These recommendations are based on the clinical guidelines Alcohol-use disorders: diagnosis and clinical management of alcohol-related physical complications, published by the National Institute for Health and Clinical Excellence (NICE) [NICE, 2010a], and are consistent with guidelines published by the National Treatment Agency for Substance Misuse [Raistrick et al, 2006] and the Scottish Intercollegiate Guidelines Network (SIGN) [SIGN, 2003].

• People who are dependent on alcohol are often malnourished and deficient in vitamins. In particular, thiamine deficiency is common due to poor diet, poor absorption (caused by gastritis), and a high demand for the vitamin (it is a coenzyme in alcohol metabolism).
• Thiamine deficiency can cause Wernicke's encephalopathy, a condition that is reversible with thiamine supplements. However, if left untreated, Korsakoff's syndrome may develop, causing irreversible brain damage.
• Dose of thiamine
• Most people who are in reasonable health with an adequate diet should receive oral thiamine 200–300 mg per day, taken in divided doses (to aid absorption), while they are undergoing detoxification or during periods when they are drinking very excessively [BNF 59, 2010].
• Lower doses (thiamine 10–25 mg) are recommended by the British National Formulary if there is a suspicion of chronic deficiency during the maintenance stage [BNF 59, 2010]. However, as tablets are most readily available at a dose of 50 mg, and it is very unlikely thiamine will cause harm at higher doses, CKS recommends that 50 mg should be taken daily.
• For the available evidence for the use of thiamine in the treatment of alcohol-dependent people, see Thiamine in alcohol-dependency.