GSTM1 and anemia: IQR: interquartile range; IDA: iron deficiency anemia; RBC: red blood cell; Hb: hemoglobin; MCV: mean corpuscular volume; MCH: mean corpuscular hemoglobin; RDW: red cell distribution width; RDWI: red cell distribution width index; MI: Mentzer index; Plt: platelets; WBC: white blood cell; CRP: C-reactive protein