animals fed on an unfortified amaranth diet, and diets fortified with NaFeEDTA, ferrous fumarate, FeSO4 and casein fortified with FeSO4, respectively. Using FeSO4-fortified casein as control, ferrous fumarate gave a superior RBVs (1.75 vs. 1.00). The RBVs, of the unfortified cereal diets were 40% that of the control, perhaps suggesting low iron absorption from the amaranth cereal. Based on the results of this study, amaranth cereal can be considered an idea food vehicle for iron fortification. The iron fortification of choice is ferrous fumarate.