Vitamin B 12 deficiency in untreated celiac disease

Abstract

OBJECTIVES: Iron and folate malabsorption are common in untreated celiac disease as the proximal small intestine is predominantly affected. Vitamin B 12 deficiency is thought to be uncommon, as the terminal ileum is relatively spared. This study aims to investigate the prevalence of vitamin B 12 deficiency in patients with untreated celiac disease. METHODS: Prospective study of 39 consecutive biopsy-proven celiac disease patients (32 women, seven men; median age 48 yr, range 22–77 yr) between September 1997 and February 1999. The full blood count, serum vitamin B 12, red blood cell folate, and celiac autoantibodies (IgA antigliadin and IgA antiendomysium antibodies) were measured before and after a median of 4 months (range 2–13 months) of treatment with a gluten-free diet. In vitamin B 12-deficient patients, intrinsic factor antibodies and a Schilling test, part 1, were performed. RESULTS: A total of 16 (41%) patients were vitamin B 12 deficient (<220 ng/L) and 16 (41%) patients (11 women and five men) were anemic. Concomitant folate deficiency was present in only 5/16 (31%) of the vitamin B 12 patients. The Schilling test, performed in 10 of the vitamin B 12-deficient patients, showed five low and five normal results. Although only five patients received parenteral vitamin B 12, at follow-up the vitamin B 12 results had normalized in all patients. Acral paraesthesia at presentation in three vitamin B 12-deficient patients resolved after vitamin B 12 replacement. CONCLUSIONS: Vitamin B 12 deficiency is common in untreated celiac disease, and concentrations should be measured routinely before hematinic replacement. Vitamin B 12 concentrations normalize on a gluten-free diet alone, but symptomatic patients may require supplementation.