welche mikronährstoffe sollte man testen lassen — when to see a doctor?

Which micronutrients should you test? The answer depends on your health status, symptoms, diet, and risk factors. Routine testing of all micronutrients is not recommended for healthy individuals. Clinically relevant tests include vitamin D, vitamin B12, folate, iron (ferritin, transferrin), magnesium, zinc, and selenium – especially if you have symptoms like fatigue, neurological issues, bone pain, or if you follow a vegan diet, have gastrointestinal disorders, or are elderly. DNA tests (e.g., VDR for vitamin D metabolism, FUT2 for B12 absorption) can indicate genetic predispositions but do not replace blood tests. The effect sizes are small; blood testing is far more reliable for safety (e.g., vitamin D toxicity). When to see a doctor? If you have persistent deficiency symptoms, before taking high-dose supplements, if you have chronic diseases (kidney, liver, GI), after bariatric surgery, or if you are pregnant, breastfeeding, or elderly. Avoid over-testing: without medical interpretation, results can be misleading. Evidence: recommendations are based on clinical guidelines (e.g., DGE, Endocrine Society) and observational studies. Genetic associations are mechanistic or moderate. Bottom line: targeted testing with medical guidance is useful; DNA tests provide context but not diagnoses.