Q. A 60 year-old female presents to clinic with encephalopathy. Her son notes that the patient has difficulties with orientation, grooming, and driving that started 2 days ago. She has also fallen several times during the last 1 week. Her past medical history includes chronic alcohol use involving 3-6 beers daily for the last 20 years. Her vitals are as follows: Temperature 37.6° F, blood pressure 140/80 mmHg, HR 60, respiratory rate 12, oxygen saturation 94% on room air. On neurological examination, patient is disoriented to person, place, and time. She is noted to confabulate answers during the examinations. She has difficulties following commands. Her neurological exam reveals gaze evoked binocular horizontal nystagmus and a wide-based gait. The remainder of her neurological exam was unremarkable. Her MRI brain with and without contrast reveals atrophy of her mammillary bodies. Which of the following supplements should be given to this patient to prevent worsening of neurological symptoms?