In a recent study published in the American Journal of Gastroenterology it was noted that many IBD patients had lowered levels of vitamin D (1). In fact according to the Crohn's and Colitis Foundation of America up to 68% of Crohn's patients have a vitamin D deficiency.
It is possible that there are several factors contributing to this problem.
One cause of vitamin D deficiency could be the lack of dietary sources due to restrictive diets implemented to lessen IBD symptoms. Another cause for low levels of vitamin D could be issues with absorption. This is especially true for patients who may have had GI surgeries that removed portions of the intestine where vitamin D is absorbed.
Active inflammation in the small intestine or the use of corticosteroids can decrease the body's ability to absorb vitamin D (along with other vitamins and minerals). It may also be less easily absorbed than water soluble vitamins due to fat malabsorption. Any one of these things can contribute to altered vitamin D status.
Why is vitamin D so important? There are several reasons why maintaining an optimal level of vitamin D is crucial. Two of the most notable are its role in maintaining normal bone density and immune system function.
Vitamin D is essential in the absorption and mobilization of calcium and phosphate, both of which are required to maintain proper bone density. This corroborates the findings in the American Journal of Gastroenterology study which noted that there may be some correlation between lowered serum vitamin D status and risk of fracture in IBD patients (See Commentary).
There is also promising research on the role of vitamin D in autoimmune diseases. It has already been linked to arthritis and multiple sclerosis and there is a lot of discussion on its role in the treatment of IBD. Some research has indicated that vitamin D supplementation can also decrease the need for anti-inflammatory medications in IBD patients (For additional info click, here).
It is not clear as to whether vitamin D supplementation is necessary for IBD patients with normal serum levels. What is clear is that vitamin D can be toxic in high levels and it plays an important role in serum calcium levels. For these reasons supplementation should be discussed and supervised by your physician.
Please check back for Part II on this topic. I will cover the role that calcium plays in bone density and good dietary sources of both vitamin D and calcium.
1. Am J Gastroenterol 2008;103:1451-1459
For more information on vitamin and mineral loss in people with IBD see Jen's previous posts:
Published On: August 04, 2008