Vitamin B12

Detect B₁₂ deficiency as in pernicious anemia; diagnose folic acid deficiency; evaluate hypersegmentation of granulocyte nuclei; follow up MCV >100; diagnose macrocytic anemia; diagnose megaloblastic anemia; evaluate alcoholism, prenatal care; evaluate malabsorption, neurological disorders, or the elevation of B₁₂ as seen in liver cell damage or myeloid leukemia.