The vitamin deficiency driving bowel problems

The “D” in vitamin D might as well stand for disease, because it’s connected to so many of them…

Autoimmune diseases, cancer, diabetes, heart disease are all linked to low vitamin D levels. You’ve probably read about the connection between vitamin D and some of these diseases in the news.

But there’s one disease that a lot people don’t realize is connected to vitamin D deficiency — irritable bowel syndrome (IBS).

Irritable bowel syndrome is the most common gastrointestinal disorder in the U.S. Chances are, you or someone you know has it. Although, it’s not a disease most of us like to talk about, since the symptoms are so embarrassing and unpleasant…

Gas. Stomach pain. Bloating. Diarrhea. Constipation. You get the picture.

Even though irritable bowel syndrome isn’t as serious as some of the other diseases tied to vitamin D deficiency, it makes you miserable and interferes with optimum health. So you want it to stop ASAP.

The problem is, like so many other diseases, there’s no final word on what causes it or how to treat it. But if you have IBS, the solution to your super cranky gut may be as simple as taking a vitamin D supplement…

Vitamin D and IBS

A recent study from the University of Sheffield in the UK found that people with irritable bowel syndrome are more likely to have vitamin D deficiency. They also found that vitamin D supplements can ease IBS symptoms.

University of Sheffield researchers reviewed seven existing studies on vitamin D and IBS. Four of the studies were observational studies and three were randomized controlled trials.

After looking at these studies, they concluded that people with irritable bowel syndrome were significantly more like to have low vitamin D levels than the general population. In fact, one of the studies they examined found that 82 percent of IBS sufferers had low vitamin D levels.

These researchers also concluded that vitamin D supplements reduced IBS symptoms like abdominal pain, bloating, diarrhea and constipation.

Considering most IBS sufferers struggle to find a successful treatment for their problem, this is big news. A cheap, highly available supplement could be the solution!

Slaying IBS with vitamin D

If you have irritable bowel syndrome, get your vitamin D levels tested pronto. If you’re vitamin D deficient, a supplement could help tame your symptoms.

But FYI… if you do decide to try a supplement to solve your IBS, you’ll probably need to take a high dosage. Official recommendations for vitamin D are currently set at 600 to 800 IU per day. But people with IBS seem to find success with doses much higher than that…

One study found that IBS sufferers who received 50,000 IU of vitamin D3 every two weeks for six months, substantially improved their symptoms. That averages out to about 3,500 IU of D3 per day. One published case study found that 3,000 IU of D3 per day did the trick for another IBS sufferer.

So shoot for something in the 3,000 to 3,500 IU per day range. Vitamin D toxicity doesn’t become a problem unless you’re taking 40,000 IU per day for a couple of months or longer. That means you’re well within the vitamin D safety zone — and hopefully the IBS-free zone too!


  1. Wang, et al. “Vitamin D and Chronic Diseases.” — Aging and Disease. May 2017; 8(3): 346–353.
  2. Irritable bowel syndrome — Mayo Clinic. Retrieved January 25, 2018.
  3. How Common is Irritable Bowel Syndrome (IBS) Really? — HealthCentral. Retrieved January 25, 2018.
  4. Vitamin D supplements could ease painful IBS symptoms — MedicalXpress. Retrieved January 25, 2018.
  5. E. Williams, et al. “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?” — European Journal of Clinical Nutrition, 2018.
  6. Large proportion of IBS patients are vitamin D deficient MedicalXpress. Retrieved January 25, 2018.
  7. Tazzyman, et al. “Vitamin D associates with improved quality of life in participants with irritable bowel syndrome: outcomes from a pilot trial.” — BMJ Open Gastroenterology, 2015.
  8. Low vitamin D levels associated with IBS — Medical News Today. Retrieved January 25, 2018.
  9. Study finds high dose vitamin D supplementation significantly improves irritable bowel syndrome — Vitamin D Council. Retrieved January 25, 2018.
  10. Am I getting too much vitamin D? — Vitamin D Council. Retrieved January 25, 2018.


Jenny Smiechowski

By Jenny Smiechowski

Jenny Smiechowski is a Chicago-based freelance writer who specializes in health, nutrition and the environment. Her work has appeared in online and print publications like Chicagoland Gardening magazine, Organic Lifestyle Magazine, BetterLife Magazine,, and