Vitamin K is an essential vitamin for blood clotting. Recent studies suggest that it may play an important role in the treatment of osteoporosis and Alzheimer’s. But its discovery dates back to the late 1920s with the investigations of a Danish biochemist: Henrik Dam.
The son of an apothecary and a school teacher, Henrik Dam was born on February 21, 1895 in Copenhagen. He studied Chemistry at the Polytechnic Institute of the same city and little by little he specialized in the area of nutrition. In 1928 he began to study cholesterol metabolism using chickens fed a fat-free diet. He observed that these animals could synthesize cholesterol, but also that some developed internal bleeding spontaneously. These were lesions similar to those found in scurvy, so he added lemon juice, rich in vitamin C, to the diet. Neither this supplement nor that of other vitamins known at the time (A and D) managed to reverse the situation.
After experimenting with a wide variety of food additives, he found that an extract of alfalfa prevented bleeding. This led Dam, in 1935, to the conclusion that alfalfa must contain something, as yet unknown, that faced bleeding and he postulated the existence of a new , fat-soluble vitamin, which he called “vitamin K”, by the Danish Koagulation .
This is how vitamin K works
Today it is known that blood clotting is the result of a series of processes that occur after an injury and culminate in the formation of a thin layer of fibrin, which is the clot itself. This comes from the precipitation of fibrinogen molecules, a protein present in the blood, after reacting with another protein, thrombin, developed, in turn, from prothrombin, a substance formed in the liver. It is now known that vitamin K is essential for the formation of prothrombin and that its deficiency leads to a lack of the protein and therefore a lack of thrombin. And as a consequence, fibrinogen could not form the fibrin necessary for blood clotting.
Henrik Dam discovered that vitamin K is not only found in the plant kingdom, but also in certain organs of animals, especially the liver. The bacteria in the intestinal tract are also capable of synthesizing it, being one of the ways to satisfy the body’s need for this vitamin. Another common route is the intake of foods rich in it such as broccoli, Brussels sprouts, pickles and asparagus.
Since the discovery of vitamin K, great efforts were made to determine its nature. Dam himself prepared, from alfalfa, an oil with a high content of the vitamin. But it was in the United States where there was an intense race to solve the enigma. In 1939, the world-renowned biochemist Edward Doisy was the first to reach the goal. Together with his collaborators, he managed to prepare two different pure K vitamins: K1 from alfalfa and K2 from fishmeal. That same year he managed to elucidate their chemical structures, turning out to be derived from naphthoquinone.
What is vitamin K for?
The exact biochemical function of vitamin K was not resolved until the late seventies, however, its discovery was of vital importance in two areas mainly: in surgical procedures and in the treatment of newborns . Before surgery, patients are given the vitamin to help blood clot and reduce the risk of death from bleeding. Newborns, on the other hand, are born with vitamin K deficiency, the production of which is induced by beneficial bacteria that exist in the environment and enter the intestinal tract of infants. Mothers are also injected with vitamin K shortly before giving birth to ensure that adequate amounts of the vitamin will be in the newborn’s system.
The discovery of vitamin K brought Dam to the forefront of the scientific world. A year later he traveled to the United States to participate in a series of conferences and during his stay Nazi Germany invaded his country and could not return. During World War II, Dam worked at the Wood Hole Marine Biology Laboratory, the University of Rochester, and the Rockefeller Institute. From Copenhagen they appointed him professor of biochemistry, a position that he could not occupy until the end of the contest. Also in this period, exactly in 1943, Dam received the Nobel Prize in Physiology or Medicine, an award shared with Doisy for his work on vitamin K research.
After the liberation of Denmark, Dam returned to continue his research and occupy different positions, such as head of the department of biochemistry at the Copenhagen Polytechnic Institute or director of the Danish Public Research Institute. During his career he published more than 100 articles, mainly on vitamin K, but also on vitamin E and cholesterol.
Currently, research is continuing on vitamin K. It appears that it is involved in calcium homeostasis, in the inhibition of calcification of the walls of blood vessels, facilitates the mineralization of bones and participates in the renewal of tissue and control of cell growth, among other numerous effects. An old protein in new perspectives.
