Serum Total Iron Binding Capacity
- Sample Type
- Serum
- Fasting
- Required
- Unit
- µg/dL
Function
Total Iron Binding Capacity (TIBC) is a blood test that measures the blood's capacity to bind iron with transferrin. Transferrin is a protein produced by the liver that transports iron throughout the body. TIBC indirectly measures the amount of transferrin available in the blood.
Why it is Ordered
Physicians order TIBC when they suspect iron deficiency or iron overload (hemochromatosis). It is rarely ordered alone and is usually part of an 'Iron Panel' that includes serum iron, ferritin, and transferrin saturation. Symptoms justifying this test include chronic fatigue, pale skin (pallor), dizziness, or joint pain.
Associated Conditions
- Iron Deficiency Anemia: In this state, the body produces more transferrin to 'hunt' for scarce iron, leading to an elevated TIBC.
- Hemochromatosis: A genetic condition where the body stores too much iron; here, transferrin sites are saturated, leading to a low TIBC.
- Anemia of Chronic Disease: Conditions like cancer or chronic infections often show low TIBC because the body purposefully sequesters iron away from pathogens.
- Liver Disease: Since the liver produces transferrin, cirrhosis or hepatitis can lead to decreased TIBC levels.
Understanding TIBC helps differentiate between different types of anemia, which is vital because treating the wrong type of anemia with iron supplements can be toxic.
Check Your Result
Check Your Result
Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
TIBC results can be confounded by liver function, nutritional status, and inflammation. Inflammation (measured by CRP) can artificially lower TIBC because transferrin is a 'negative acute-phase reactant.' Oral contraceptives and pregnancy can also increase TIBC levels without an actual iron deficiency. A second opinion ensures these variables are accounted for before starting iron therapy.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Serum Total Iron Binding Capacity:
Official Sources
- Iron Deficiency Anemia - Hematology.orghematology.org
Research & Guidelines
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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