was tun bei eisenmangel — what are common causes?

Common causes of iron deficiency include inadequate dietary intake (e.g., vegan/vegetarian diets without iron-rich alternatives), chronic blood loss (e.g., heavy menstruation, gastrointestinal bleeding), and malabsorption (e.g., celiac disease, atrophic gastritis, post-bariatric surgery). Increased physiological demands during pregnancy, growth spurts, or endurance training can also deplete iron stores. The provided knowledge context does not contain specific evidence on iron deficiency; this answer reflects standard medical practice. A blood test measuring ferritin, hemoglobin, and transferrin saturation is essential for diagnosis. If a source of bleeding or absorption issue is suspected, further medical evaluation is warranted. Do not self-supplement without confirmed deficiency, as iron overload (hemochromatosis) poses health risks. Evidence: practice-based, not supported by the given context.