[A 40-year-old woman with anemia].

Background: Normally the body is unable to regulate its own iron content effectively by excretion. Urinary excretion of iron is about 10% of total daily loss.
Case Presentation: A 40-year-old woman was admitted to hospital because of anaemia that turned out to be caused by iron deficiency. In spite of extensive investigations no cause of her iron deficiency was identified. The urine was then tested for iron and showed excessive urinary loss as the cause of her anaemia. To our knowledge, extensive urinary iron loss as the cause of iron deficiency has not been reported before.