Taking a Closer Look: Vitamin D Deficiency and Irritable Bowel Syndrome

Taking a Closer Look: Vitamin D Deficiency and Irritable Bowel Syndrome

Published on Friday, May 13, 2022 by Emily Hamm

Did you know?? There is SO MUCH on-going research surrounding vitamin D and its vital role in human health?

First off, let’s discuss what Vitamin D is. As a fat soluble vitamin it is found naturally in a few foods and added to others. Our bodies also have the ability to create vitamin D through UV light which triggers vitamin D synthesis in our skin. You can also get vitamin D through supplementation.

Vitamin D is responsible for the following:

  •         bone health
  •         reduction of inflammation in the body
  •         immune function
  •         cell growth and destruction
  •         neuromuscular function
  •         glucose metabolism


Our gut health is fundamental in immune function and reduction of inflammation in the body. 

If you suffer from gastric motility disorders (i.e. irritable bowel syndrome, chronic functional constipation, and intestinal pseudo-obstruction) then you may suffer from the inability to digest and absorb micronutrients such as vitamin D.

A study conducted by Linsalata et al. found a close link between vitamin D status and altered intestinal barrier function in IBS-diarrhea patients who were following a Low-FODMAP diet long-term. The authors concluded that subjects who had a lower vitamin D level showed significantly worse symptoms and had altered small intestinal permeability versus subjects with normal vitamin D levels. 

Once these subjects in the study started a Low-FODMAP diet and followed it for 12 weeks, vitamin D levels increased suggesting that diet intervention for management of IBS-D significantly improved gut permeability and restored vitamin D levels.

How do you know if you have enough vitamin D? 

Ask your primary care provider to check your vitamin D levels. Insurance will typically cover this laboratory test with routine blood work. If your vitamin D is low (less than 30 nmol/L) then you might benefit from vitamin D supplementation. Your provider will determine if you need prescription strength vitamin D or if supplementing with a general over-the-counter vitamin will do the trick.

You can also increase your vitamin D levels by doing the following:

  • Spend 30 minutes outdoors each day – natural sunlight can help us produce our own vitamin D. Just be cautious to not get too much sun exposure leading to skin damage
  • Eat and drink foods rich in vitamin D
    o   Fatty fish (salmon, cod, herring, sardines, canned tuna)
    o   Beef or calf liver
    o   Eggs
    o   Fortified milk/dairy products
    o   Fortified tofu
    o   Shiitake mushrooms
    o   Fortified orange juice
    o   Fortified cereals

    **Keep in mind if certain foods bother or exacerbate your IBS, then you will want to avoid them. Talk with a Registered Dietitian about trialing the Low-FODMAP diet to help identify foods that trigger your symptoms**

    Linsalata M, Riezzo G, Orlando A, D'Attoma B, Prospero L, Tutino V, Notarnicola M, Russo F. The Relationship between Low Serum Vitamin D Levels and Altered Intestinal Barrier Function in Patients with IBS Diarrhoea Undergoing a Long-Term Low-FODMAP Diet: Novel Observations from a Clinical Trial. Nutrients. 2021 Mar 21;13(3):1011. doi: 10.3390/nu13031011. PMID: 33801020; PMCID: PMC8004066.

    Take a Look at These Options to Add Some Vitamin D into Your Meals & Snacks:

    Gluten Free Cereal with Whole Grain Oats (20 oz)

    Dried Shiitake Mushrooms (16 oz)

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