Important laboratory measure of iron status during the past quarter century. Phlebotomy studies in normal subjects have demonstrated that 1 µg/L serum ferritin corresponds to 8-10 mg or 120 µg storage iron/kg body weight,⁷ although a log transformation gives a more accurate estimate.⁸ Numerous studies have demonstrated its superiority over other iron-related measurements in identifying iron deficiency anemia. In 55 studies culled from 1179 relevant citations, receiver-operator characteristic curves in 2579 subjects gave a mean area for the serum ferritin of 0.95 ± 0.1 (95% confidence limits) as compared with 0.77 for the ZPP, 0.76 for the MCV, and 0.74 for the transferrin saturation.⁹ The well-known limitation of the serum ferritin is the elevation in values independent of iron status that occur with acute or chronic inflammation, malignancy, liver disease, and alcoholism.