Nearly two thirds of American adults are either overweight or obese. Accordingly, bariatric surgery experienced explosive growth during the past decade. Current estimates place the worldwide volume of bariatric procedures at greater than 300,000 cases annually. Micronutrient deficiencies are well-described following bariatric surgery, and they may present with devastating and sometimes irreversible neurologic manifestations. Clinical symptoms range from peripheral neuropathy to encephalopathy, and are most commonly caused by thiamine, copper, and B(12) deficiencies.