Quick version
A study published in BMJ Open Gastroenterology in 2015 found that over 80% of 51 participants with IBS had insufficient levels of vitamin D, and that their quality of life was strongly linked to their vitamin D status. Another study, published in the European Journal of Clinical Nutrition in 2017, showed that IBS symptoms and quality of life improved in participants who received vitamin D supplements.
How can vitamin D affect IBS?
Vitamin D plays an important role in the immune system and can affect inflammation levels in the body. Because IBS is often linked to low-grade inflammation and an oversensitive gut flora, researchers have investigated whether vitamin D deficiency may contribute to symptoms such as bloating, diarrhea, and constipation.
Research also indicates that vitamin D can directly affect the gut microbiome. A healthy gut flora is crucial for proper digestion, and some studies suggest that vitamin D can support the growth of beneficial bacteria while reducing inflammatory processes in the body.
Do IBS patients need vitamin D supplements?
Although research does not yet provide a clear answer, people with IBS may benefit from testing their vitamin D levels, especially during the winter months when deficiency is more common. If levels are low, supplementation may be considered to improve both overall health and gastrointestinal symptoms.
While more studies are needed to confirm the link between vitamin D and IBS, there are promising results that suggest that vitamin D deficiency may play a role in the symptom picture.