Severity of anemia was not a factor in deciding to obtain pills: mean Hb did not differ significantly between those who did try to buy the pills (Hb = 14.1 ± 1.13 g/dL) and those who did not (Hb = 14.4 ± 1.05 g/dL). This evidence concerns the gene GSTM1 and anemia (phenotype).