Development of rat and mouse models of HI absorption involved 3 distinct phases, which tested the ability of dietary HI to (a) correct iron-deficiency anemia (IDA) in WT rats and mice; (b) provide the extra iron required to support pregnancy, lactation, and neonatal development in WT animals; and (c) contribute to iron loading in hepcidin-KO (Hamp-KO) rats and mice, modeling hereditary hemochromatosis (HH). This evidence concerns the gene HAMP and hereditary hemochromatosis.