[Thiamin: Simply a vitamin?].

Vitamin B1 also known as thiamin is an essential vitamin assuring body functioning and comes exclusively from food. Vitamin B1 deficiency is an under-diagnosed disease because it is less frequently suspected in high income countries. However, its risk factors, like alcohol and malnutrition, are common in the general population. Thiamin deficiency can lead to three clinical entities, Gayet-Wernicke encephalopathy, which can progress to Korsakoff encephalopathy, wet Beriberi and its dry form. These diseases are associated with high mortality and heavy long-term sequelae. Rapid diagnosis enables timely treatment.