RCT using ferrous fumarate (FeF) as an Fe compound showed stronger effect on Fe status with higher Hb and serum ferritin (SF) concentration and reduced anaemia and ID in infants receiving additional 5·5 or 12·5 mg Fe/d from a micronutrient-fortified maize porridge compared with their control peers(14,25). The gene discussed is GSTM1; the disease is anemia.