Vitamin D supplement may be helpful in Crohn's disease

Last Updated: 2015-06-22

By David Douglas

NEW YORK (Reuters Health) - Vitamin D supplementation in Crohn's disease (CD) patients in remission is associated with short-term maintenance of intestinal permeability and improvement of markers of disease activity, according to researchers.

As lead author Dr. Tara Raftery told Reuters Health by email, "The study gives some new insights into the mechanisms by which vitamin D may exert beneficial effects in Crohn's disease. This should encourage further research into the role of vitamin D on intestinal barrier and immune function."

In a June 9 online article in the United European Gastroenterology Journal, Dr. Raftery, of St. James's Hospital, Dublin, Ireland, and colleagues noted that although vitamin D supplementation appears to be of benefit in CD, few studies have examined possible mechanisms.

To investigate further, the team randomized 27 CD patients in remission to 2000 IU of vitamin D or placebo daily for three months.

At the end of the study, 25-hydroxyvitamin D (25(OH)D) concentrations were significantly higher in the active treatment group. They also showed stable maintenance of intestinal permeability. In contrast, in the placebo group, they observed significant increases in both small bowel and gastro-duodenal permeability. However, despite the intra-group changes, there were no significant differences in intestinal permeability measures between the groups at three months.

Human cathelicidin (LL-37), which promotes wound healing in intestinal epithelial cells and has other beneficial effects, increased in the active treatment group but did not change significantly in placebo patients. However, there were no significant between-group differences in concentration at three months.

Overall, compared to patients whose 25(OH)D levels were at or below 75 nmol/L, those with higher levels, had significantly lower C-reactive protein, higher quality of life scores, and nonsignificantly lower Crohn's Disease Activity Index scores.

Thus, senior author Dr. Maria O'Sullivan, also of St. James's Hospital, told Reuters Health by email, "While the study is exciting and may translate to improved treatment for CD, we also recognize that there is not yet sufficient evidence to recommend vitamin D as an adjunctive treatment and further randomized controlled trials are needed."

Nevertheless, she concluded, "Currently it seems sensible, that at a minimum, we aim to prevent vitamin D deficiency in people with this disease."

Commenting on the findings by email, gastroenterologist Dr. Helen Pappa told Reuters Health. "Although there are limitations to the study, such as the small number of participants, short duration of follow-up, relatively low dose of vitamin D, and inability to account for confounders due to the small number of participants, it is still an important study, since it investigates the effect of vitamin D, a known immune system regulator, on components of the immune system known to be affected in Crohn's disease. Moreover, this is a prospective study in humans."

"The hope," concluded Dr. Pappa, of St. Louis University School of Medicine, Missouri, "is that these preliminary findings will encourage larger studies to uncover the great potential of vitamin D in the treatment of IBD (irritable bowel disease), adding a novel and less toxic agent to the inventory of IBD therapies."

The Irish Research Council supported this research. The authors declared no competing interests.

SOURCE: http://bit.ly/1Iu9ZAP

United European Gastroenterol J 2015.