Low vitamin-D status has been linked to inflammatory bowel disease and increased risk of colorectal cancer. Some early reports also suggest a link with irritable bowel syndrome (IBS) symptoms.
In a paper in the European Journal of Clinical Nutrition (online, 25 January 2018), researchers reviewed the current state of the literature on the role of vitamin D supplementation in IBS.
The team found that there are limited data available. Only three randomised controlled trials have been reported — two of which found a beneficial effect of vitamin D on IBS symptoms in people with low vitamin-D status; however, these were of poor quality. All four observational studies identified found that people with IBS have a high likelihood of vitamin D deficiency.
The team said the literature indicates a potential role for vitamin D in IBS symptom severity, but larger randomised controlled trials are needed before supplementation can be considered a therapeutic option for the condition.
 Williams C, Williams E & Corfe B. Vitamin D status in irritable bowel syndrome and the impact of supplementation on symptoms: what do we know and what do we need to know? Eur J Clin Nutr 2018. doi:10.1038/s41430-017-0064-z