Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1032 page)

   Acute and chronic infection

   Carcinoma

   Hypothyroidism

   Postoperative state and kwashiorkor

   Nephrosis (because of loss of iron-binding protein in urine)

   PA at onset of remission

   Menstruation (decreased by 10–30%)

   Limitations

   Serum iron is not reliable as the primary test to identify iron deficiency or screening for hemochromatosis and other iron overload diseases. For these conditions, a serum TIBC, percent transferrin saturation, and ferritin assay are recommended.

   Diurnal variation—normal values in midmorning, low values in midafternoon, very low values (approximately 10 μg/dL) near midnight. Diurnal variation disappears at levels <45 μg/dL.

   Iron dextran administration causes increase for several weeks (may be >1,000 μg/dL).

   Ingestion of oral contraceptives will elevate iron and/or total iron-binding capacity values.

   Not recommended for patients undergoing treatment with deferoxamine or other iron-chelating compounds.