AMBOSS 200 High Yield (HY) Concepts for Step 2 Practice Test

Ferritin reflects the body's iron stores. In iron deficiency anemia, those stores are depleted, so serum ferritin falls and becomes the most sensitive marker of iron deficiency. This is why ferritin is typically decreased. (Note that ferritin can be normal or elevated in inflammation or chronic disease, which can mask deficiency, but in pure iron deficiency the level is decreased.)