Taking vitamin D supplements won't improve painful symptoms of irritable bowel syndrome (IBS), British researchers report.
IBS is a chronic digestive disorder that can cause stomach cramps, bloating, diarrhea and constipation. Symptoms come and go for some people, but the condition can severely affect quality of life for many.
Previous research has suggested a link between low vitamin D levels and IBS.
"What our research shows is that supplementing vitamin D at a safe dose did not reduce the severity of IBS symptoms," said study author Liz Williams, a senior lecturer in human nutrition at the University of Sheffield.
She and her colleagues looked at 135 IBS patients, about half of whom used a vitamin D3 oral spray and the other half a placebo for 12 weeks. Even though vitamin D levels rose in participants taking the vitamin, there was no improvement in the severity of their IBS symptoms or their quality of life.
The study was published July 30 in the European Journal of Nutrition.
"There has been interest from researchers and from patient groups in the potential of high-dose vitamin D to alleviate symptoms of IBS, but there haven't been many properly controlled trials in this area," Williams said in a university news release.
While the supplements didn't help with IBS, she added that they did correct deficiencies in people whose vitamin D levels were low.
"This is important for other aspects such as bone and muscle health," Williams said.
Study co-author Bernard Corfe said for some people with severe IBS, low vitamin D levels may be due to changes in diet and lifestyle.
"Some may feel due to the severity of their symptoms that they limit their outdoor activities due to the anxiety their symptoms can cause, or alter their diet to avoid certain foods triggering their symptoms," said Corfe, a professor of human nutrition and health at Newcastle University.
Unfortunately, he added, these ways of coping can be harmful to health and well-being and reduce exposure to valuable sources of vitamin D.
"Given that vitamin D is essential for overall health and well-being, it is still important people with IBS get tested and treated and seek dietary advice so it does not impact on their long-term health," said Corfe, who is also an honorary fellow at the University of Sheffield.
The International Foundation for Gastrointestinal Disorders has more on IBS.
SOURCE: University of Sheffield, news release, July 29, 2021