welche vitamine fehlen bei haarausfall — can a microbiome test help?

The question of which vitamins are missing in hair loss cannot be answered universally. Common suspects include iron, zinc, biotin, vitamin D, and B vitamins. However, true deficiencies are relatively rare and should be confirmed by medical blood tests, not by self-tests. A microbiome test (gut or scalp) currently cannot reliably indicate which vitamins are deficient. Research on the gut-hair axis and scalp microbiome is still emerging; there are no validated microbiome biomarkers for vitamin deficiency. Many commercial tests overstate their predictive power. A more evidence-based approach is targeted blood testing for ferritin, vitamin D, zinc, and thyroid function. For diffuse hair loss, a doctor should also rule out hormonal imbalances or stress. Evidence: unclear – no direct studies from the provided context. Sources: none specific PMIDs available.