Vitamin D may help boost immune function and reduce inflammation, which could benefit people living with ulcerative colitis. However, more research is needed to fully understand the link.

Ulcerative colitis is a type of inflammatory bowel disease (IBD) that affects the gastrointestinal (GI) tract.

Vitamin D is a fat-soluble vitamin primarily knownTrusted Source for its beneficial effects on bone, brain, and immune health. Some research suggests it may also benefit people with ulcerative colitis.

Keep reading to learn more about how vitamin D may help support the management of ulcerative colitis symptoms.

Tan capsule supplements against a tan background.Share on Pinterest
Sophia Hsin/Stocksy United Sophia Hsin/Stocksy United

Some research suggests that people with ulcerative colitis are more likelyTrusted Source to have low vitamin D levels due to several factors, such as malabsorption and inadequate dietary intake because of IBD symptoms.

Lower vitamin D levels have been linkedTrusted Source to a higher risk of disease development, severity, and complications like pancolitis.

As such, some researchers believeTrusted Source that vitamin D supplementation may be an effective, low cost treatment for ulcerative colitis.

However, it’s important to note that not all researchers agree.

For instance, the authors of a 2023 research reviewTrusted Source concluded that not enough high quality studies exist to support the use of vitamin D for ulcerative colitis.

Here’s how vitamin D may affect ulcerative colitis.

It may improve intestinal barrier function

People with IBD are more likelyTrusted Source to have increased intestinal barrier permeability. This means your gut’s lining is compromised, allowing food and friendly gut bacteria to reach intestinal tissue.

This increases your immune system’s exposure to gut microbiota, which may lead to a heightened and abnormal immune response associated with inflammation and increased disease severity.

Vitamin D may help maintain intestinal barrier integrity by regulating proteins that could revert gaps in intestinal tissues.

It may improve gut microbiota

Vitamin D may help improve and rebalance the gut microbiota, which may help reduce GI inflammation.

The microbiota of people with ulcerative colitis is more likelyTrusted Source to vary over time.

Vitamin D deficiency may also alter the microbial balance. For instance, it may increase the concentration of certain bacteria that could cause colon inflammation and reduce bacteria that may help relieve inflammation.

It may reduce inflammatory immune responses

Research suggests that vitamin D may help inhibit multiple pro-inflammatory pathways.

It may helpTrusted Source reduce oxidative stress by regulating oxidative stress-reducing proteins, leading to reduced inflammation.

Vitamin D supplementation may also have positive effects on T cells, a type of white blood cell that helps eliminate disease-causing microorganisms.

According to a 2016 research reviewTrusted Source, T cells with low vitamin D levels promote higher concentrations of pro-inflammatory markers, grow more rapidly, and induce more severe colitis. In contrast, animal studies show that treating T cells with vitamin D slowed their growth, reducing inflammation.

It may reduce the risk of colon cancer

Inflammation plays a fundamental roleTrusted Source in the development of colon cancer.

People with IBD have an increased risk of developing colitis-associated colon cancer, especiallyTrusted Source if they have vitamin D deficiency or if their inflammation is not well-managed.

Some animal studiesTrusted Source suggest higher vitamin D levels may help reduce the risk of colon cancer, but more research in humans is needed to fully understand the link between vitamin D, ulcerative colitis, and colon cancer.

Low vitamin D levels are linkedTrusted Source with increased disease severity and a higher risk of relapse. However, evidence on whether vitamin D supplementation benefits ulcerative colitis is mixed.

Some studies have foundTrusted Source that vitamin D supplementation may help reduce inflammation, disease activity, and symptoms, as well as increase remission rates.

However, vitamin D supplementation for IBD is challengingTrusted Source because impaired nutrient absorption requires higher doses, which may lead to vitamin D toxicity.

As such, more research on vitamin D supplementation for ulcerative colitis is needed.

According to the Food and Drug Administration (FDA), the recommended daily value (DV) of vitamin D is 20 mcgTrusted Source, or 800 International Units (IU).

However, you may need a higher dose if you have ulcerative colitis and have a vitamin D deficiency.

Research suggests that daily dosages of 2,000 IUTrusted Source may help improve symptoms and quality of life and are safe for people with mild deficiency.

Once sufficient vitamin D levels are reached, however, there’s no consensus on how much vitamin D is necessary to maintain them. Some people suggest that taking 1,000 IUTrusted Source per day is sufficient, but others note that people with severe deficiency require up to 4,000 IUTrusted Source daily.

As such, it’s best to speak with a healthcare professional about how much vitamin D you should be consuming daily.

Vitamin D supplementation is safe for most people, but some possible side effects may includeTrusted Source:

A note on choosing high quality supplements

While research suggests there are health benefits to taking vitamin D supplements, the FDA doesn’t monitor or regulate the quality of supplements in the same way that it regulates clinical medications.

Consider talking with a healthcare professional before using supplements, and be sure to research the quality of a brand’s products.

A healthcare professional can help develop the best treatment plan to help you manage ulcerative colitis and vitamin D deficiency. This may include a combination of the following:

Learn more about natural remedies and eating a well-balanced diet for ulcerative colitis.

Does vitamin D help with gut inflammation?

Some researchTrusted Source suggests that vitamin D supplementation may help reduce gut inflammation, but more research is needed to fully understand the link between vitamin D and gut health.

Can low vitamin D cause bowel problems?

Some researchTrusted Source suggests that low vitamin D levels may increase the progression of IBD, which could exacerbate bowel symptoms like diarrhea, bloody stools, and abdominal pain.

Vitamin D is a fat-soluble vitamin that may play a key role in the progression and management of ulcerative colitis.

Some research suggests that vitamin D may benefit gut health by improving immune response and reducing inflammation.

However, it’s important to remember that evidence on whether vitamin D supplementation is beneficial is mixed, and more research is needed. An adequate and safe dose is yet to be determined.

Consider speaking with a healthcare professional before trying vitamin D to manage your symptoms.