The overall goal of this project is to generate evidence to support development of a modality of providing bioavailable iron that does not or produces less adverse effects in iron-replete individuals. The investigators will employ the commonly used iron supplement FeSO4 to compare with two novel forms of iron with features that suggest each may be a useful nutritional source of iron with fewer side effects than FeSO4. The first novel form of iron is a nanoparticulate formulation of iron hydroxide adipate tartrate (IHAT). The second novel form of iron is an organic fungal iron metabolite, Aspiron, which has recently been developed by using a food-grade Aspergillus oryzae cultured in iron-fortified media.