Irritable Bowel Syndrome: Vitamin D Offers No Benefits for the Treatment of IBS

So far the fundamental causes of irritable bowel syndrome (IBS) are still unknown, and there is no specific way to prevent or treat the symptoms. Several studies have found a common vitamin D deficiency in patients with IBS. But the causal link has not yet been established, and the benefits of vitamin D supplementation for IBS patients have just now been evaluated by a team of British researchers.

Digestive System

Irritable bowel syndrome (IBS) is a disorder of intestinal function. Although the symptoms are not severe, they are unpleasant because of their chronicity and the discomfort they cause (pain, bloating, constipation, diarrhea). 10% to 15% of the US population is affected by this syndrome, which affects women more frequently than men and seriously compromises the quality of life of those affected.

Currently, the pathogenesis of irritable bowel syndrome is poorly understood. Researchers have considered various mechanisms (gastrointestinal motility disorders, epithelial barrier alteration, flora imbalance, visceral hypersensitivity, Biofilm, immune factors, and much more). In addition, recent studies suggest that vitamin D deficiency is common in populations with IBS. An inverse relationship between serum vitamin D levels and symptom severity is suggested.

Is Vitamin D a good candidate for relieving symptoms of irritable bowel syndrome?

Vitamin D plays an important role in the health of bone and muscle tissue and in strengthening the immune system. It is metabolized in the liver and kidneys into an active form and is involved in regulating calcium and phosphate absorption in the digestive system. In addition, the small and large intestines express high levels of vitamin D receptors. It promotes intestinal epithelial barrier function and defense against pathogens (by stimulating the maturation of monocytes into macrophages). It also helps maintain the stability of mast cells, whose activity is increased in visceral hypersensitivity. In addition, there is growing evidence that vitamin D influences the microbial balance of the gut by promoting microbiota diversity and bacterial production of butyrate (a short-chain fatty acid with anti-inflammatory effects).

What effect does vitamin D supplementation have on irritable bowel syndrome?

A randomized study has just been published in the European Journal of Nutrition. The study was conducted by a team from Sheffield (UK) in winter 2018 and 2019 and included 135 participants with IBS, of whom a group received vitamin D supplementation.

There was no difference in symptom severity and quality-of-life scores in the supplemented group and the control group. No association was found between changes in vitamin D levels and symptoms. In light of these findings and although causality has not been demonstrated, the authors suggest that individuals with irritable bowel syndrome should still be screened (vitamin D levels) and supplemented if necessary.