Vitamin D deficiency and inflammatory bowel disease (IBD)

Vitamin D helps to regulate the amount of calcium and phosphate in the body and is essential for healthy bones. It also plays a role in reducing inflammation and is important for good general health and growth.

There are many studies which have shown a link between people with inflammatory bowel disease (IBD) having low levels of vitamin D. It is one of the most common vitamin deficiencies seen in people with Crohn’s disease. A five-year study published in 2016 found that low levels of vitamin D in people with IBD is associated with high disease severity1. It highlights the importance of monitoring and treatment for people with IBD.

Vitamin D is essential for calcium to be absorbed into the body - meaning people with a lack of vitamin D often have a lack of calcium.

A small lack of vitamin D may not cause symptoms but can cause:

  • Tiredness
  • General aches and pains

A severe lack of vitamin D can result in:

  • Bone deformities (such as rickets) in children
  • Bone pain and tenderness in adults (osteomalacia)

People with IBD are more prone to osteoporosis and bone disease, in part, is attributed to a lack of vitamin D.

A vitamin D deficiency can be diagnosed with a blood test by your doctor. Some companies provide private home testing - such as this one* based in the UK

Why might people with IBD be deficient in vitamin D?

There are a few different thoughts as to why people with IBD may have less vitamin D.

These include:

  • Due to their symptoms they may be more likely to stay inside, near a toilet or resting, and therefore don’t get as much access to sunlight (and sunlight increases your vitamin D levels)
  • More people with IBD live in northern areas - where there is less sunlight. Therefore, the whole population is likely to have less vitamin D - whether they have IBD or not!
  • Vitamin D is a fat soluble vitamin. People with active inflammation in their small intestine poorly absorb fat, meaning there is less fat for vitamin D to be absorbed in


How can I get more vitamin D?

Vitamin D is made under our skin in reaction to sunlight so increasing exposure to sunlight can increase your vitamin D levels. However, make sure you do this safely. In northern areas (including much of Europe) there is not thought to be enough sunlight during the winter months to get the sun exposure needed. It is therefore important to get vitamin from other sources, such as your diet or through supplements.

It is also found naturally in a small number of foods including:

  • Oily fish such as salmon, sardines and mackerel
  • Eggs

There are also some foods which are fortified with vitamin D.

Vitamin D supplements are also available to buy* or you can get a vitamin D spray*. If you take supplements make sure you do not exceed the recommended dose.

A vitamin D injection is also offered to some people in some parts of the world.

*Please note this is an affiliate link which means if you buy from the company we may receive a commission. You will pay the same price as you normally would and any money earned will be used to support IBDrelief's work.


1. Association of Vitamin D Level With Clinical Status in Inflammatory Bowel Disease: A 5-Year Longitudinal Study. Toufic A Kabbani, Ioannis E Koutroubakis, Robert E Schoen, Claudia Ramos-Rivers, Nilesh Shah, Jason Swoger, Miguel Regueiro, Arthur Barrie,Marc Schwartz, Jana G Hashash, Leonard Baidoo, Michael A Dunn and David G Binion. The American Journal of Gastroenterology 111, 712-719 (May 2016)

Products you may like



Find this article useful?

Why not sign up to our mailing list and receive regular articles and tips about IBD to your inbox?