GSTM1 and anemia (phenotype): There was no evidence that mean Hb concentration differed between children from the former intervention and control arms (10.79 g/dL; 95%CI: 10.71 g/dL–10.87 g/dL versus 10.83 g/dL; 95%CI 10.74 g/dL–10.90 g/dL) (P = 0.54) The prevalences of anaemia (Hb<11 g/dL) and moderately severe anaemia (Hb<8 g/dLl) were similar in children in the two study arms 678 (51.2%) compared with 631 (48.4%) and 49 (3.7%) compared with 57 (4.7%) respectively (RR: 1.06 95%CI: 0.95–1.18) (P = 0.29) and (RR 0.85; 95%CI: 0.58–1.24) (P = 0.40) (Table 6).