Vitamin D and IBD: What's the Link?

Now we're officially approaching freezing weather territory, there's one vitamin we're far more likely to be deficient in: Vitamin D.

We all know that we're much more likely to have lower levels of this key vitamin in the winter months (since we largely make it through sunlight's contact with our skin) but did you know that's it is closely linked to Inflammatory Bowel Disease too? In fact, monitoring our vitamin D levels can actually give us an indication of future disease activity too.

How Is Vitamin D linked to IBD?

It is important to remember that a significant proportion of the population is thought to be deficient in Vitamin D anyway - even more so if you are African American (deficiency is most prevalent in this group because pigmentation reduces the production of vitamin D in our skin). However, if you have IBD, then you are at a higher risk.

The Vitamin D council states there are many studies that show a link between IBD and Vitamin D. Whilst some people might think this is due to our social situation (we may tend to go outdoors less and prefer the comfort of our own homes during flare-ups) it's been shown in newly diagnosed IBD patients too, which makes us think that this could possibly even be used as a potential marker for testing the disease in the future?

But why is this the case? Well, vitamin D receptors are found in the digestive tract and the vitamin D we get from the sun and our diet binds to these receptors. With IBD patients, vitamin D can actually help reduce our inflammation - vitamin D can block TNF (yep, the same thing that Anti-TNF meds block!)

So, it may be that our bodies uses up more Vitamin D to do this, making us deficient. It could have something to do with the fact vitamin D is fat soluble, so our digestive system needs to be properly able to digest fat in order to absorb this vitamin properly. Either way, it certainly shows that vitamin D is closely linked to our digestive tract.

Have there been any studies about how vitamin D impacts our disease activity?

Yep, there's been a few with some interesting findings. The Vitamin D council provide an overview of these but here are some of the highlights (1)...

• A small experiment in the US showed that 67% of people went into remission when taking 5,000 IU of vitamin D a day (the dose started at 1000 IU and slowly increased) over a 24 week period.
•  A study in 2013 looked at the vitamin D levels of those with IBD. They found that those who had low levels were more likely to be hospitalized or have surgery

It's important to remember these are small studies, and the results will certainly not apply to everybody. Always speak to your doctor about your individual results rather than purely relying on those of others.

What should I do next?

It's important to make sure your doctor is regularly testing you for this, especially during the winter months. Regular testing will allow you to keep on top of things and ensure levels don't plummet. Since supplement doses vary, always make sure you talk to your doctor about the right dose for you. Foods like oily fish, mushrooms and egg yolks are also a good way of getting Vitamin D into your diet.