Christiaan Eijkman (1858-1930), Dutch physician and Nobel laureate, born in Nijkerk, and educated at the University of Amsterdam. Working (1886-1897) on the island of Java, he found that fowl fed only polished rice developed a disease closely resembling beriberi, but fowl fed only unpolished rice remained healthy. Eijkman concluded that disease could be caused by depriving the body of certain unknown substances, later defined as vitamins. Beriberi was later found to be caused by a deficiency of vitamin B₁, or thiamine. For his work in the field of nutrition, Eijkman was a cowinner of the 1929 Nobel Prize in physiology or medicine.