Lay opinion vs evidence: Vitamin D Männer

Lay opinion often overstates vitamin D's benefits for men, claiming it boosts testosterone and prevents cancer. Evidence is more nuanced. For bone health, vitamin D is strongly supported when deficiency exists (human-strong). For testosterone, meta-analyses show only minor, clinically insignificant effects. Immune modulation is complex – deficiency increases infection risk, but supplementation without deficiency shows no clear benefit. DTC tests (e.g., MyBody-X) lack clinical validation for diagnosis. Evidence for general high-dose supplementation in healthy men is weak to moderate. Safety: vitamin D is fat-soluble; overdose can cause hypercalcemia. Conclusion: supplement only if deficiency is confirmed via lab testing, not based on lay assumptions or direct-to-consumer genetic tests.