A randomized controlled study published in BMJ Open Gastroenterology found that vitamin D supplementation was associated with improved quality of life in participants with IBS.
The researchers presented evidence of high vitamin D deficiency in populations with IBS and revealed that these IBS sufferers experienced poorer quality of lives compared to their counterparts who had replete vitamin D levels.
Depression is a common comorbid ailment in IBS, and numerous studies have reported that vitamin D levels are correlated with depression. Consequently, it's not surprising that reported quality of life in IBS patients is influenced by vitamin D status.
The exact mechanism through which vitamin D improves depression is not yet fully understood. However, scientists have confirmed that the vitamin D receptor (VDR) is expressed throughout the nervous system and has been implicated in neurological development. VDR is also expressed in the digestive tract and regulates both the epithelial barrier function and bowel inflammation. This suggests that vitamin D deficiency may directly influence bowel function and, as a result, IBS symptoms. The study, though small, yielded very strong results, suggesting that patients with IBS should add vitamin D supplementation to their treatment regimens.
Although the research is still in its infancy, the findings indicate that vitamin D therapy correlates with improved abdominal pain and distention, flatulence, rumbling, and overall gastrointestinal symptoms. The study concluded that 50,000 IU of vitamin D3 taken bimonthly for six months improved IBS symptoms.
People who are older, dark skinned, obese, use sunscreen, or live in regions with limited sunshine, such as those that are far from the equator, for either part or all of the year are at the greatest risk of vitamin D deficiency. Most Americans get vitamin D through sunshine, fortified milk, and fortified margarine. The only significant, natural sources of vitamin D in foods are from animal sources (fatty fish and eggs from chickens fed vitamin D). A vegan diet contains little, if any, vitamin D, unless it's obtained via fortified foods or supplements. With rare exception, the vitamin D3 in supplements is derived from animals, usually from fish oil or the lanolin found in sheep's wool. Vitamin D2, also called ergocalciferol, is obtained from yeast or from mushrooms exposed to commercial ultraviolet light or direct sunlight and is vegan.
There has been a long-running debate in the scientific community about whether vitamin D3 supplements are more effective than vitamin D2 supplements. Although several recent studies indicate that both forms of vitamin D are equally effective, the general consenus has been that D3 is more effective at raising and maintaining vitamin D levels, especially in large doses. Also, because vitamin D is a fat-soluble vitamin, taking vitamin D supplements with foods that contain fat might help to increase absorption.
Fortunately for vegans with IBS, Vitashine, a company based in the UK, has created the first (and currently only) vegan form of vitamin D3. It's sold in the US under a variety of different brand names and manufacturers, but they all will state "Vitashine" on the product label.
Could you benefit from vitamin D supplementation? Most people, even those without IBS, are low in vitamin D, so supplementation in recommended amounts (per the dosages listed on the product) couldn't hurt and may only help. But if you suspect you might have a high deficiency that's exacerbating your IBS symptoms, including depression, seasonal affect disorder, or other health issues, contact your doctor to get your levels tested. If a high amount of supplementation is recommended, your doctor should supervise your progress and dosage. This is important, because vitamin D can interact with certain medications and supplements, too much vitamin D can have side effects (including constipation), some of which may be serious.