Henrik Dam is best known for his discovery of vitamin K, which gives blood the ability to clot, or coagulate. The discovery of vitamin K dramatically reduced the number of deaths by bleeding during surgery, and for the discovery Dam received the 1943 Nobel Prize in medicine and physiology. (Edward A. Doisy, the American biochemist who isolated and synthetically produced vitamin K, shared this prize with Dam.)

Carl Peter Henrik Dam was born in Copenhagen, Denmark, on February 21, 1895. His interest in science was shaped at least in part by his background. His father, Emil Dam, was a pharmaceutical chemist who wrote a history of pharmacies in Denmark. His mother, Emilie Peterson Dam, was a schoolteacher. He attended the Polytechnic Institute in Copenhagen, from which he received his master of science degree in 1920. He was associated with the Royal School of Agriculture and Veterinary Medicine in Copenhagen for the next...