​​Vitamin K is a compound that is crucial for blood clotting. | The Nobel Prize

​​Vitamin K is a compound that is crucial for blood clotting.

Nobel Laureate Edward Doisy, was the first person to produce it in a pure form. By studying different analogues he established the distinction between vitamin K1 (shown) which was isolated from alfalfa, and vitamin K2, isolated from fish meal. His work became especially important in treating bleeding among small children.