doisy

Vitamin K

Today is the birthday of Edward Adelbert Doisy, an American scientist who won the Nobel Prize in Physiology or Medicine in 1943 for his work (along with Danish scientist Henrik Dam) in the discovery of Vitamin K.  After earning his Ph.d from Harvard, Doisy would spend most of his career at St. Louis University, where he devised the cholesterol deprivation experiments that led to the isolation and identification of Vitamin K.  Vitamin K was given its name after Doisy and Dam first published their findings in a German scientific journal, which referred to the substance by the first letter of its German designation,  Koagulationsvitamin, the K indicating (in German) the coagulation qualities of the new substance.  

The word vitamin was only coined a few decades earlier in 1912 by Polish chemist Casimir Funk as a combination of the Latin word vita for life and amine because vitamins were thought to contain amino acids.  By 1920 the -e- was removed from the end to reflect the new science of the day that recognized that vitamins were not in fact related to amino acids.  Today a vitamin is defined as an organic compound required for proper nutrition by an organism that cannot be synthesized by the organism.  Since their discovery and classification the list of vitamins has changed over time, notably the arrangement of compounds into the B-complex family.

Today 13 vitamins are recognized:  Vitamins A, B1, C, B2, D, E, B12, K1, B5, B7, B6, B3, B9.

Image of Vitamin K1 created with CheMagic.