Crohn’s disease (CD) is an inflammatory bowel disease (IBD). CD causes inflammation of the lining of the digestive tract, which can lead to abdominal pain, severe diarrhea, fatigue, weight loss and malnutrition. Inflammation caused by CD can involve different areas of the digestive tract depending on the individual.
The inflammation that results from CD often spreads deep into the layers of affected bowel tissue. Not only can CD be painful and debilitating, but it may also lead to life-threatening complications.
There is no known cure for CD, but various therapies can reduce its signs and symptoms. In some cases, treatment can even lead to long-term remission.
The incidence of CD is increasing all around the world. In Europe, the incidence of inflammatory bowel disease has increased from 1.0 per 100,000 person-years in 1962 to 6.3 per 100,000 person-years in 2010.
CD is more common in countries far from the equator, but season-of-birth and seasonality studies have been mixed. A number of studies have found lower 25(OH)D levels in patients with CD compared to controls. Studies have also found 25(OH)D levels are associated with disease severity.
In 2011, a poster at the Washington DC American College of Gastroenterology meeting, presented the findings from
Dustin Boothe, Harrison Lakehomer, Vinita Jacob, Ellen Scherl, and Brian Bosworth, of Weill Cornell Medical College, New York, NY, that 10,000 IU/day was superior to 1,000 IU/day in reducing disease severity.
In 2013, we wrote about an open label trial that showed approximately 5,000 IU/day of vitamin D significantly reduced disease severity and increased quality of life in CD.
Now Maria O’Sullivan and colleagues, Department of Clinical Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Dublin, Ireland has recently treated 27 patients with CD in a randomized controlled trial. The trial compared treatment with 2,000 IU/day to placebo treated patients.
Raftery et al. Effects of vitamin D supplementation on intestinal permeability, cathelicidin and disease markers in Crohn’s disease: Results from a randomised double-blind placebo-controlled study. United European Gastroenterology Journal June 2015 vol. 3 no. 3 294-302.
At 3 months, mean 25(OH)D levels in the treatment group were 36 ng/ml compared to the placebo group of 16 ng/ml (p< 0.001). In the treatment group, 4 participants did not obtain serum 25(OH)D concentrations of 30 ng/ml at 3 months. All of those in the placebo group had 25(OH)D concentrations < 30 ng/ml at 3 months.
When analyzed according to 25(OH)D concentrations achieved at 3 months, the subjects whose levels were > 30 ng/ml had significantly lower gastro-duodenal permeability (p = 0.030), better quality of life (p < .03), lower CRP levels (p > 0.02), higher concentrations of cathelicidin, (p < 0.001) and non-significantly better disease severity markers (p= .08). Cathelicidin is an antimicrobial peptide which aids in fighting bacteria. Interestingly, the difference in cathelicidin concentrations were more pronounced when > 40 ng/ml was used as a cut-off point; this may support arguments that 25(OH)D levels need to reach a level of > 40 ng/ml to exert maximum immune effects.
Our position is that patients with CD should get enough sunshine or take enough vitamin D to have “natural” 25(OH)D levels (> 40 ng/ml). In many people, this will require 10,000 IU/day.