The Colonic Vitamin D Receptor and Inflammatory Bowel Disease: No Correlation to Histologic or Endoscopic Inflammation.

The role of the vitamin D receptor (VDR) in inflammatory bowel disease (IBD) is poorly described. The aim of this study was to examine the relationship between immunohistochemical VDR expression and IBD activity. The immunohistochemical expression of VDR was analysed in biopsies from active and inactive IBD in 28 patients (ulcerative colitis: 21, Crohn's disease: 7) and 12 non-IBD controls. VDR expression did not change in active compared to inactive disease (p = 0.40 in epithelium and p = 0.29 in stroma). There was a trend for higher VDR expression in controls compared to IBD patients. No relationship was found between VDR expression and histologic inflammation (r = -0.19, p = 0.89 for epithelium and r = 0.13, p = 0.35 for stroma), colonoscopic picture and clinical and laboratory measures including serum 25(OH) vitamin D status (r = -0.91, p = 0.82). IBD disease activity did not correlate to VDR immunohistochemical expression, nor did it differ compared to controls. These results partly conflict with prior studies, but these have only shown modest correlations. Prospective studies investigating VDR activity between IBD and controls should be contemplated.