If you live in the Northern Hemisphere, you’re in the midst of winter and your body more than likely can’t make enough vitamin D from the sun because the sun is at too low an angle in the sky. Along those lines, isn’t it interesting a vitamin D deficiency is common in people with Inflammatory Bowel Disease (IBD)? Inflammatory bowel disease encompasses two independent but related entities: ulcerative colitis and Crohn's disease. In the Northeastern part of the United States, known for their lengthy, overcast winters, rates of ulcerative colitis and Crohn’s disease are highest, with rates in the Midwest and West not far behind.
The Link Between Vitamin D and Autoimmune Disease
Inflammatory bowel diseases are chronic, inflammatory, autoimmune disorders of the GI tract. It is now proven vitamin D is an important regulator of the immune system which may have implications for the development, severity and management of immune related disorders such as IBD. Particularly if someone with IBD has any malabsorption of dietary vitamin D, and/or has less exposure to the sun due to living in a climate suboptimal for vitamin D synthesis in the skin.
Ulcerative Colitis vs. Crohn’s Disease
The symptoms of these two diseases are quite similar, but the areas affected in the gastrointestinal tract (GI tract) are different.
Crohn’s most commonly affects the end of the small bowel (the ileum) and the beginning of the colon, also called the large intestine, but it may affect any part of the gastrointestinal tract, from the mouth to the anus. Ulcerative colitis is limited to the large intestine.
Crohn’s disease can also affect the entire thickness of the bowel wall, while ulcerative colitis only involves the innermost lining of the colon. Another difference is in Crohn’s disease, the inflammation of the intestine can “skip”— leaving normal areas in between patches of diseased intestine. This does not occur in ulcerative colitis. For more details about Crohn’s disease, visit my blog here.
Absorption of Dietary Vitamin D
Absorption of dietary vitamin D occurs in the upper small intestine, so if a person has had an intestinal resection due to some form of inflammatory bowel disease, they should be considered at risk of malabsorption of vitamin D, thus a low vitamin D status.
Vitamin D, IBD, and Bone Health
Vitamin D deficiency has been linked to bone loss among people with IBD, and bone loss is a problem for up to 50% of people with IBD. As a result, people with IBD are at risk of developing osteoporosis. To prevent bone disease, there are clear guidelines that recommend vitamin D supplementation for people with IBD, especially when undergoing steroid treatment. However, despite these recommendations, vitamin D deficiency is still common with IBD.
How Much Vitamin D?
The Vitamin D Council recommends adults with ulcerative colitis keep their serum vitamin D levels in the high-natural range, about 70-80 ng/ml. Your primary care physician can perform a simple blood test to determine current levels. The Vitamin D Council also advises children with ulcerative colitis should be given 2,000 IU per 25 pounds of body weight per day.
For Crohn’s disease, one study gave patients 2,000 IU per day and after 3 months, they had significantly less fatigue, increased muscle strength and an overall improvement in their quality of life.
Bottom Line: Vitamin D seems to play in integral part in overall well-being for those with some form of irritable bowel disease. Consult with your gastroenterologist and have your vitamin D levels checked.
In Health and Happiness,
Kelly Harrington, MS, RDN
Registered Dietitian Nutritionist for Healthy Goods
1. Andreassen H, Rungby J, Dahlerup JF, Mosekilde L. Inflammatory bowel disease and osteoporosis. Scand J Gastroenterol 1997;32:1247–55.
2. Andreassen H, Rix M, Brot C, Eskildsen P. Regulators of calcium homeostasis and bone mineral density in patients with Crohn's disease. Scand J Gastroenterol 1998;33:1087–93.
3. Margherita T Cantorna, Yan Zhu, Monica Froicu, and Anja Wittke. Vitamin D status, 1,25-dihydroxyvitamin D3, and the immune system. Am J Clin Nutr. December 2004; vol. 80, no. 6:1717S-1720S.
5. Holick MF. Vitamin D. In: Shils ME, Olson JA, Shike M, Ross CA, eds. Modern nutrition in health and disease. Baltimore: Williams & Wilkins, 1999:329–99.
6. Compston J, Creamer B. Plasma levels and intestinal absorption of 25-hydroxyvitamin D in patients with small bowel resection. Gut 1977;18:171–5.
7. Vitamin D Council: Inflammatory Bowel Disease.
8. Blanck S, Aberra F. Vitamin D deficiency is associated with ulcerative colitis disease activity. Dig Dis Sci. 2013 Jun;58(6):1698-702.
9. Vitamin D Council: Does vitamin D deficiency contribute to inflammatory bowel disease?
10. Walsh N. Vitamin D boosts quality of life in Crohn’s. MedPage Today. Mar 20, 2013.