Serum vitamin B12 and folate status in patients with inflammatory bowel diseases

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 B12 and folate abnormalities in this entity.

138 patients with IBD (45 Crohn's disease and 93 ulcerative colitis) and 53 healthy subjects were enrolled into the study. Fasting serum B12 and folic acid levels were measured and clinical data regarding inflammatory bowel diseases were gathered.

While the mean serum B(12) concentration in CD patients was 281+/-166pg/ml, the mean serum vitamin B12 concentration in UC patients was 348+/-218pg/ml (p=0.224). The number of patients with vitamin B12 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 B12 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+/-5.3ng/ml in CD patients, 8.6+/-8.3ng/ml in UC patients and 9.9+/-3.3ng/ml in the control group (p=n.s.). Patients with a prior ileocolonic resection had an abnormal B12 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.

Serum vitamin B12 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 B12 level.