Henrik Dam
Dam, Henrik (1895-1976), a Danish biochemist, discovered vitamin K, which gives the blood the ability to clot. He shared the 1943 Nobel Prize in physiology or medicine with American biochemist Edward Adelbert Doisy.
Carl Peter Henrik Dam was born in Copenhagen, Denmark, and educated at the Polytechnic Institute in Copenhagen. He received his master's degree in 1920 and then joined the Royal School of Agriculture and Veterinary Medicine in Copenhagen, where he spent three years as an assistant instructor in chemistry. He then worked in the physiological laboratory at the University of Copenhagen. He became an assistant professor of biochemistry in 1928 and associate professor in 1929. During this time, he earned his doctorate.
In the late 1920's, Dam began experiments to discover how hens synthesized cholesterol. He found that when he fed the hens a special diet, they hemorrhaged under the skin and their blood was slow to coagulate. Dam decided that a vitamin in foods must give blood the ability to clot. He fed the hens hempseed, tomatoes, green leaves, and hog liver and found that those foods contained the vitamin that prevented bleeding. He called the vitamin “K,” from the German word koagulation. Doisy then isolated and synthetically produced vitamin K, and Dam and Doisy subsequently shared the Nobel Prize in 1943. Their discovery dramatically reduced the number of deaths by bleeding during surgery.
In 1940, while Dam was in the United States on a lecture tour, Nazi Germany invaded Denmark. Dam stayed in the United States and became a senior research associate at the University of Rochester's Strong Memorial Hospital. In 1945, he joined the Rockefeller Institute for Medical Research, now Rockefeller University. He returned to Denmark in 1946 to become head of the biology department at the Polytechnic Institute. In 1956, he was appointed head of the Danish Public Research Institute.