Monitoring dietary compliance in coeliac disease using red cell distribution width.

Red cell distribution width (RDW) as measured on modern blood analysers is a sensitive marker of nutritional deficiency affecting red blood cell production and maturation. Such deficiencies are common in coeliac disease and it may therefore be possible indirectly to assess response to a gluten-free diet by monitoring the RDW. We measured RDW, iron, B12, folate and endomysial antibodies (EMA) in 46 newly diagnosed coeliac patients at diagnosis and after a gluten-free diet. RDW was elevated in 76% of patients at diagnosis. There was a significant decrease in RDW (17.3% vs 13.8%) after 12 months of diet, corresponding to sero-conversion of EMA and normalisation of serum iron, B12 and folate levels. We conclude that monitoring RDW is a simple indirect means of assessing response to a gluten-free diet in coeliac disease.