The unusual nutritional and toxin-related underproduction anemias: approaching the riddle beyond iron, cobalamin, and folate.

"Anemias beyond iron, vitamin B12, and folate deficiencies" covers a wide array of everything which lies beyond commonly seen anemias caused by deficiencies of three micronutrients. Although anemias due to deficiencies of iron, B12, and folate are common in daily practice and account for at least one-third of anemia etiologies in older adults, it is not uncommon to encounter other nutritional and toxin-induced underproduction anemias. The combination of thorough clinical examination, careful peripheral blood smear review, and judicious selection of supporting laboratory studies is typically sufficient to make an assertive diagnosis of those cases. Moreover, the recognition of overlapping features with primary hematologic disorders and the diagnostic limitations of conventional testing are important for clinicians to determine when to refer to a hematologist. Herein, we discuss clinical features and diagnostic approaches to unusual underproduction anemias due to deficiencies of vitamin B6 and copper, and toxic effects of alcohol and lead.