Can VDR help with fatigue?

Whether VDR (vitamin D receptor) can help with fatigue is not clearly established by current science. VDR is a nuclear receptor that mediates vitamin D signaling. Vitamin D deficiency is associated with fatigue, muscle weakness, and reduced physical performance – mainly from observational studies. Genetic variants in the VDR gene (e.g., FokI, BsmI, TaqI) are linked to altered receptor function, but their effect on fatigue is small and inconsistent. Robust randomized controlled trials testing VDR-guided supplementation for fatigue are lacking. Therefore, it is not justified to change diet or supplement use based solely on a VDR genetic test. A blood test for 25-hydroxyvitamin D is more informative. If deficiency is confirmed, supplementation may improve fatigue – regardless of VDR genotype. Caution: vitamin D is fat-soluble and can be toxic in excess. The evidence is mostly mechanistic and observational, insufficient for personalized recommendations.