Beriberi

Beriberi ( /bɛriˈbɛri/) is a nervous system ailment caused by a thiamine (vitamin B₁) deficiency in the diet. Thiamine is involved in the breakdown of molecules such as glucose and is also found on the membranes of neurons. Symptoms of beriberi include severe lethargy and fatigue, together with complications affecting the cardiovascular, nervous, muscular, and gastrointestinal systems.