In both groups, regardless of CKD status, mean levels of serum iron, serum ferritin, TSAT, and hepcidin-25 increased, TIBC and sTfR decreased, and mean levels of Hb, red blood cell count, hematocrit, MCV, MCH and MCHC increased from baseline to week 8 and EOT (Table 2 and Supplementary file 1). This evidence concerns the gene GSTM1 and chronic kidney disease.