See One, B1, Treat One: Identifying and Managing Thiamine Deficiency in a Patient With Altered Mental Status.

Nutritional deficiencies in the United States are relatively uncommon due to federal regulations surrounding the fortification of food. As a result, the clinical syndromes that result from nutritional deficiencies are not commonly seen, making them less likely to be encountered in the clinical setting. Thiamine deficiency in particular is an important nutritional deficiency to consider, as the presentation is highly variable and can include encephalopathy and multiple neurologic findings. We present a case of altered mental status that appears to be Wernicke's encephalopathy due to the rapid improvement of symptoms with intravenous thiamine supplementation, corroborated by a low serum thiamine level. Assessing access to food is a critical piece of history in making this diagnosis, and early recognition can promote fully supplementing patients with thiamine to prevent ongoing thiamine deficiency and possible Korsakoff syndrome.