Crohn’s disease is a lifelong inflammatory bowel disease which affects the gastrointestinal tract. The underlying causes are unknown. Low vitamin D levels have previously been implicated in severe attacks. A new randomized, double-blind, placebo-controlled study conducted by Raftery et al. at St James’s Hospital in Dublin, Ireland, indicates that vitamin D supplementation may prolong remission in Crohn’s disease patients.
Low vitamin D status may be associated with Crohn’s disease. Crohn’s disease is a lifelong chronic relapsing and remitting inflammatory condition of the intestine. The inflammation is patchy in nature and can affect any section of the gastrointestinal tract. In Europe, incidences of Crohn’s disease range from 0.7 to 9.8 cases per hundred thousand people a year. There appears to be an association between incidences of Crohn’s disease and latitude, with those in northern climates more likely to develop the condition. Low vitamin D levels have previously been implicated in flareups.
Crohn’s disease patients suffer increased intestinal permeability and impaired barrier function. Measurements of this permeability, in addition to inflammatory markers such as C-reactive protein (CRP), calprotectin, and Crohn’s disease activity index (CDAI), can be taken to evaluate intervention therapy.
In 2013, a pilot study was conducted by Yang et al. (2) in patients with mild to moderate Crohn’s disease in order to determine the dose of vitamin D needed to raise serum vitamin D levels above 40 ng/ml. They found that 24 weeks’ supplementation with up to 5,000 IU/d vitamin D3 effectively raised serum 25(OH)D3 levels and reduced CDAI scores in a small cohort of Crohn’s patients (14 of 18 participants).
A new randomized, double-blind, placebo-controlled study has recently been conducted by Raftery et al. (1) at St James’s Hospital in Dublin, Ireland, with a cohort of 27 Crohn’s disease patients, who were in remission at the time of the study. A daily intervention of 2,000 IU/day vitamin D taken for three months was found to raise the 25(OH)D plasma concentration to ≥ 75nmol in eight of the 12 participants. None suffered any relapses. Over this period, the intestinal permeability of the placebo group increased significantly, whereas there was no change in permeability in the intervention group. The intervention group also had lower levels of CRP and significantly improved standards of self-reported Quality of Life. The CDAI also fell, but did not achieve statistical significance.
This pilot study has provided useful evidence to suggest that a daily dose of 2,000 IU per day of vitamin D may help to prevent relapses of inflammatory attacks in Crohn’s disease patients. Further, it has shown an association between reductions in gut permeability and inflammatory markers, and increased serum 25(OH)D levels.