GSTM1 and anemia (phenotype): Although the HRE ratio of the diet containing the lowest iron concentration (12 mg iron/kg diet) was significantly higher (p ≤ 0.05) than the other HIP diet groups based on the mean final hemoglobin at 14 d, only the HIP provided at the two greater concentrations of iron tested in this study (36 and 48 mg iron/kg diets) restored hemoglobin to adequate levels to correct anemia (Hb > 6 g/dL).