This shifted the balance of evidence on safety, because a prior summary of placebo-controlled randomized iron supplementation trials conducted in malaria-endemic populations with iron deficiency anemia (IDA) had shown that iron supplementation resulted in a Hb increase of 1.25 g/dL (95% CI 1.20–1.30) and did not significantly increase the risk of a clinical malaria attack [37]. The gene discussed is GSTM1; the disease is anemia.