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Vitamin K Content Of Foods

Vitamin K1 is effective at supporting healthy insulin levels... and vitamin K2 plays a vital role in ensuring that calcium stays in the bones and out of the arteries.

Vitamin K2 may also protect the heart and inhibit cancer. Addressing the vitamin K content of foods is important when designing a diet for healthy bones as well as for a healthy heart.

An effective osteoporosis prevention program will include foods that containing vitamin K2 as well as vitamin K1. But that is not as easy as it sounds... unless you live in southern France.

VITAMIN K1 CONTENT OF FOODS

Dark leafy green vegetables are rich in vitamin K1... some of which is transformed into vitamin K2 in the intestine. A cup of dark leafy greens can provide more than the recommended daily requirement of 90-120 mcg a day as may be seen in the following nutrition list provided by the United States Department of Agriculture (USDA) Food and Nutrition Center. Although the recommended intake for vitamin K may be sufficient to ensure blood clotting, there is still no agreement on the amount of vitamin K should be included in the ideal osteoporosis prevention diet. The Framingham Heart Study (of more than 800 elderly men and women for seven years) found that participants with dietary vitamin K intake of 250 mcg/day had a 65% lower risk of hip fracture than those with dietary vitamin K intakes of 50 mcg/day or less.The following lists shows the amount of vitamin K1 in one cup of cooked vegetables:

  • Kale: 1062 mcg
  • Spinach: 888 mcg
  • Collards: 836 mcg
  • Beet Greens: 697 mcg
  • Swiss Chard: 573 mcg
  • Broccoli: 220 mcg
  • Brussel Sprouts: 218 mcg
  • Cabbage: 163 mcg

Chinese cabbage (also known as pak-choi, bok choy or Korean kim chi) contains only 57.8 mcg in a cup of vegetables but when combined with tofu it provides an outstanding balance of calcium, magnesium and vitamin K for a very bone healthy meal. It is important to note that spinach, swiss chard and beet greens have a high content of oxalates which tend to bind calcium and prevent its absorption. This does not mean that they should be avoided as they are excellent sources of vitamin K but it may be better to take a calcium supplement when these leafy greens are not part of your meal.

VITAMIN K2 CONTENT OF FOODS

Vitamin K2 is really a compound that includes several forms of the vitamin. Research has shown that foods containing 45 mcg of vitamin K2 in the form of MK-4 and MK-7 are of most value when creating an osteoporosis prevention or treatment program. The best known food containing vitamin K2 in the form of MK-7 is natto... a fermented soy product that is popular in Japan. Natto contains 1103 mcg of MK-7 in 100 grams of fermented soy.Vitamin K2 in the form of MK-4 is found primarily in products from animals that have fed on fast growing grass, which is no longer common in North America except perhaps on organic farms. The richest source is fois gras (goose liver paste) that is so loved by gourmets and is a common part of meals in the Perigord region of southern France. The amount of vitamin K2 (MK-4) in 100 grams/3.53 oz is reported as follows:

  • Fois Gras: 369 mcg
  • Egg Yolk (Netherlands): 32 mcg
  • Goose leg: 31 mcg
  • Egg Yolk (US): 15.5 mcg
  • Butter: 15 mcg
  • Chicken liver: 14 mcg
  • Chicken breast: 8.9 mcg
  • Chicken leg: 8.5 mcg
  • Ground beef: 8.1 mcg
  • Bacon: 5.6 mcg
  • Calf liver: 5 mcg
  • Whole milk: 1 mcg
  • Milk 2%: .5 mcg

The above list of foods gives us an idea of how difficult it is to add enough of this important vitamin to a North American diet. Research has shown benefits from vitamin K2 intake as low as 32.7 mcg per day (which provided protection against cardiac disease in a Rotterdam study) to as high as 45 mg a per day, which is the prescription dose of MK-4 used to treat osteoporosis.

Note that the United States Department of Agriculture (USDA) Food and Nutrition Center does not provide data on foods containing vitamin K2. The nutrient data listed above was gathered from the following two studies:

  • Elder SJ, Haytowitz DB, Howe J, Peterson JW, Booth SL. Vitamin K Contents of Meat, Dairy, and Fast Food in the U.S. Diet. J Agric Food Chem. 2006; 54: 463-467.
  • Schurgers LJ, Vermeer C. Determination of Phylloquinone and Menaquinones in Food. Haemostasis. 2000; 30: 298-307.

To learn how the vitamin K content of foods supports other natural remedies... visit Osteoporosis Treatment Guidelines