Diagnosis of iron deficiency

Serum iron concentrations do not reflect total body iron stores. The best measure of total body iron stores is serum ferritin, which is low in iron deficiency.

Ferritin may be elevated in patients with acute or chronic inflammatory conditions or infections. In these patients, it may be difficult to diagnose iron deficiency because their ferritin may not be an accurate representation of their iron stores; however, iron deficiency is unlikely if serum ferritin concentration is more than 100 micrograms/L.