Original article Serum vitamin B 12 and folate status in patients with inflammatory bowel diseases Mustafa Yakut, Yusuf Üstün, Gökhan Kabaçam, Irfan Soykan ⁎ Ankara University Medical School, Ibni Sina Hospital Department of Gastroenterology, Sihhiye, 06100, Ankara, Turkey abstract article info Article history: Received 21 March 2010 Received in revised form 5 May 2010 Accepted 13 May 2010 Available online 8 June 2010 Keywords: Crohn's disease Ulcerative colitis Vitamin B 12 Folate Background: The aims of this study were to investigate the prevalence of serum vitamin B 12 and folate abnormalities in patients with inflammatory bowel diseases (IBD) and to identify risk factors associated with B 12 and folate abnormalities in this entity. Methods: 138 patients with IBD (45 Crohn's disease and 93 ulcerative colitis) and 53 healthy subjects were enrolled into the study. Fasting serum B 12 and folic acid levels were measured and clinical data regarding inflammatory bowel diseases were gathered. Results: While the mean serum B 12 concentration in CD patients was 281 ± 166 pg/ml, the mean serum vitamin B 12 concentration in UC patients was 348 ± 218 pg/ml (p = 0.224). The number of patients with vitamin B 12 deficiency in the CD group was greater than the number of patients with UC [n = 10 (22%) vs. n = 4 (7.5%), p = 0.014]. The number of patients (n =10, 22%) with B 12 deficiency in the CD group was also greater than controls (n =4, 7.5%) (p = 0.039). With regard to folate levels, the median serum folate level was 7.7 ± 5.3 ng/ml in CD patients, 8.6 ± 8.3 ng/ml in UC patients and 9.9 ± 3.3 ng/ml in the control group (p = n.s.). Patients with a prior ileocolonic resection had an abnormal B 12 concentration compared to patients without surgery (p = 0.008). In CD patients, ileal involvement was the only independent risk factor for having a low folate level. Conclusion: Serum vitamin B 12 and folate deficiencies are common in patients with CD compared to UC patients and controls. In CD patients, prior small intestinal surgery is an independent risk factor for having a low serum vitamin B 12 level. © 2010 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. 1. Introduction Vitamin B 12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of disorders. Diagnosis of vitamin B 12 deficiency is typically based on the measurement of serum vitamin B 12 levels [1]. Dietary cobalamin is cleaved from its binding protein by acid and pepsin in the stomach and binds to the R factor, which is produced in the saliva and stomach. This complex travels to the duodenum where cobalamin is cleaved from the R factor by pancreatic proteases and binds to the intrinsic factor (IF), which is also produced in the stomach. The IF–cobalamin compound then travels to the ileum where it binds to a specific receptor, cobalamin, and then is absorbed through the ileal mucosa. Cobalamin (vitamin B 12 ) deficiency is particularly common in the elderly. Any abnormality along the pathway can result in B 12 malabsorption, which in turn can lead to B 12 deficiency [1–5]. Crohn's disease (CD) is a chronic inflammatory disease involving the small and/or large bowel. CD frequently involves terminal ileum, which is the site of B 12 absorption. Long-term inflammation of the mucosa can lead to impaired absorption and can also lead to fibrosis and strictures that necessitate surgical resection of segments of bowel including the ileum, and thus patients with CD may be at particular risk for B 12 deficiency. Ulcerative colitis (UC) is also an inflammatory disease limited to the colon, with little or no ileal involvement, and the prevalence of B 12 deficiency in UC patients is similar to the general population [4,6]. The prevalence of folate deficiency in CD patients was reported as being 0% to 81%. In CD patients, folate deficiency seems to be more common than vitamin B 12 deficiency, specifically in patients on sulfasalazine [4]. The immunosuppressive therapies and possible surgical procedures that the patients might possibly encounter result in the deficiency of vitamin levels. The aims of this study were to define the prevalence of serum vitamin B 12 and folate abnormalities in patients with inflammatory bowel disease and to identify risk factors associated with B 12 and folate abnormalities in CD. 2. Materials and methods In this retrospective and comparative study, a total of 138 patients with inflammatory bowel disease (IBD) (45 CD and 93 UC) were enrolled into the study between January and 2007 December 2009. All patients had the diagnosis of IBD according to clinical, laboratory, endoscopic and histopathological findings. Medical records of all European Journal of Internal Medicine 21 (2010) 320–323 ⁎ Corresponding author. Tel.: +90 312 508 2759; fax: +90 312 310 34 46. E-mail addresses: musyakut@gmail.com (M. Yakut), yusufus@hotmail.com (Y. Üstün), gokhankabacam@yahoo.com (G. Kabaçam), isoykan@medicine.ankara.edu.tr (I. Soykan). 0953-6205/$ – see front matter © 2010 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ejim.2010.05.007 Contents lists available at ScienceDirect European Journal of Internal Medicine journal homepage: www.elsevier.com/locate/ejim