Furthermore, patients in the study by Bager et al had less severe anaemia and IDA than the patients in the study presented here (mean Hb at baseline 10.1 and 9.7 g/dL in the oral and iv iron group respectively; mean ferritin 174 and 161 μg/L; mean TSAT 21% and 20%). This evidence concerns the gene GSTM1 and anemia (phenotype).