A 82-year-old woman is brought to the hospital because of functional decline at home and an inability to care for herself. She has a prior history of hypertension and dyslipidemia, and her medications include hydrochlorothiazide and atorvastatin. She looks disheveled, pale, and has muscle wasting; her heart and lungs are clear and there are no focal neurologic findings. Her hemoglobin is 9 g/dL, MCV 105 fL,
WBC 4500/mL, and platelets 100,000/mL. The blood film shows macrocytic RBCs and hypersegmented
neutrophils. Which of the following vitamin deficiencies is most likely responsible for her pancytopenia?
(A) B12 (cyanocobalamin)
(B) folate
© pyridoxine
(D) thiamine
(E) riboflavin
solution
(B) The macrocytosis and hypersegmented neutrophils suggests a megaloblastic anemia due to either folate or vitamin B12 deficiency. Folate deficiency results from decreased intake and malabsorption. Body folate stores are meager (only 3 months on average, compared to a few years for vitamin B12), and therefore easily depleted when intake is poor. Alcohol itself can depress folate levels acutely, and also can cause pancytopenia directly