Recurring Delirium in a patient with a surgically altered GI tract

Vitamin B12 deficiency is associated with a spectrum of neuro-psychiatric manifestations including memory impairment, irritability, depression, dementia, schizophrenia and psychosis [1]. B12 deficiency results from inadequate intake, impaired absorption, or increased nutritional requirements [2]. Vitamin B12 is catalyzed after binding to intrinsic factor in the stomach and absorbed in the ileum [3]. Bariatric surgery patients often develop B12 deficiency due to malabsorption. In patients who undergo Roux-en-Y gastric bypass procedure, most of the stomach and duodenum are bypassed, limiting the breakdown of vitamin B12 and its subsequent binding with intrinsic factor, which can result in overall B12 deficiency [4].