Leaky Gut and vitamins

Content
1. What is leaky gut?
2. Nutrition for Leaky Gut
3. What are vitamins?
4. Vitamins and leaky gut
4.1 Vitamin D and leaky gut
4.2 Vitamin A and leaky gut
4.3 Vitamin C and leaky gut
4.4 Vitamin E and leaky gut
4.5 Vitamin B12 and leaky gut
5. Omega-3 and leaky gut
6. Summary

1. What is leaky gut?

The leaky gut syndrome, or simply leaky gut, refers to an increased permeability of the intestinal lining (increased intestinal permeability). This heightened permeability and the resulting impaired barrier function of the gut are often associated with immune system activation and a disrupted microbiome or disturbed gut flora. Symptoms of leaky gut include issues such as digestive problems, fatigue, headaches, muscle pain, difficulty concentrating (“brain fog”), skin problems, joint pain, and systemic inflammation.

2. Nutrition for Leaky Gut

Diet plays a crucial role in the development of leaky gut. Therefore, it is important to follow an appropriate diet when dealing with existing leaky gut. In particular, foods that support the healing of the intestinal barrier and have anti-inflammatory effects should be consumed. At the same time, foods that could irritate the gut, especially its mucosal lining, should be avoided.

3. What are vitamins?

Vitamins are essential nutrients that the body needs to maintain various biological processes and functions. They are crucial for health and well-being, as they perform a wide range of tasks such as supporting the immune system, promoting cell regeneration, aiding metabolism, and protecting against free radicals.
Vitamins come in different forms, each serving specific functions, and are found in a variety of foods, including fruits, vegetables, whole grains, meat, and dairy products. A deficiency in certain vitamins can lead to health problems, which is why a balanced diet is so important.
Vitamins are divided into two main categories: water-soluble and fat-soluble. Water-soluble vitamins include, for example, vitamin C and the B vitamins (e.g., B1, B2, B6, B12). Fat-soluble vitamins such as vitamin A, D, E, and K require fat to be absorbed and stored by the body. Both groups are essential for health, fulfilling different roles and being processed differently within the body.

4. Vitamins and leaky gut

Vitamins are not only essential nutrients for overall health, but they also play a crucial role in supporting gut health. Particularly in the treatment and prevention of leaky gut, certain vitamins can help strengthen the integrity of the intestinal barrier and reduce inflammation. A permeable gut, also known as leaky gut, can result from a variety of factors such as poor diet, chronic stress, or an imbalance in the gut microbiota. In this context, vitamins are vital for stabilizing gut function and enhancing its protective barrier.
The following sections will take a closer look at specific vitamins that play a key role in the fight against leaky gut.

4.1 Vitamin D and leaky gut

Vitamin D is much more than just a nutrient that strengthens the immune system — it is also a crucial factor in maintaining a healthy gut barrier. The body can produce vitamin D itself through exposure of the skin to sunlight; however, the amount produced varies depending on the season and geographic location. Especially during the winter months or in regions with limited sunlight, it can be difficult to produce sufficient amounts of vitamin D. For this reason, it is important to also obtain vitamin D through diet or supplementation.
An optimal vitamin D level not only helps to strengthen the immune system but also promotes the stability of the gut barrier by supporting the production of proteins that reinforce the cell junctions in the gut — the so-called tight junctions (1,2,5). These tight cell connections are crucial for maintaining the integrity of the intestinal wall and preventing harmful substances from entering the bloodstream. In addition, vitamin D is known for its anti-inflammatory properties (3,5), which can be beneficial in treating intestinal inflammation and reducing gut permeability.

4.2 Vitamin A and leaky gut

Vitamin A is another fat-soluble vitamin that plays a vital role in a wide range of physiological processes in the body. In addition to its well-known importance for eye health and the immune system, vitamin A is also responsible for the growth and development of cells. A particularly noteworthy aspect of vitamin A is its ability to promote the health of the skin and mucous membranes by supporting their regeneration and repair. This is especially important for maintaining a stable intestinal mucosa.
An intact intestinal lining is essential to prevent the passage of toxins, bacteria, and other harmful substances. Therefore, vitamin A is also attributed with a strengthening effect on the intestinal mucosa (4,5).

4.3 Vitamin C and leaky gut

Vitamin C is a water-soluble vitamin that acts as a powerful antioxidant and plays a central role in supporting the immune system and tissue repair. In the context of leaky gut, vitamin C is particularly important as it reduces oxidative damage (6), which can weaken the intestinal barrier. Vitamin C can also positively influence the composition of the gut microbiota (7).

4.4 Vitamin E and leaky gut

Vitamin E is a fat-soluble vitamin and antioxidant known for protecting cell membranes from oxidative stress and regulating inflammatory processes in the body (8). In the context of leaky gut, vitamin E plays an important role as oxidative stress and chronic inflammation are key factors in the damage to the intestinal barrier. Vitamin E can help maintain the integrity of the intestinal wall (7) and positively influence the composition of the gut microbiota (7). Therefore, vitamin E plays a crucial role in the prevention of leaky gut.

4.5 Vitamin B12 and leaky gut

Vitamin B12 is a water-soluble vitamin required for many vital body functions. In relation to leaky gut, vitamin B12 plays a supportive role as it is involved in cell division and tissue regeneration (9). These processes are also important for the repair of a damaged intestinal lining. A deficiency in vitamin B12 can impair cell renewal, making it more difficult to regenerate the intestinal barrier. Therefore, adequate levels of vitamin B12 are essential for supporting the intestinal mucosa and maintaining a healthy barrier function.

5. Omega-3 and leaky gut

Although omega-3 fatty acids are not vitamins, they play a similarly essential role in health, which is why they are briefly mentioned here. Omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), are known for their strong anti-inflammatory properties (10). Omega-3 fatty acids can help improve the integrity of the intestinal wall (11) by regulating inflammatory processes (10). Therefore, adequate intake of omega-3 can be an important addition to a vitamin-rich diet to promote gut health and prevent leaky gut.

6. Summary

Adequate intake of essential vitamins, combined with a healthy diet and lifestyle, can help reduce the risk of leaky gut and support gut health. Whether an individual is getting sufficient amounts of these vitamins can be determined by a doctor. A nutritionist can help increase the intake of these vitamins through dietary adjustments.

References

1. Zhang YG, Wu S, Sun J. Vitamin D, Vitamin D Receptor, and Tissue Barriers. Tissue Barriers. 2013 Jan 1;1(1):e23118. doi: 10.4161/tisb.23118. PMID: 24358453; PMCID: PMC3865708.
2. Michielan A, D’Incà R. Intestinal Permeability in Inflammatory Bowel Disease: Pathogenesis, Clinical Evaluation, and Therapy of Leaky Gut. Mediators Inflamm. 2015;2015:628157. doi: 10.1155/2015/628157. Epub 2015 Oct 25. PMID: 26582965; PMCID: PMC4637104.
3. Li YC, Chen Y, Du J. Critical roles of intestinal epithelial vitamin D receptor signaling in controlling gut mucosal inflammation. J Steroid Biochem Mol Biol. 2015 Apr;148:179-83. doi: 10.1016/j.jsbmb.2015.01.011. Epub 2015 Jan 17. PMID: 25603468; PMCID: PMC4361385.
4. Abdelhamid L, Luo XM. Retinoic Acid, Leaky Gut, and Autoimmune Diseases. Nutrients. 2018 Aug 3;10(8):1016. doi: 10.3390/nu10081016. PMID: 30081517; PMCID: PMC6115935.
5. Cantorna MT, Snyder L, Arora J. Vitamin A and vitamin D regulate the microbial complexity, barrier function, and the mucosal immune responses to ensure intestinal homeostasis. Crit Rev Biochem Mol Biol. 2019 Apr;54(2):184-192. doi: 10.1080/10409238.2019.1611734. Epub 2019 May 14. PMID: 31084433; PMCID: PMC6629036.
6. Padayatty SJ, Katz A, Wang Y, Eck P, Kwon O, Lee JH, Chen S, Corpe C, Dutta A, Dutta SK, Levine M. Vitamin C as an antioxidant: evaluation of its role in disease prevention. J Am Coll Nutr. 2003 Feb;22(1):18-35. doi: 10.1080/07315724.2003.10719272. PMID: 12569111.
7. Li XY, Meng L, Shen L, Ji HF. Regulation of gut microbiota by vitamin C, vitamin E and β-carotene. Food Res Int. 2023 Jul;169:112749. doi: 10.1016/j.foodres.2023.112749. Epub 2023 Mar 24. PMID: 37254375.
8. Jiang Q. Natural forms of vitamin E: metabolism, antioxidant, and anti-inflammatory activities and their role in disease prevention and therapy. Free Radic Biol Med. 2014 Jul;72:76-90. doi: 10.1016/j.freeradbiomed.2014.03.035. Epub 2014 Apr 3. PMID: 24704972; PMCID: PMC4120831.
9. Health Claims Vitamin B12; https://ec.europa.eu/food/food-feed-portal/screen/health-claims/eu-register/details/POL-HC-6489; last checked 28.04.2025
10. Calder PC. Omega-3 fatty acids and inflammatory processes: from molecules to man. Biochem Soc Trans. 2017 Oct 15;45(5):1105-1115. doi: 10.1042/BST20160474. Epub 2017 Sep 12. PMID: 28900017.
11. Seethaler B, Lehnert K, Yahiaoui-Doktor M, Basrai M, Vetter W, Kiechle M, Bischoff SC. Omega-3 polyunsaturated fatty acids improve intestinal barrier integrity-albeit to a lesser degree than short-chain fatty acids: an exploratory analysis of the randomized controlled LIBRE trial. Eur J Nutr. 2023 Oct;62(7):2779-2791. doi: 10.1007/s00394-023-03172-2. Epub 2023 Jun 15. PMID: 37318580; PMCID: PMC10468946.