Vitamin B1 deficiency is likely to be undiagnosed

October 6, 2014

Scientists warn that particularly in patients who suffer from alcoholism, anorexia or AIDS, brain damaging thiamine deficiency is missed on clinical examination in up to 80% of cases.

According to the US neurologists vitamin B1 deficiency can cause a potentially fatal brain disorder called Wernicke encephalopathy (1). Symptoms can include confusion, hallucinations, coma, loss of muscle coordination and vision problems such as double vision and involuntary eye movements. Acute encephalo-pathy, caused by metabolic disorders and toxic substances, has a rapid onset of between hours and days. Untreated, Wernicke encephalopathy can lead to Korsakoff syndrome, characterized by profound memory loss and inability to form memories. As permanent brain damage may occur, an organized approach is needed to make an accurate and rapid diagnosis.

Thiamine deficiency is likely to be underdiagnosed. Although clinical studies find a rate of 0.13% or less, autopsy studies show a prevalence as high as 2.8%. Particularly in those who suffer from alcoholism, anorexia or AIDS, the diagnosis is missed on clinical examination in 75 to 80% of cases, the neurologists note. Wernicke encephalopathy is a medical emergency that requires immediate (intravenous) thiamine treatment. In the absence of treatment, deficiency can lead to irreversible brain damage and death with an estimated mortality of 20%.


  1. McCoyd M. et al. Not enough vitamin B1 can cause brain damage. Scientific American Medicine. Published online September 2014.