The History of the Discovery of Vitamin K.

Vitamin K was discovered during the 1930s when a strange haemorrhagic disorder was observed in chickens fed a cholesterol-free diet. A fat-soluble agent, present in green leafy vegetables and hog liver, was able to restore haemostasis in the chickens. The chemical structure and the physiological role of vitamin K were uncovered resulting in the Nobel Prize being awarded to Henrik Dam and Edward Doisy in 1943. The discovery of vitamin K led to a breakthrough in our understanding of the human coagulation system, where vitamin K plays a pivotal role in activating prothrombin and other coagulation factors. The prevention of vitamin K-dependent bleeding in newborns by vitamin K prophylaxis was introduced in the 1940s and is today a strong recommendation by the World Health Organization. Vitamin K also became crucial to the management of diseases with high risk of vitamin K deficiency due to malabsorption of fat. Later a new type of drug was developed, vitamin K antagonists, counteracting the physiologic effects of vitamin K for the prevention of thrombotic events. Recent research has indicated that vitamin K may have important functions beyond coagulation in extra-hepatic tissues by promoting healthy bone mineralization and preventing vascular calcification.