Iron Saturation

What is Iron Saturation?

Iron saturation, also called transferrin saturation, measures the percentage of transferrin (the iron transport protein) that is actually carrying iron. It’s calculated by dividing serum iron by total iron-binding capacity (TIBC) and multiplying by 100. This ratio provides insight into how much of the body’s iron transport capacity is being utilized.

Why is it Tested?

Iron saturation is measured to evaluate iron status and diagnose iron-related disorders. It’s particularly useful for detecting iron deficiency, iron overload conditions like hemochromatosis, and monitoring response to iron supplementation. Unlike serum iron alone, which fluctuates throughout the day, iron saturation provides a more stable assessment of iron availability.

Normal Ranges

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low Iron Saturation

Low saturation indicates insufficient iron relative to transport capacity and may suggest:

• Iron deficiency anemia
• Chronic blood loss
• Inadequate dietary iron absorption
• Chronic kidney disease
• Inflammatory conditions affecting iron utilization

High Iron Saturation

Elevated saturation suggests excess iron relative to binding capacity and may indicate:

• Hereditary hemochromatosis
• Iron overload from supplements or transfusions
• Liver disease affecting iron metabolism
• Certain genetic disorders
• Acute iron poisoning (very high levels)

How to Track Over Time

Monitoring iron saturation trends helps evaluate iron status changes and treatment responses. During iron supplementation, rising saturation indicates improving iron availability, while persistently low levels may suggest absorption problems or ongoing losses. In iron overload conditions, declining saturation can indicate successful therapeutic intervention.