Carl Peter Henrik Dam was a Danish biochemist and physiologist. The Nobel Prize in Physiology or Medicine 1943, announced October 26, 1944. Henrik Dam (1/2), “for his discovery of vitamin K”. Edward A. Doisy (1/2), “for his discovery of the chemical nature of vitamin K”. Henrik Dam: born 1895, Copenhagen, Denmark. Edward A. Doisy: born 1893, Hume, IL, USA. Wiki link Wiki link Data: the Nobel Foundation (CC0).