Is Nährstoffcheck useful for allergy?

A nutrient check (e.g., blood- or DNA-based) can provide information on the status of certain micronutrients relevant to immune function, such as vitamin D, zinc, or omega-3 fatty acids. However, it is not a tool for allergy diagnosis. Allergies are primarily confirmed through medical history, skin prick tests, and specific IgE measurements. The evidence linking individual nutrient deficiencies to allergy development or relief is mostly mechanistic or derived from observational studies; randomized controlled trials show inconsistent results. Therefore, a nutrient check may serve as supplementary information but cannot replace an allergological workup. Moreover, the clinical validity of many consumer nutrient tests is not established by independent studies. If supplements are taken based on such results, there is a risk of exceeding safe upper limits (e.g., vitamin E or selenium, for which EFSA updated ULs in 2023/2024). In summary, the usefulness of a nutrient check for allergy is limited; priority should be given to established diagnostics and targeted supplementation only under medical guidance.