Where can I find information about the content of vitamin K in food?

Facts about vitamin K (1)

  • Vitamin K is a fat-soluble vitamin occurring in two forms in foods. Mostly as vitamin K1 (phylloquinone), and as vitamin K2 (sum of menaquinones) in a smaller amount in some foods.
  • The K1-form occurs in plants and is made by photosynthesis
  • K2 is produced by bacteria in the intestine in animals.
  • Both forms of vitamin K also occur in animal products, but in small amounts.
  • In animal products, liver and some cheeses contain the largest amount of K2
  • Vitamin K2 is also produced by fermentation of vegetables. A fermented soybean preparation (natto) is particularly rich in vitamin K.

The absorption of vitamin K increases when fat is digested (in moderate amounts), because vitamin K is fat-soluble. Naturally deficiency of vitamin K rarely occurs, because some vitamin K2 may be produced by intestinal bacteria in humans. Reduced digesting or other problems in the intestine, such as reduced fat absorption, may cause deficiency.

Vitamin K is necessary in coagulation of blood in the body. In addition, the vitamin is an important part of the calcium-binding proteins, and it is important in the production of bone mass, working closely with vitamin D. People treated with anticoagulants should have a stable intake of vitamin K.

Vitamin K in foods

  • Good sources of vitamin K include leafy green vegetables, such as broccoli and spinach, products of vegetable oil (particularly rapeseed-, soya- and olive oil). Some algae have a high content of vitamin K  (2).
  • Vitamin K is quite stable during heat treatment, but it is sensitive to light. Thus, oils should be kept in a dark and preferably cold place (to prevent rancidity of the fat). Dried food has a larger concentration of vitamin K, but the concentration will change during dilution in water.

Sources of information

  • Vitamin K is for the present not included in the Food Composition Table.
  • Vitamin K (K1 and/or K2) is listed in some foreign food composition tables. In order to evaluate the quality of the sources of data, it is recommended to read the background texts to receive information about what type of the nutrient the tables have included, and where the values come from (reference/source), for instance from analyses, calculated values, or borrowed from another food composition table.

Food Composition Tables with vitamin K

References

  1. Nordic Nutrition Recommendations, (Nordic Council of Ministers 2004)
  2. Becker W, Staffas A, Abbasi H. (1998). K-vitamin livsmedel. Resultat från Livsmedelsverkets analyser 1996-97 samt litteraturdata. SLV-Rapport 4/98