In this episode, we highlight vitamin D₃ in gastrointestinal health, with a focus on intestinal barrier function and the gut-immune axis. We discuss how vitamin D is metabolized into its active form, 1,25-dihydroxyvitamin D, and how 1,25-dihydroxyvitamin D can support the intestinal mucosa, while highlighting the intestinal epithelium and immune cells in the lamina propria. Through this, we further detail the role of regulatory T cells in supporting immune balance and modulating immune function.
Topics:
1. Introduction
- Highlighting intestinal barrier function and the gut-immune axis with a focus on vitamin D₃
2. Vitamin D Synthesis and Metabolism
- Skin and 7-dehydrocholesterol; dietary intake.
- Transported through the bloodstream bound to vitamin D binding protein.
- First hydroxylation in the liver to form 25-hydroxyvitamin D₃ (25(OH)D₃).
- Testing.
- Second hydroxylation in the kidney to form the active 1,25 dihydroxyvitamin D₃ (1,25(OH)₂D₃).
- Local activation also occurs.
3. Intestinal Barrier Anatomy
- The intestinal epithelium forms a selectively permeable monolayer that interfaces with the gut lumen.
- Covered by a mucus layer: mucins, antimicrobial peptides, secretory IgA.
- Mucus layer provides physical and biochemical protection.
- Tight junction proteins and paracellular permeability.
- Molecules crossing the epithelium.
- Disruption of tight junctions, immune cell exposure to luminal contents.
- The lamina propria and Gut-Associated Lymphoid Tissue (GALT).
- Maintaining tolerance while defending against pathogens.
4. Vitamin D’s Role in Barrier Support and Immune Modulation
- 1,25-dihydroxyvitamin D₃, tight junction integrity, immune regulation, and more.
- Regulatory T Cells (Tregs) and immune balance.
5. Vitamin D₂ and D₃
- D₃ (cholecalciferol) is more biologically effective and binds DBP more strongly.
6. Vitamin D Levels
- Levels observed in autoimmune conditions, IBS, and more.
- Symptoms.
- Insufficient and excessive levels of vitamin D can be detrimental.
- Multi-system.
7. Conclusion
- Multifactorial: Numerous factors regulate vitamin D levels.
- Gastrointestinal health root cause approach.
Thanks for tuning in!
Get Chloe's Book Today! "75 Gut-Healing Strategies & Biohacks"
Follow Chloe on Instagram @synthesisofwellness
Follow Chloe on TikTok @chloe_c_porter
Visit synthesisofwellness.com to purchase products, subscribe to our mailing list, and more!