What to watch with VDR and gut health?

The vitamin D receptor (VDR) is a key regulator in gut health: it controls calcium/phosphate absorption, modulates immune responses, and influences intestinal barrier integrity and the microbiome. Common VDR polymorphisms (e.g., rs2228570, rs1544410) have been associated with inflammatory bowel disease, irritable bowel syndrome, and altered gut microbiota – but effect sizes are small and ancestry-dependent. Crucially, a DNA test for VDR variants cannot replace clinical assessment. Blood levels of 25-hydroxyvitamin D are more actionable for gut health and can be optimized through sun exposure or supplementation. Consumer tests like MyBody-X provide only suggestive clues, not validated recommendations. For persistent gut issues, additional biomarkers (calprotectin, zonulin) or microbiome profiling should be considered.