is Carl Henrik Dam's birthday. Dam was a Danish biochemist who discovered vitamin K. He was feeding chickens a cholesterol-free diet to find out if they needed cholesterol or not. He discovered the chickens could synthesize some of cholesterol, but several fell ill due to severe internal hemorrhaging. Further testing showed he could prevent this if he added green leaves or liver to their diet. Something in these foods helped the chicken's blood to coagulate, but did not match up with any of the other known vitamins.
He called his new coagulation nutrient vitamin K from the German Koagulations-Vitamin. Dam would earn half the 1943 Nobel Prize in Medicine for this discovery. Find out what else occurred on this day in science history
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