A 23-year-old pregnancy woman is referred by her obstetrician for evaluation of anemia. She is in her fourth month of pregnancy and has no history of anemia; her grandfather had pernicious anemia. Her hemoglobin is 10 g/dL (normal, 12-16 g/dL).
If this woman has macrocytic anemia, an increased serum concentration of transferrin, and a normal serum concentration of vitamin B12' the most likely cause of her anemia is deficiency of (LQ)
Deficiencies of folic acid or vitamin BIZ are the most common causes of megaloblastic anemia. If a patient with this type of anemia has a normal serum vitamin B12 concentration, folate deficiency is the most likely cause of the anemia.