Guideline for the laboratory diagnosis of functional iron deficiency

Functional iron deficiency (FID) is a state in which there is insufficient iron incorporation into erythroid precursors in the face of apparently adequate body iron stores, as defined by the presence of stainable iron in the bone marrow together with a serum ferritin value within normal limits (Macdougall et al, 1989). In its broadest sense this definition encompasses the partial block in iron transport to the erythroid marrow seen in subjects
with infectious, inflammatory and malignant diseases, and is a major component of the anaemia of chronic disease (ACD).

British Journal of Haematology, 2013, 161, 639–648  doi:10.1111/bjh.12311