Irritable Bowel Syndrome and Vitamin D
Irritable bowel syndrome (IBS) is a chronic disorder of the digestive tract primarily involving the large intestine. The symptoms of IBS typically include bloating, cramping, constipation, and diarrhea. It is quite common, estimated to affect approximately 10 percent of the population. The cause of IBS is not clear, but there are known triggers such as eating certain foods and experiencing stress. And now new research has uncovered a new possible risk factor for this disease as it showed a strong association between IBS and low levels of vitamin D.
The study, which was conducted at the University of Sheffield in the United Kingdom, found that the vast majority of individuals with irritable bowel syndrome may have low vitamin D levels.1 The subjects were 51 adults who all had a diagnosis of IBS. Blood samples were taken from each of them, and vitamin D levels were measured. The testing showed that an incredible 82 percent of the participants had inadequate levels of vitamin D.
All of the volunteers were asked to rate their quality of life, and those with low vitamin D were more likely to report theirs as poor compared to their peers with normal levels of the vitamin. After the initial blood work was complete, the trial continued for a 12-week period during which the subjects were divided randomly into three groups. One group was given sublingual vitamin D supplements, a second group received placebo pills, and a third group took vitamin D supplements and probiotics. This was a double-blind study, with neither the participants nor the scientists aware of which group was taking which pills.
But this portion of the research was considerably less informative than the blood screening, as no significant effects were found in any of the IBS patients even if they were taking vitamin D supplements. This is probably due to the flaws of the investigation more so than any lack of impact the vitamin might have. After all, there were only 51 volunteers included in the trial, which is way too small a sample size from which to draw any definitive conclusions. In addition, the length of the experiment was likely too short to produce enough of a change to result in a measurable outcome. It is an interesting twist, however, that although the findings about supplementation turned out to be totally inconclusive, the researchers received funding from a supplement manufacturer.
The more important aspect of this study that we should be focusing upon instead is the connection between low levels of vitamin D and the presence of irritable bowel syndrome. While the research was not designed to prove cause and effect, it certainly shows an overwhelming association. And IBS is hardly the first illness to which low vitamin D has been linked. A 2010 study at the Johns Hopkins University School of Medicine in Baltimore found a strong correlation between Type 2 diabetes and lack of vitamin D.2 And a 2009 study at the University of Oxford in the United Kingdom showed that a lack of vitamin D triggers a gene response that can lead to multiple sclerosis.3
In other words, it is essential to make sure you are getting enough vitamin D. Adequate levels of this vitamin may help prevent the development of IBS and the other serious conditions it is associated with, and it also may have a positive effect on symptoms if you already do have one of these disorders.
To obtain a sufficient intake of vitamin D, your best bet is spending a little time in the sunshine. Unfortunately, the components of sunblock that help us avoid sunburns also hamper our bodies' ability to create the necessary amounts of vitamin D. So if you aren't an outdoorsy type or use your SPF 50 religiously, it's possible you may end up with a vitamin D deficiency. All but the most sun-sensitive of us can safely be outside for 15 unprotected minutes a day, which is enough exposure to get the sunlight we need for vitamin D production. (Note: the sun needs to be at 50 degrees in the sky for sun bathing; but keep in mind that at 45 degrees latitude--which runs through the northern US--the sun rises and sets at 45 degrees, which means that it's almost always 50% or higher during the day.) And taking supplements can also help ensure you get enough vitamin D. Choose a supplement with 1,000 to 2,000 IU of vitamin D3 to take daily.
- 1. Tazzyman, Simon; et al. "Vitamin D associates with improved quality of life in participants with irritable bowel syndrome: outcomes from a pilot trial." BMJ Open Gastroenterology. 21 December 2015. Accessed 26 December 2015. http://bmjopengastro.bmj.com/doi/full/10.1136/bmjgast-2015-000052.
- 2. Krug, Esther; et al. "Poor control of diabetes may be linked to low vitamin D." Endocrine Society. June 2010. Accessed 27 December 2015. https://www.endocrine.org/news-room/press-release-archives/2010/poorcontrolofdiabetesmaybelinkedtolowvitamind.
- 3. Ramagopalan, Sreeram V.; et al. "Expression of the Multiple Sclerosis-Associated MHC Class II Allele HLA-DRB1*1501 Is Regulated by Vitamin D." PLOS Genetics. 6 February 2009. Accessed 27 December 2015. http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1000369.