In Vitro Estimation of Relative Iron Availability in Breads and Meals Containing Different Forms of Fortification Iron

ABSTRACT

An in vitro method was used to estimate relative availabilities of eight iron fortification sources under a variety of conditions. The eight iron sources examined were: ferrous sulfate, ferric orthophosphate, ferric sodium pyrophosphate, ferrous fumarate, reduced iron (hydrogen), reduced iron (carbonyl) and two sources of reduced iron (electrolytic). When incorporated into breads or complex meals, seven of the sources tested showed only slight differences in relative availability compared to the ferrous sulfate control. Ferric orthophosphate showed consistently lower relative availability. The baking process did not substantially alter the relative availabilities of nonheme iron in breads and meals containing the different iron fortification sources. Variation in meal composition had a greater influence on the availability of the nonheme iron in the meal than the form of fortification iron incorporated into the meal.