Prevalence of and Risk Factors for Vitamin B12 Deficiency in Patients with Crohnʼs Disease

Abstract

Purpose: Crohn's disease is an inflammatory condition of the GI tract that can commonly involve the terminal ileum which is the site of B12 absorption. The aim of this study was to define the prevalence of vitamin B12 deficiency in a population with Crohn's disease and to identify risk factors associated with B12 deficiency. Methods: Medical records of 201 patients with Crohn's disease evaluated at a tertiary care center were retrospectively reviewed to determine the prevalence of B12 deficiency and to evaluate for risk factors associated with B12 deficiency. The prevalence of B12 deficiency in a control population of 40 patients with ulcerative colitis was also assessed. Results: The prevalence of an abnormal B12 level in patients with Crohn's disease was 18.4% (95% CI 13.1–23.8%) compared with 5% (95% CI 0–11.8%) (p=.035) in ulcerative colitis controls. Risk factors for B12 deficiency in patients with Crohn's disease included prior ileal (OR, 7.22; 95%CI 1.97–26.51) or ileocolonic (OR, 5.81; 95% CI 2.09–16.12) resection and the need for ongoing medical therapy (OR, 2.59; 95% CI 1.03–6.47). Neither disease location nor duration was independently associated with the risk of B12 deficiency. Conclusions: Abnormal B12 levels are common in patients with Crohn's disease. Given the complications that can be seen with low B12 levels, and the high prevalence in this population, we would advocate that patients with Crohn's disease be screened for B12 deficiency as part of the ongoing care for the management of the Crohn's disease. Special attention should be given to those that have had a prior ileal or ileocolonic surgery.