<p>An inadequate supply of thiamine (vitamin Bx) to the brain can result in Wernicke’s encephalopathy, which is an acute neuropsychiatric disorder. This article explains the known risk of thiamine deficiency in people who are dependent on or misuse alcohol. The importance of making parenteral vitamin supplements available to patients in a community alcohol service is outlined. A project that has provided intramuscular thiamine supplementation to reduce the likelihood of long-term brain damage is described.</p>