Reference Number: 672
Year: 2024
Link: Link to original paper
Health: Crohns | IBS | Inflammatory bowel disease
Nutrition: Vitamin D
Summary
Abstract
Vitamin D, a crucial fat-soluble vitamin, is primarily synthesized in the skin upon exposure to ultraviolet radiation and is widely recognized as a bone-associated hormone. However, recent scientific advancements have unveiled its intricate association with gut health. The intestinal barrier serves as a vital component, safeguarding the intestinal milieu and maintaining overall homeostasis. Deficiencies in vitamin D have been implicated in altering the gut microbiome composition, compromising the integrity of the intestinal mucosal barrier, and predisposing individuals to various intestinal pathologies. Vitamin D exerts its regulatory function by binding to vitamin D receptors (VDR) present in immune cells, thereby modulating the production of pro-inflammatory cytokines and influencing the intestinal barrier function. Notably, numerous studies have reported lower serum vitamin D levels among patients suffering from intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, and celiac disease, highlighting the growing significance of vitamin D in gut health maintenance. This comprehensive review delves into the latest advancements in understanding the mechanistic role of vitamin D in modulating the gut microbiome and intestinal barrier function, emphasizing its pivotal role in immune regulation. Furthermore, we consolidate and present relevant findings pertaining to the therapeutic potential of vitamin D in the management of intestinal diseases.
Summary of Findings
Vitamin D is best known for helping our bodies absorb calcium and keep bones strong. But this paper highlights how it also plays a crucial role in keeping our gut healthy. The gut isn’t just for digestion, it is also a major part of our immune system and home to the gut microbiome. These bacteria help digest food, produce vitamins, and keep our immune system balanced.
The paper explains that vitamin D helps maintain the gut’s protective barrier, which prevents harmful bacteria and toxins from entering the body. When vitamin D levels are low, this barrier can weaken, leading to inflammation and increasing the risk of gut-related diseases like inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and celiac disease.
Vitamin D works by binding to special receptors in the body called vitamin D receptors (VDRs), which are found in many immune and gut cells. When activated, these receptors help reduce inflammation and support the growth of beneficial gut bacteria. Vitamin D also helps produce proteins that strengthen the connections between gut cells, making the barrier less “leaky.”
The paper reviews several studies showing that people with gut diseases often have low levels of vitamin D. Supplementing with vitamin D has been shown to improve symptoms in some patients, although results vary depending on the dose, duration, and individual differences like age and gender.
Interestingly, the relationship between vitamin D and the gut goes both ways. Not only does vitamin D affect the gut microbiome, but the gut bacteria can also influence how vitamin D is processed and used in the body. Some helpful bacteria can even boost the body’s ability to absorb vitamin D.
The paper also discusses how vitamin D affects the immune system. It helps immune cells behave in a balanced way, reducing harmful inflammation while still defending against infections. It encourages the production of anti-inflammatory substances and discourages the production of inflammatory ones.
In summary, vitamin D is more than just a bone-health nutrient. It plays a vital role in maintaining a healthy gut by supporting beneficial bacteria, strengthening the gut’s protective barrier, and regulating the immune system. Low vitamin D levels are linked to a higher risk of gut diseases, and it suggests that supplementation may help prevent or manage these conditions. However, more research is needed to understand exactly how much vitamin D is ideal and how it works in different people.
Significance for the baker
When we view vitamin D through the lens of the BALM protocol, a deficiency can ripple through all seven steps — particularly where food, fermentation, fibre, and emotional well-being intersect. The protocol’s emphasis on fermented wholegrain breads supports vitamin D metabolism by:
- Providing the prebiotic fibres that nourish vitamin D-enhancing gut microbes
- Offering a delivery vehicle for vitamin D-rich ingredients (eggs, fish, mushrooms, especially when exposed to sunlight)
- Supporting the fat absorption necessary for this fat-soluble vitamin
- Creating a circadian-supportive eating pattern that complements natural vitamin D rhythms
Regular midday sun (in the Northern hemisphere) or earlier in the South for 10-30 minutes without sunscreen can help with in-body production of vitamin D. Symbiotic eating of plant and animal sources of fats containing vitamin D are another option.
