Review Question - QID 213348

A 34-year-old female presents to the clinic for tingling of her feet over the past 2 months. She reports that ever since her vacation to the Rocky Mountains 3 months ago, she began feeling “pins and needles” at her feet. She denies weight loss, fever, palpitations, chest pain, gastrointestinal symptoms, or rashes, but endorses lightheadedness and fatigue. Her past medical history is significant for gastric bypass surgery 4 year agos for weight loss. A physical examination demonstrates decreased vibration and pinprick sensation at the toes bilaterally. A peripheral blood smear is shown in Figure A. What is the most appropriate treatment for this patient?