Calcium absorption is essential—but it is equally important that calcium reaches the right tissues: bones and teeth. Calcium deposited in organs that do not need it can contribute to many medical problems, including arterial narrowing, heart disease, kidney stones, and heel spurs.
Vitamin K2 is a fat-soluble vitamin responsible for directing calcium to the right tissues and helping prevent calcium deposition where excess calcium is not needed.
The vitamin was discovered in the 1930s and until recently was mainly known as a clotting factor. Its importance as a calcium regulator in the body has become clearer only more recently.
The main dietary source of K2 comes from animals that feed on leafy forage. During fermentation processes in the animal’s digestive system, K2 is formed.
The link between vitamin D and vitamin K2
There is a close functional relationship between vitamins D and K2. High vitamin D intake may reduce available K2; K2 deficiency can then contribute to adverse effects associated with high vitamin D levels.
Food researcher Weston Price and the mystery of the “unknown vitamin”
In the 1930s, the well-known scientist who studied long-lived healthy populations found that groups with little dental caries consumed foods rich in vitamins A and D plus an unrecognized factor he called Activator X. Only in 2007 did it become clear that this “unknown vitamin” linked to healthy teeth was K2.
What are signs of vitamin K2 deficiency?
A tendency to accumulate plaque and calculus; prominent leg veins (the vitamin is involved with a protein that helps prevent vein formation issues in the legs); increased calcium deposition in soft tissues; arterial narrowing; and kidney stones.
Foods rich in vitamin K2?
- Animal foods—especially from animals that eat leaves/forage
- Fermented foods. Natto (fermented soy) has among the highest values
- The vitamin is produced by fermentation involving Bacillus subtilis natto
Supplements:
There are two common supplemental forms of vitamin K2: MK-4 and MK-7.
MK-7: a commonly discussed daily range is 100–400 mcg once daily (verify product labeling and clinical advice).