Iron (serum) — Normal Range & Interpretation

Clinical Context

Serum iron measures the amount of iron bound to transferrin circulating in the bloodstream. Clinicians order it alongside ferritin, total iron-binding capacity (TIBC), and transferrin saturation to evaluate anemia, suspected iron overload, and nutritional status. Serum iron alone lacks specificity, so NPs interpret it within a full iron panel and the patient's clinical picture.

Low serum iron points to iron deficiency anemia from blood loss, including menstrual bleeding and occult gastrointestinal bleeding, as well as inadequate dietary intake, malabsorption from celiac disease or bariatric surgery, and pregnancy. Anemia of chronic disease also lowers serum iron despite adequate stores. Elevated serum iron reflects hereditary hemochromatosis, repeated transfusions, hemolysis, acute iron ingestion, and excessive supplementation. Liver disease and certain hepatitis presentations raise levels through hepatocyte release.

What the AANP exam actually tests on serum iron: pattern recognition across the iron panel rather than isolated values. Expect questions linking low iron, low ferritin, high TIBC, and low transferrin saturation to iron deficiency anemia, contrasted with low iron, high ferritin, and low TIBC in anemia of chronic disease. Test items also pair high serum iron and high ferritin with hemochromatosis screening, and they highlight first-line workup for microcytic anemia, dietary counseling on heme versus non-heme iron, and the role of vitamin C in enhancing absorption.

Related Labs

• HbA1c — %
• ESR — mm/hr
• CRP — mg/dL
• hs-CRP — mg/L
• Uric Acid — mg/dL

Sources

• MedlinePlus
• ARUP Consult