American researchers found that a lower vitamin D concentration in the blood is associated with increased endoscopic and histological disease activity in patients with ulcerative colitis.
Ulcerative colitis (UC) is a chronic inflammatory bowel disease that affects the colon. UC has a multifactorial origin, but vitamin D deficiency might be one possible factor in its development. Vitamin D is known to have anti-inflammatory effects by suppressing immune-cell activation and cell death through the activation of vitamin D receptors (VDR). In addition to this, vitamin D may have an important role in maintaining the integrity of the intestinal epithelial barrier as well.
In a new article published in The American Journal of Clinical Nutrition a research group investigated the association between vitamin D concentrations in the blood and both histological and clinical disease activity in patients with UC. 230 patients with UC diagnosis were included in the study. At the beginning of the study, data on the subject’s age, disease duration, family history of inflammatory bowel disease, smoking status, and history, as well as current medication and dose, including vitamin D supplementation, were collected. Endoscopy and biopsy were performed to determine endoscopic and histologic severity of the disease. At baseline, vitamin D concentration was measured from peripheral blood.
The mean serum vitamin D concentration was 21.8 ng/mL, below the sufficient amount. There was a significant inverse association between mean serum vitamin D concentration and both endoscopic and histologic disease activity. In patients with no histologic inflammation, vitamin D concentrations were significantly higher than in patients with inflammation. After controlling for other factors (sex, treatment, smoking, etc.), higher vitamin D serum concentration correlated with a decrease in disease activity.
Furthermore, subjects with high vitamin D concentration had an increased intestinal VDR expression and higher expression of proteins responsible for maintaining the epithelial barrier in the colon. There was a significant inverse association between serum vitamin D concentration and the expression of pro-inflammatory proteins in colon samples, so a higher vitamin D concentration may be protective against inflammation.
It seems that serum vitamin D concentration has an important role in the development and disease activity of UC, and therefore, it is extremely important to reach a sufficient serum vitamin D level in patients with inflammatory bowel disease.
Written By: Dr. Fanni R. Eros