GSTM1 and nutritional disorder: Similarly, within a prevalence range of iron deficiency of <28.6%, whole blood ZPP > 99 μmol/mol haem would rule out iron deficiency in 28.6%–36% of children tested; and within a prevalence range of 37.4%, 0.038689 [Hb] + 0.00694 [whole blood ZPP] > 5.93120 would rule out iron deficiency in 37.4%–53.7% of children.