Vitamin K2

The Nobel Prize in Physiology or Medicine 1943 was divided equally between Henrik Carl Peter Dam for his discovery of vitamin K and Edward Adelbert Doisy for his discovery of the chemical nature of vitamin K. Vitamin K2 seems to define where calcium should and shouldn't go in the body.  You need calcium to go to your bones and teeth and not to calcify the arteries (arterial plaque).

In nature, vitamin K is found in two forms: vitamin K1 (phylloquinone) in leafy, green vegetables, and vitamin K2 (menaquinone) in organ meats, egg yolks, dairy products and fermented foods. Vitamin K1 is required by the human liver to manufacture blood-clotting proteins. All animals and humans convert vitamin K1 into vitamin K2 MK-4 using gut bacteria, so it is incredibly important to have a healthy gut.


Osteocalcin is a protein hormone found in bone and teeth. Its synthesis is vitamin K2 dependent. Osteocalcin is released by osteoblasts (cells that make bone) and binds with the bone matrix. Studies conclude that a lack of vitamin K2 leads to age-related bone loss. Osteocalcin was the first protein to be identified as bone specific. Osteocalcin also acts like a hormone on many tissues to improve insulin sensitivity and blood glucose.

  • Vitamin K2 is critical in pregnancy.
  • Vitamin K2 is critical in sperm generation.
  • Vitamin K2 is promotes testosterone creation. In a Japanese rat study, Vitamin K2 yielded more than 70% increase in plasma testosterone levels, and an even bigger increase was seen inside the testes (nearly 90%). K2 works by stimulating testosterone production directly inside the testes.
  • K2 works in partnership with Vitamin A and D. Arterial plaquing it higher in the winter than the summer, because of vitamin D production in sunlight.
  • The pancreas also contains Osteocalcin. Insulin and blood sugar levels have been known to significantly drop with greater K2 concentrations.
  • Trans fats destroy vitamin K2.
  • Brain health. A vast majority of the vitamin K found in the human brain is vitamin K2. Furthermore, vitamin K2 is specifically concentrated to be higher in myelinated regions, while vitamin K1 is more randomly distributed.  Vitamin K2 correlates with lipids in the brain called sulfatides, and the decline of both is associated with age-related neurological degeneration.  Sulfatide levels in early Alzheimer’s patients are up to 93 percent lower than in healthy patients.
  • Preventing cancer. Dietary intake of vitamin K2 was inversely associated with overall cancer risk in men but not women. Specifically, both prostate (male only) and lung cancers were reduced in those who consumed the highest levels of vitamin K2. When these two cancer types were removed from the analysis, vitamin K2 intake still correlated with lower overall cancer risk. Anticarcinogenic effects of vitamin K2 have been repeatedly demonstrated in cancer cell lines and are often attributed to vitamin k2's ability to regulate gene expression.
  • Our kidneys have high concentrations of vitamin K2, which is used to activate MGP (Matrix gla protein) to remove calcium and prevent kidney stones from developing.
  • If you opt for a vitamin K2 supplement, make sure it's MK-7. Also remember to take it with fat since it's fat-soluble and won't be absorbed otherwise. The best way to get K2 is via food.
  • Low K2 levels are associated with more wrinkles in the skin.
  • Weak bones and arterial plaque (arterial plaque is 20% calcium) are a common symptom of vitamin K2 deficiency.If you compare the hip and bone fracture rates of African-American women with Nigerian/Ghanaian women (genetically exact), you find that US rates are 80 times higher. They also had much worse teeth. The African women are eating grass fed animals and milk products, containing high levels of K2.
  • Vitamin K2 has a hugely beneficial effect on tooth cavities.
  • A study recently published by the European Prospective Investigation into Cancer and Nutrition (EPIC) revealed that increased intake of vitamin K2 reduced the risk of prostate cancer by 35 percent.
  • Vitamin K2 supplementation has a beneficial effect on insulin resistance in older men

There is strong evidence that vitamin K2 deficiency is associated with osteoporosis, and some evidence that increasing K2 intake (from supplements and/or diet) can strengthen bones.  Vitamin K2 promotes moving excessive calcium out of the bloodstream and into the bones.  The conventional wisdom regarding osteoporosis (consume more calcium) is now being superseded by raising vitamin D levels which increases calcium absorption up to fourfold, making the diet more alkaline so that less calcium is leeched from the bones to balance blood pH.

You can also strengthen bones by doing “bone-bstressing” exercises like jumping sprinting and lifting heavy (this sends signals to the bones to become more dense).

The benefits of vitamin K2 are vast, including dental health, growth and development and healthy skin. 

Foods high in vitamin K2

  • Nattō (fermented soy MK7). Natto is the highest dietary source of vitamin K2 with a huge 850 micro grams per 100 gram serving (1000%+ of your RDA). It is widely eaten in Japan which has the highest longevity rate in the world. There is an exact Thai equivalent of Natto, it's called Thua nao. Available all over northern Thailand.
  • Foie gras has a high concentration of vitamin K2.
  • Hard cheese. French and Dutch cheeses especially. Gouda has the highest content of vitamin K2 than any other cheese with approximately 20 mcg per ounce. Brie, Jarlsberg’s and Edam are also good sources. Other aged, hard cheeses have some vitamin K2 as well. Switzerland, with its high grass fed dairy and vitamin k2 cheese consumption, has the 2nd highest longevity rate in the world.
  • Soft cheese.
  • Grass fed butter.
  • Grass-fed ghee.
  • Chicken liver & breast (free range birds).
  • Salami.
  • Ground beef (grass fed meat)
  • Grass fed eggs, especially the yolk.
  • Fermented foods.
  • Goose liver pate (Geese eat grass).
  • Duck and goose fat. There's a huge jump in vitamin K2 values in pastured duck fat. Duck fat has 3 times more vitamin K2 than ghee or egg yolks, 7 times more vitamin K2 than butter or cream, and 13 times more than cheese or chicken liver.
  • Emu oil. Emu oil contains more than 50 times more vitamin K2 than chicken liver or cheese, 4 times more than duck fat, more than 25 times more vitamin K2 than cream. You don't cook with emu oil, you take it as a supplement. Since it's so concentrated, you don't need to take very much.

Vitamin K2: The relationship with vitamin A and D and Magnesium

Vitamin K2, as with other vitamins and minerals, is best consumed as part of a nutrient-dense diet. Vitamin K1 and K2 are fat soluble, so they must be eaten with fat for best absorption.

Vitamins A and D are both activated by vitamin K2, allowing them to bind calcium to do their jobs. Weston A. Price in the 1940's was the first to discover the synergy between K, A and D vitamins, although at the time he referred to vitamin K2 as “Activator X,” since its true identity was unknown until 2007. He used a combination of cod liver oil, rich in vitamins A and D, and butter oil, rich in vitamin K2, to treat a variety of modern diseases. Magnesium intake is also important. Vitamins A and D induce gene expression, which is dependent on magnesium. Many people are deficient in magnesium due to a diet of processed foods.

Food Sources of Vitamin K1 (Phylloquinone, except as Indicated)

Food Micrograms
(mcg) per
Natto, 3 ounces (as MK-7, vitamin K2) 850 1,062
Collards, frozen, boiled, ½ cup 530 662
Turnip greens, frozen, boiled ½ cup 426 532
Spinach, raw, 1 cup 145 181
Kale, raw, 1 cup 113 141
Broccoli, chopped, boiled, ½ cup 110 138
Soybeans, roasted, ½ cup 43 54
Carrot juice, ¾ cup 28 34
Soybean oil, 1 tablespoon 25 31
Edamame, frozen, prepared, ½ cup 21 26
Pumpkin, canned, ½ cup 20 25
Pomegranate juice, ¾ cup 19 24
Okra, raw, ½ cup 16 20
Salad dressing, Caesar, 1 tablespoon 15 19
Pine nuts, dried, 1 ounce 15 19
Blueberries, raw, ½ cup 14 18
Iceberg lettuce, raw, 1 cup 14 18
Chicken, breast, rotisserie, 3 ounces (as MK-4) 13 17
Grapes, ½ cup 11 14
Vegetable juice cocktail, ¾ cup 10 13
Canola oil, 1 tablespoon 10 13
Cashews, dry roasted, 1 ounce 10 13
Carrots, raw, 1 medium 8 10
Olive oil, 1 tablespoon 8 10
Ground beef, broiled, 3 ounces (as MK-4) 6 8
Figs, dried, ¼ cup 6 8
Chicken liver, braised, 3 ounces (as MK-4) 6 8
Ham, roasted or pan-broiled, 3 ounces (as MK-4) 4 5
Cheddar cheese, 1½ ounces (as MK-4) 4 5
Mixed nuts, dry roasted, 1 ounce 4 5
Egg, hard boiled, 1 large (as MK-4) 4 5
Mozzarella cheese, 1½ ounces (as MK-4) 2 3
Milk, 2%, 1 cup (as MK-4) 1 1
Salmon, sockeye, cooked, 3 ounces (as MK-4) 0.3 0
Shrimp, cooked, 3 ounces (as MK-4) 0.3 0

*DV = Daily Value.