Henrik Dam

Dam with his wife in Stockholm in 1946 Carl Peter Henrik Dam (21 February 1895 – 17 April 1976) was a Danish biochemist and physiologist.

He was awarded the Nobel Prize in Medicine in 1943 for joint work with Edward Doisy in discovering vitamin K and its role in human physiology. Dam's key experiment involved feeding a cholesterol-free diet to chickens. He initially replicated experiments reported by scientists at the Ontario Agricultural College (OAC). McFarlane, Graham and Richardson, working on the chick feed program at OAC, had used chloroform to remove all fat from chick chow. They noticed that chicks fed only fat-depleted chow developed hemorrhages and started bleeding from tag sites. Dam found that these defects could not be restored by adding purified cholesterol to the diet. It appeared that—together with the cholesterol—a second compound had been extracted from the food, and this compound was called the coagulation vitamin. The new vitamin received the letter K because the initial discoveries were reported in a German journal, in which it was designated as Koagulationsvitamin.