Iron
Serum iron measures the amount of iron bound to transferrin circulating in the blood at the time of the test. It represents iron in transit between storage (ferritin) and utilization (hemoglobin synthesis). Serum iron fluctuates significantly throughout the day, after meals, and with acute illness.
Why it matters: Low serum iron alongside low ferritin is the pattern of iron deficiency; high serum iron with high ferritin is associated with iron overload. On its own, serum iron is unreliable — it varies considerably through the day and with recent meals, inflammation, and infection — so it is most useful as part of a full iron panel.
May increase with:
May decrease with:
What is Iron?
Serum iron measures the amount of iron bound to transferrin circulating in the blood at the time of the test. It represents iron in transit between storage (ferritin) and utilization (hemoglobin synthesis). Serum iron fluctuates significantly throughout the day, after meals, and with acute illness.
What might a high or low Iron mean?
Low serum iron alongside low ferritin is the pattern of iron deficiency; high serum iron with high ferritin is associated with iron overload. On its own, serum iron is unreliable — it varies considerably through the day and with recent meals, inflammation, and infection — so it is most useful as part of a full iron panel.
What is the typical reference range for Iron?
The general-population reference range shown here is 11 – 28 umol/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect Iron?
It may be higher with: Iron supplementation, Iron-rich diet (red meat, liver), Hemochromatosis, Hemolytic anemia (iron released from destroyed RBCs), Liver damage (iron released from hepatocytes), Multiple blood transfusions, Acute hepatitis, Lead poisoning. It may be lower with: Iron deficiency, Chronic blood loss, Chronic inflammation (hepcidin blocks iron release), Chronic kidney disease, Hypothyroidism, Malabsorption (celiac, gastric bypass), Heavy exercise, Menstruation.