Table 4 shows the characteristics of the different iron formulations available and Table 5 the advantages and limitations of oral versus intravenous iron. Figure 6 shows a simple algorithm for calculating the dose of iron to be administered based on the patient’s weight and hemoglobin level. This pragmatic approach is easier to apply than the classical Ganzoni formula, which, in some contexts, may underestimate the real iron needs.Ganzoni Equation for Iron Deficiency AnemiaTotal, iron deficit (mg) =Body weight (kg) × (Target Hb − Actual Hb) [g/dL] × 2.4+iron stores (mg). This evidence concerns the gene GSTM1 and nutritional disorder.