welche vitamine fehlen bei haarausfall — what does this mean exactly?

The question 'Which vitamins are missing in hair loss?' aims to identify a possible nutrient deficiency as a cause of increased hair shedding. Deficiencies in certain micronutrients can indeed disrupt the hair cycle. Most commonly cited are iron, vitamin D, vitamin B12, biotin, zinc, and folate. However, the evidence is nuanced: a clear causal link exists mainly for iron deficiency (especially in women with heavy menstruation) and severe vitamin D deficiency. Biotin deficiency is rare and usually occurs only in genetic disorders or extreme malnutrition. Importantly, hair loss has many causes – genetic predisposition (androgenetic alopecia), hormonal changes, stress, thyroid disorders, or medications. Vitamin deficiency is just one possible factor. The DNA or biomarker tests mentioned in the context (e.g., rs1205 for CRP) cannot detect specific vitamin deficiencies. A blood test ordered by a physician (ferritin, 25-OH vitamin D, vitamin B12, zinc) is the more reliable approach. Without medical evaluation and targeted lab diagnostics, the question remains speculative. The answer should therefore be conservative: there is no universal vitamin list for hair loss; individual diagnostic workup is essential.