Vitamin D deficiency associated with mucosal inflammation in UC – Healio
Serum 25 hydroxyvitamin D concentrations were inversely associated with mucosal inflammation and disease activity in patients with ulcerative colitis, according to the results of a prospective study.
“Patients with inflammatory bowel disease have a high prevalence of vitamin D deficiency,” Joel Pekow, MD, assistant professor of medicine from the section of gastroenterology at University of Chicago Medicine, told Healio Gastroenterology. “In murine models, over-expression of mucosal [vitamin D receptor] protects against colitis by improving epithelial barrier integrity. Less is known regarding the impact of vitamin D deficiency on mucosal inflammation in patients with ulcerative colitis.”
Therefore, Pekow and colleagues evaluated serum 25 hydroxyvitamin D [25(OH)D] concentrations in 230 prospectively enrolled UC patients (mean age, 45.8 years; mean disease duration, 16.6 years; 53% men; 90% white), and compared them with their Mayo endoscopic scores, total Mayo scores and histologic activity.
They also compared colonic mucosal expression concentrations of epithelial junction proteins and proinflammatory cytokines between patients with low or high serum 25(OH)D concentrations to determine whether sufficient vitamin D levels are associated with the preservation of epithelial junctional proteins and reduced mucosal inflammatory cytokines.
They found that “the vast majority of patients with ulcerative colitis have vitamin D deficiency or insufficiency, [and] mucosal inflammation in patients with ulcerative colitis is associated with a decrease in serum 25(OH)D levels,” Pekow said. The overall mean serum 25(OH)D concentration was 21.8 ng/mL, and serum 25(OH)D concentrations showed significant inverse associations with Mayo endoscopy scores (P = .01), total Mayo scores (P = .001) and histologic activity (P = .02).
Moreover, serum 25(OH)D concentrations less than 20 ng/mL were associated with reduced mucosal transcript and protein expression concentrations of vitamin D receptor (VDR), E-cadherin and occludin, and also decreased protein expression of zonula occluden 1. Conversely, mucosal transcript expression concentrations of the pro-inflammatory cytokines TNF-alpha and interleukin 8 were increased in patients with serum 25(OH)D concentrations less than 20 ng/mL.
“In patients with UC, serum 25(OH)D levels correlate with mucosal expression of VDR and epithelial junction proteins and inversely with pro-inflammatory cytokines, supporting the notion that vitamin D is protective of active inflammation in UC,” Pekow said.
Study limitations include an observational study design that could not establish a causative relationship between low serum 25(OH)D and mucosal inflammation; a cohort likely to have more severe UC than the general UC population; and a lower serum 25(OH)D level cutoff than is typically used to define vitamin D sufficiency/deficiency, the researchers wrote.
“The findings of this study support routine monitoring of serum vitamin D levels in patients with ulcerative colitis,” Pekow said. “As increased 25(OH)D levels are associated with less severe disease activity and improvement in markers of intestinal barrier integrity, these results support investigation into the clinical effectiveness of vitamin D treatment on mucosal inflammation in patients with ulcerative colitis.” – by Adam Leitenberger
Disclosures: The researchers report no relevant financial disclosures.