What is the primary laboratory measure used to assess iron stores in the body?

What is the primary laboratory measure used to assess iron stores in the body?

• A. Transferrin
• B. Serum iron
• C. Ferritin
• D. Hemoglobin

Answer: (C)

Ferritin level is the best indicator of the body's iron stores because ferritin is the intracellular iron storage protein, and the amount present in serum mirrors how much iron is stored overall. Low ferritin reliably indicates depleted iron stores and iron deficiency, while a normal or high ferritin usually means stores are sufficient, though inflammation or liver disease can raise ferritin independently of storage, so interpretation should consider the clinical context. Serum iron measures circulating iron bound to transferrin, not stored iron, and can be affected by recent intake or inflammatory states. Transferrin and transferrin saturation reflect transport capacity and iron availability in the blood, not how much iron is stored. Hemoglobin shows the consequence of iron status on red blood cell production but does not directly measure stores.

Ferritin level is the best indicator of the body's iron stores because ferritin is the intracellular iron storage protein, and the amount present in serum mirrors how much iron is stored overall. Low ferritin reliably indicates depleted iron stores and iron deficiency, while a normal or high ferritin usually means stores are sufficient, though inflammation or liver disease can raise ferritin independently of storage, so interpretation should consider the clinical context. Serum iron measures circulating iron bound to transferrin, not stored iron, and can be affected by recent intake or inflammatory states. Transferrin and transferrin saturation reflect transport capacity and iron availability in the blood, not how much iron is stored. Hemoglobin shows the consequence of iron status on red blood cell production but does not directly measure stores.