Doisy, Edward Adelbert (1893-1986), an American chemist, determined the nature of vitamin K, which helps the liver produce prothrombin, one of the clotting factors in blood. He isolated and synthesized pure vitamin K1. Its use saves many lives each year. In 1943, Doisy and Danish chemist Henrik Dam shared the Nobel Prize in physiology or medicine for their work with vitamin K. Doisy is also known for his work in isolating the female sex hormones estrone and estradiol. He was born in Hume, Illinois.
