Vitamin D Deficiency Is Associated with Endoscopic Severity in Patients with Crohn's Disease

Background and Aims Vitamin D deficiency is common in patients with Crohn's disease and is associated with disease activity. Relationship between vitamin D and endoscopic disease activity is unknown. The aim of the study is to determine the association between vitamin D status and endoscopic disease activity in CD patients. Methods Consecutive hospitalized CD patients from 2014 to 2016 who received vitamin D assessment and colonoscopy were retrospectively evaluated. Clinical disease activity was assessed by Crohn's disease activity index and C-reactive protein. Endoscopic activity was calculated using simple endoscopic score for Crohn's disease. Results Median serum 25OHD level of 131 patients was lower than healthy controls [21.1 nmol/L (11.8-32.3) versus 49.9 nmol/L (44.9-57.4), P = 0.007]. 125 (95%) patients had vitamin D deficiency and the rest (5%) had vitamin D insufficiency. Serum 25OHD was inversely correlated with CRP (r = -0.308, P < 0.001), CDAI (r = -0.582, P < 0.001), SES-CD (r = -0.294, P = 0.001), and endoscopic severity stratified by SES-CD (P = 0.001). Conclusion Vitamin D deficiency was prevalent among hospitalized CD patients. Vitamin D levels were inversely correlated with endoscopic disease activity. Vitamin D status could be a biomarker in assessing disease activity among hospitalized CD patients in addition to CDAI and CRP.