Serum 25-hydroxyvitamin D concentration and inflammatory bowel disease characteristics in Romania

Abstract

Aim: To describe the relationship between vitamin D levels and inflammatory bowel disease (IBD) characteristics in northeastern Romanian patients.

Methods: This was a prospective study of 47 consecutive IBD patients admitted to The Institute of Gastroenterology and Hepatology in Iasi, Romania between March 2011 and June 2012. The diagnosis of IBD was established based on endoscopic, histologic and radiologic findings. Demographic data, disease characteristics, ongoing treatments and biological parameters of patients (including markers of inflammation: C-reactive protein level, fibrinogen level, and erythrocyte sedimentation rate) were recorded. Serum vitamin D levels were measured and compared with age- and sex-matched healthy volunteers from the same geographic area. Vitamin D levels were defined as sufficient (> 30 ng/mL), insufficient (20-30 ng/mL), or severely deficient (< 20 ng/mL).

Results: Thirty-three of the IBD patients included in this study had ulcerative colitis (UC) and 14 had Crohn's disease (CD). Only 24% of the UC patients and 21% of the CD patients had sufficient vitamin D levels. The vitamin D levels were significantly lower in the CD patients with moderate to severe disease activity compared to the CD patients in remission or with mild disease activity (16 ± 6 ng/mL vs 26 ± 7 ng/mL; 16 ± 6 ng/mL vs 31 ± 9 ng/mL, respectively, P < 0.05). Vitamin D levels in the UC patients were not influenced by disease activity and no correlation was observed with the inflammation markers tested (C-reactive protein, fibrinogen, and erythrocyte sedimentation rate). No association was observed between vitamin D levels and smoking status or ongoing medication (5ASA, steroids, and anti-TNFα). Newly diagnosed IBD patients had lower vitamin D levels than patients with established cases, though these differences were not significant (UC: 22 ± 9 ng/mL vs 26 ± 12 ng/mL; CD: 18 ± 6 ng/mL vs 27 ± 11 ng/mL, respectively). Although no association was found between the season during which the visit was scheduled and vitamin D levels, the UC patients assessed during the winter tended to have lower levels than those assessed during the summer (22 ± 9 ng/mL vs 28 ± 13 ng/mL, respectively).

Conclusion: Vitamin D levels are significantly reduced in IBD patients in northeastern Romania, with the lowest levels occurring in CD patients with moderate to severe disease activity.

Keywords: Crohn’s disease activity; Inflammatory bowel disease; Northeastern Romania; Seasonality; Vitamin D level.