There was no significant difference in the prevalence of anaemia between children in the two groups at 12- or 24-month follow-ups (adjusted risk ratio [Adj.RR]: 1.03, 95% CI 0.93–1.13, p = 0.621 and Adj.RR: 1.00, 95% CI 0.90–1.11, p = 0.953), respectively (Table 3); the same was observed in relation to mean Hb. Here, GSTM1 is linked to anemia (phenotype).