GSTM1 and anemia: Anaemia (Hb < 130 g/L in men, <120 g/L in women) was present in 10.8% of 1833 samples analysed, low ferritin (<45 μg/L) in 21.6% of 1851 samples analysed, moderately raised sTfR (>2.3 g/L) was present in 7.6% of the 1875 samples analysed.