BERIBERI
 (vitamin B-1 deficiency)

Dutch physician Christiaan Eijkman found that rice consumed without the bran covering resulted in Beriberi and thus discovered vitamin B.  He found that both the nervous system + carbohydrate metabolism were adversely affected without vitamin B. 
He and British biochemist Sir Frederick Gowland Hopkins were awarded the Nobel Prize in 1929. http://orthomolecular.org/history/index.shtml +
https://www.smithsonianmag.com/arts-culture/five-nobel-laureates-who-made-food-history-100322534/ 

volume 7 #6 Healthy Living quotes Reader's Digest WWII story of soldiers cured of beriberi after eating coconuts as islanders did.  Beriberi is psychiatric disease due to lack of vitamin B1. www.freedompressonline.com