Should we monitor vitamin B₁₂ and folate levels in Crohn's disease patients?

Abstract

Objective. Crohn's disease commonly involves the small intestine, which is the site of vitamin B₁₂ and folate absorption. Our aim was to define the prevalence of vitamin B₁₂ and folate deficiency in patients with Crohn's disease and to identify predictive factors associated with such abnormalities. Methods. Two years prospective study of 180 consecutive Crohn's disease patients. Vitamin B₁₂ and folate deficiency was defined as serum levels below 200 pg/ml and 3 ng/ml, respectively. We analysed prevalence of these deficiencies and possible predictive factors including small intestine resection, disease location, activity and duration of disease. Controls were ulcerative colitis patients (n = 70). Results. The prevalence of B₁₂ deficiency in Crohn's disease was 15.6% (95%CI 9.7–20%) compared with 2.8% (95%CI 0.8–9.8%) in ulcerative colitis (p = 0.007). With regard to folate deficiency, the prevalence in patients with Crohn's disease was 22.2% (95%CI 16–28%) compared with 4.3% (95%CI 1.4–12%) in ulcerative colitis (p = 0.001); 7.8% of Crohn's disease patients had macrocytic anemia. Ileal resection was found to be a risk factor for B₁₂ deficiency (OR 2.7; 1.2–6.7; p = 0.02), and disease activity a risk factor for folate deficiency (OR 2.4; 1.2–5.1; p = 0.01). Conclusion. A significant proportion of patients with Crohn's disease suffer from vitamin B₁₂ and/or folate deficiency, suggesting that regular screening should be performed, with closer monitoring in patients with ileal resection or active disease.

Key Words::

• anemia
• Crohn's disease
• folate
• ileal resection
• vitamin B₁₂

Acknowledgements

We thank McLehm Language Services for kindly reviewing the English used in this paper

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.