Myths vs facts: Vitamin D 25-OH and gut health

Vitamin D 25-OH and gut health: myths vs facts. A common myth is that low vitamin D levels directly cause 'leaky gut'. Observational studies show an association between low 25-hydroxyvitamin D and increased intestinal permeability or dysbiosis, but causality is not established. Another myth: vitamin D supplements can cure gut disorders. While supplementation corrects deficiency and may support immune function, it is not a proven treatment for IBS or IBD. The evidence is mostly from cross-sectional and small intervention studies; large RCTs are lacking. Fact: adequate vitamin D status (30–50 ng/ml) is important for immune regulation and maintaining gut barrier integrity, but a single 25-OH test does not diagnose gut health. Consumer tests like MyBody-X provide a measurement but not a clinical diagnosis. Be cautious of exaggerated marketing claims.