Article Summary In 1945, Dr. Weston Price described “a new vitamin-like activator” that played an influential role in the utilization of minerals, protection from tooth decay, growth and development, reproduction, protection against heart disease and the function of the brain.Using a chemical test, he determined that this compound—which he called Activator X—occurred in the butterfat, organs and fat of animals consuming rapidly growing green grass, and also in certain sea foods such as fish eggs.Dr. Price died before research by Russian scientists became known in the West. These scientists used the same chemical test to measure a compound similar to vitamin K.Vitamin K2 is produced by animal tissues, including the mammary glands, from vitamin K1, which occurs in rapidly growing green plants.A growing body of published research confirms Dr. Price’s discoveries, namely that vitamin K2 is important for the utilization of minerals, protects against tooth decay, supports growth and development, is involved in normal reproduction, protects against calcification of the arteries leading to heart disease, and is a major component of the brain.Vitamin K2 works synergistically with the two other “fat- soluble activators” that Price studied, vitamins A and D. Vitamins A and D signal to the cells to produce certain proteins and vitamin K then activates these proteins.Vitamin K2 plays a crucial role in the development of the facial bones, and its presence in the diets of nonindustrialized peoples explains the wide facial structure and freedom from dental deformities that Weston Price observed.