Might vitamin D therapy help individuals with Crohn's disease?

Crohn’s disease is what is known as an ‘inflammatory bowel disorder’ (the other major inflammatory bowel disorder is ulcerative colitis). The inflammation in Crohn’s can affect any part of the gut (from the lips to the anus), and common symptoms include abdominal pain, bloating and diarrhoea which can be bloody. The conventional approach to this condition is to treat with anit-inflammatory drugs and as well as those that the suppress the immune system including steroids. Sometimes, Crohn’s disease can lead to narrowing (stricture) in the gut. It’s not uncommon for sufferers to undergo surgery to remove narrowed or badly affects parts of the gut.

Back in January I became aware of research linking Crohn’s disease with vitamin D deficiency [1]. A group of scientists at McGill University and the Universite de Montreal (both in Montreal). Vitamin D was found to act directly on a gene (the beta defensin 2 gene), which is implicated in the development of Crohn’s disease. If you’d like more details about this article, you can read about it here.

I didn’t write about this research at the time, partly because I tend not to report much on research done in the lab looking at genetic or biochemical mechanisms. While this research can be interesting, it’s generally not as useful or relevant as ‘clinical’ studies in which treatments or approaches are tested on live beings (preferably humans, if it’s human health we’re interested in). Well, now someone has tested vitamin D supplementation in Crohn’s sufferers, and the results suggest that this treatment has at least some promise in the treatment of this condition.

In this study, about 100 Crohn’s sufferers were treated with either 1200 IU of vitamin D3 daily, or placebo, for a year [2]. Relapse rate (recurrence of active disease) was 13 per cent in those taking vitamin D, compared to 29 per cent in the placebo group. This result, however, not statistically significant.

The vitamin D dose did lead to a significant increase in vitamin D levels in the body – initial average levels were 69 nmol/l (28 ng.ml) which rose to an average of 96 nmol/l (38 ng/ml) after three months of treatment. Some might argue that these levels are still lower than ‘optimal’. Also, perhaps the study did not go on long enough to see the full benefit. Another limiting factor was the study’s size – relatively small numbers mean that we generally need to see very big differences in treatment response for results to be ‘statistically significant’.

The authors of this study have called for larger studies to be done, and I think this is a good idea, given how devastating a disease Crohn’s can be, and the fact that vitamin D might turn out to be a simple, safe (not to mention cheap) approach to keeping the condition at bay.

It is possible, of course, that vitamin D turns out not to be beneficial for Crohn’s. However, there for a long time has been mounting evidence that optimising vitamin D levels can improve health and wellbeing, and higher vitamin D levels are associated with a reduced risk of many chronic conditions including cancer, heart disease and diabetes.

References:

1. Wang TT, et al. Direct and indirect induction by 1,25-dihydroxyvitamin D3 of theNOD2/CARD15-beta defensin 2 innate immune pathway defective in Crohn’s disease. The Journal of Biological Chemistry. 2010;285(4):2227-31

2. Jorgensen SP, et al. Clinical trial: vitamin D3 treatment in Crohn’s disease – a randomised double-blind placebo-controlled study. Aliment Pharmacol Ther 2010 May 11 [Epub ahead of print]