Vitamin D and the Gut Microbiota

Adam Hassan, BSc Microbiology and Immunology
Contributor

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In our most recent blog post, we discussed the importance of vitamins such as vitamin K2. Another crucial vitamin for healthy gut functions is vitamin D. Vitamin D represents a group of fat-soluble vitamins which are required for increasing intestinal absorption of calcium, iron, magnesium, phosphate, zinc (1). The most important in humans are vitamins D2 and D3. While this vitamin is often associated with the skin, it can be acquired from food intake just as well as from sunlight.

A study recently showed that a deficiency in vitamin D changes the intestinal microbiome and reduces vitamin B production in the gut. This means that there is a change in the type of bacteria living in our gut when we do not have enough vitamin D in our system (2). Furthermore, this lack of vitamin B leads to negative changes in our immune system. Our bodies suffer from increased inflammation and this can lead to autoimmunity – meaning our immune system is attacking healthy tissues and cells.

Finally, low levels of vitamin D have been linked with an increased risk of depression. Not only is this vitamin important for a healthy gut and a strong immune system, but also our mental health (3). It really is a molecule with several, diverse effects. Others include bone health, cancer, cardiovascular disease, cognition/dementia, pregnancy, and weight loss as well. 

Therefore, it is very important to maintain normal levels of vitamin D in our blood.

What can you do?

• Vitamin D is not naturally present in most foods. However, it is commonly added to in manufactured foods such as fruit juices, energy bars, cheese products, flour products, infant formulas, many breakfast cereals, and milk.
• Mushrooms are good dietary source of vitamin D2 while fish liver oils (cod liver old) are a good source of D3.
• Keep in mind that vitamin D content in typical foods is reduced variably by cooking, such as by boiling, frying or baking. Boiled, fried and baked foods retained 69–89% of original vitamin D (4). 

References
1. Holick, Michael F. "High Prevalence of Vitamin D Inadequacy and Implications for Health." Mayo Clinic. Mayo Clinic Proceedings, Mar. 2006. Web.
2. Gominak, S. C. "Vitamin D Deficiency Changes the Intestinal Microbiome Reducing B Vitamin Production in the Gut. The Resulting Lack of Pantothenic Acid Adversely Affects the Immune System, Producing a "pro-inflammatory" State Associated with Atherosclerosis and Autoimmunity." Medical Hypotheses. U.S. National Library of Medicine, Sept. 2016. Web.
3. Black, L. J., P. Jacoby, K. L. Allen, G. S. Trapp, P. H. Hart, S. M. Byrne, T. A. Mori, L. J. Beilin, and W. H. Oddy. "Low Vitamin D Levels Are Associated with Symptoms of Depression in Young Adult Males." The Australian and New Zealand Journal of Psychiatry. U.S. National Library of Medicine, May 2014. Web.
4. Jakobsen, Jette, and Pia Knuthsen. "Stability of Vitamin D in Foodstuffs during Cooking." Stability of Vitamin D in Foodstuffs during Cooking. Food Chemistry, 1 Apr. 2014. Web.

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