Vitamin B12 deficiency can manifest with haematological, gastrointestinal and neuropsychiatric signs. The neuropsychiatric symptoms may be concurrent or precede the other symptoms. The reported case is a clinical case of delirium due to vitamin B12 deficiency in a female vegetarian patient. The patient was treated with vitamin B12 supplementation. Initially, it was difficult to diagnose this patient, who presented with delirium that could have been due to multiple causes. The finding underlines the importance of conducting a complete laboratory test panel for delirium, including the blood levels of vitamin B12.
European Journal of Clinical Nutrition (2013) 67, 996–997; doi:10.1038/ejcn.2013.128; published online 17 July 2013