Iron Saturation

This number represents the amount of iron-binding sites that are occupied. Iron saturation is a better index of iron stores than serum iron alone. Iron saturation is calculated as

% Saturation = Serum iron/TIBC ƒ — 100

Normal range: 20 " “50%.

Use

Differential diagnosis of anemias

Screening for hereditary hemochromatosis

Interpretation

Increased In

Hemochromatosis

Hemosiderosis

Thalassemia

Birth control pills ( ≤75%)

Ingestion of iron ( ≤100%)

Iron dextran administration causes increase for several weeks (may be >100%)

Vitamin B6 deficiency

Aplastic anemias

Decreased In

Iron deficiency anemia (usually <10% in established deficiency)

Anemias of infection and chronic diseases (e.g., uremia, RA, some neoplasms)