The main findings are: (1) no interaction between IPT of malaria and CF on Hb concentration, anaemia or ID; (2) iron fortified CF had no effect on Hb concentration or anaemia prevalence but substantially decreased the prevalence of ID; (3) IPT of malaria modestly reduced anaemia; and (4) iron fortification with FeFum or FePP had the same effect on Hb concentration, although anaemia decreased more in children receiving FePP. The gene discussed is GSTM1; the disease is malaria.