GSTM1 and anemia: We analysed differences between intervention groups in mean Hb, ZPP, and sTfR at 36 gw, and the proportion with anaemia (Hb < 100 g L−1) and iron deficiency (ZPP > 60 μmol mol−1 haem or sTfR > 6 mg L−1) at 36 gw.