vitamin k2 listIn 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.

Vitamin K2 is fascinating, because it works as a catalyst for vitamin A and D specifically, and is found in abundance in traditional diets.  But we didn’t know what vitamin K2 even was until Dr. Price discovered it’s presence in traditional diets.  Weston A. Price used to call vitamin K2 the “activator X” before it was properly named. From Vitamin K2, menatetrenone (MK-4):

The synergism Weston Price observed between vitamins A, D and K2 now has a solid mechanism. In a nutshell, vitamins A and D signal the production of some very important proteins, and K2 is required to activate them once they are made. Many of these proteins are involved in mineral metabolism, thus the effects Price saw in his experiments and observations in non-industrialized cultures. For example, osteocalcin is a protein that organizes calcium and phosphorus deposition in the bones and teeth. It’s produced by cells in response to vitamins A and D, but requires K2 to perform its function. This suggests that the effects of vitamin D on bone health could be amplified greatly if it were administered along with K2. By itself, K2 is already highly protective against fractures in the elderly. It works out perfectly, since K2 also protects against vitamin D toxicity.

I get particularly geeked out when I read this quote, because I look at how perfect it is that these vitamins balance each other out, work synergistically, and are found together in many foods.  It’s also the reason I buy the fermented cod liver oil and high vitamin butter oil blend on my resource page.  The two together work for proper absorption and vibrant health.  How cool is that?! But Where Does Vitamin K2 Come From? I have mentioned vitamin K2 before here on Our Nourishing Roots, usually when I make something with a lot of butter.  Or something using a natural fermentation process.  You know, like ghee or sauerkraut. Vitamin K2 is produced by animals like cows and goats eating rapidly growing green grass.  It makes their milkfat special, full of this activator vitamin that is meant to be consumed by humans as a part of bone and teeth health, among other things. Fascinatingly, vitamin K2 is also abundant in fermented foods.  The fermentation process encourages the making of vitamin K2.  In particular, natto (fermented soybeans) is very rich in vitamin K2.  You can buy natto starters here. You might think that our bodies would be able to convert dietary vitamin K1 into vitamin K2, but that is not the case.  Vitamin K1 is not easily converted by our bodies, which is likely the reason we have seen traditional diet after traditional diet incorporate sacred foods that happen to be vitamin K2-rich. From Vitamin K: The Missing Nutrient:

However, although animals can convert vitamin K1 to vitamin K2, a significant amount of evidence suggests that humans require preformed K2 in the diet to obtain and maintain optimal health. The strongest indication that humans require preformed vitamin K2 in the diet is that epidemiological and intervention studies both show its superiority over K1. Intake of K2 is inversely associated with heart disease in humans while intake of K1 is not…and vitamin K2 is at least three times more effective than vitamin K1 at activating proteins related to skeletal metabolism.

What Foods Contain Vitamin K2? Foods with high vitamin K2 levels include traditional fermented superfoods like natto and grass-fed butter and cheeses.  Specifically, you should try to eat the following foods to get more vitamin K2 into your diet:

  • high vitamin butter oil
  • hard cheeses
  • soft cheeses
  • egg yolks
  • chicken liver
  • natto
  • fermented foods
  • grass-fed beef
  • pastured chicken