USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 25-year-old man comes to his primary care physician's office because of weakness and fatigue for the past 2 months. The patient also reports recent sensations of pins and needles in his lower extremities. Physical examination shows conjunctival pallor and atrophic glossitis. Laboratory results show a hemoglobin level of 9.0 g/dl and a mean corpuscular volume of 110 fl/red cell. Which of the following vitamin deficiencies may lead to megaloblastic anemia?