Glycosylated haemoglobin (HbA1c) in iron- and vitamin B12 deficiency.

Glycosylated haemoglobin (HbA1c) was measured in 10 patients with iron deficiency anaemia, 10 patients with vitamin B12 deficiency anaemia and 10 healthy controls. Initially there were no significant differences between the groups (P greater than 0.4), but after treatment with iron and vitamin B12 for 3 and 6 weeks, the glycosylated haemoglobin concentration decreased significantly (P less than 0.01). It was concluded that glycosylated haemoglobin is a sensitive marker of the changes in the erythrocyte population that are observed when predominantly immature erythrocytes are being produced.