A transferrin saturation of about 40% most likely indicates which iron status?

A transferrin saturation of about 40% most likely indicates which iron status?

• A. Iron deficiency
• B. Iron overload
• C. Normal iron status
• D. Anemia of chronic disease

Answer: (C)

Transferrin saturation shows how much of the transferrin iron-binding sites are actually occupied by iron. It’s calculated as serum iron divided by total iron-binding capacity (TIBC) times 100, and it usually falls in roughly the 20% to 50% range in healthy individuals, with many labs citing about 25%–35% as a typical midrange. A value around 40% means there’s enough circulating iron to bind transferrin, consistent with normal iron status. If iron were deficient, serum iron would drop and transferrin binding would be less filled, lowering the saturation. If iron were greatly excessive, saturation would be higher than normal, approaching or exceeding the upper limit. In anemia of chronic disease, iron is less available for binding and TSat is typically low despite inflammatory signals that can alter ferritin.

Transferrin saturation shows how much of the transferrin iron-binding sites are actually occupied by iron. It’s calculated as serum iron divided by total iron-binding capacity (TIBC) times 100, and it usually falls in roughly the 20% to 50% range in healthy individuals, with many labs citing about 25%–35% as a typical midrange.

A value around 40% means there’s enough circulating iron to bind transferrin, consistent with normal iron status. If iron were deficient, serum iron would drop and transferrin binding would be less filled, lowering the saturation. If iron were greatly excessive, saturation would be higher than normal, approaching or exceeding the upper limit. In anemia of chronic disease, iron is less available for binding and TSat is typically low despite inflammatory signals that can alter ferritin.