Water-soluble vitamins - B complexDownloads

A 48-year-old woman is brought to the emergency department by police because of confusion and agitation. Her medical record indicates that she has peptic ulcer disease that is treated with omeprazole. The patient's brother arrives shortly after. He reports that she drinks around 17 oz. of vodka daily. Neurological examination shows horizontal nystagmus. Her gait is wide-based with small steps. Her hemoglobin concentration is 9.1 g/dL. A peripheral blood smear shows hypersegmented neutrophils. Homocysteine levels are elevated. Methylmalonic acid levels are within normal limits. Which of the following is the most likely direct cause of this patient's anemia?

A 34-year-old man presents with dysphagia. The patient says that he has pain on swallowing which gradually onset 2 weeks ago and has not improved. He denies any change in diet but does say that he recently returned from a prolonged work trip to the Caribbean. No significant past medical history or current medications. On physical examination, the patient looks pale. His tongue is swollen and has a beefy, red appearance. Angular stomatitis is present. Laboratory findings are significant for macrocytic, megaloblastic anemia, decreased serum folate, increased serum homocysteine, and normal methylmalonic acid levels. Which of the following conditions most likely caused this patient’s symptoms?