Anaemia is typically the first clue to iron deficiency, but an isolated haemoglobin
measurement has both low specificity and low sensitivity. The latter can be improved by
including measures of iron-deficient erythropoiesis such as the transferrin iron saturation,
mean corpuscular haemoglobin concentration, erythrocyte zinc protoporphyrin, percentage
of hypochromic erythrocytes or reticulocyte haemoglobin concentration. However, the
changes in these measurements with iron deficiency are indistinguishable from those seen …