In the early 20th century Dr. Weston Price attempted to solve the riddle of the terrible dental health he found in his patients in Cleveland by traveling to other non-western “primitive” societies looking for an answer. What he found was many societies with remarkable levels of dental health, people with few cavities, and straight teeth because they had wide handsome jaw lines. At the time he published his results both in peer reviewed journals, and later in his book Nutrition and Physical Degeneration. While he was able to identify which foods it was found in, he never did discover the substance that he called “Activator X”, which made the difference.
In 2008 the Weston Price Foundation published a lengthy report by Chris Masterjohn solving the mystery. It identifies vitamin K2 as Activator X, which he says is important for mineral utilization, proper growth, brain functions, and the prevention of dental carries and heart disease. In modern society we are deficient in it because, while our bodies do convert the vitamin K1 in vitamin pills into K2, they do it inefficiently. While in nature the best sources of K2 are grass fed animal fats and fermented foods, our meat comes from grain fed animals, so it contains little K2.
Stephan Guyenet at his Whole Health Source blog writes about K2, and cites a study which looked at heart attack risk in Dutch men that concluded that those getting the most K2 in their diets had a 51% lower heart mortality. He also points out that Thorne Research makes a convenient K2 supplement in liquid form. Also, this site about K2 provides information concerning how much a person should take.