Forms of vitamin K
There is more than one form of vitamin K. The most used are: K1, K2 MK4 and K2 MK7.
Vitamin K1 (phylloquinone, phytomenadione, or phytonadione) is plant derived. It is used in our bodies as a clotting factor. It is easily optained from food and is recycled by the body. Deficiencies are rare.
The vitamin K2’s that are usually meant when talking about bone strength and other things associated with calcium are K2 MK4 and K2 MK7.
Vitamin K2 MK4 comes from animals in its natural form. In supplements it is synthetic, but exactly the same as the natural molecule. It has a short half life (meaning it doesn’t stay in the body for very long) and needs to be taken 3 times daily. K2 MK4 is called menatetrenone and also menaquinone-4.
Vitamin K2 MK7 comes from fermentation and is found in hard cheeses for instance. K2 MK7 can be taken once a day because it has a long half life. K2 MK7 is called menaquinone-7.
Both K2 MK4 and K2 MK7 can be used by our body to help shuttle calcium to the right places. K2 MK7 stays in the body longer then K2 MK4 and is a lot cheaper too. This is why people often use K2 MK7 over K2 MK4. But Weston Price did his extended research using natural K2 MK4 from whole foods.
Often the term “vitamin K” is used for either K1 or K2 MK4 or K2 MK7. But K1 and K2 have very different roles in the body. Also, a lot of sites do not distinguish between K2 MK4 and K2 MK7. But I haven’t found any studies yet to back this up. Also, the dosages for the two are very different.
http://www.lef.org/magazine/mag2008/mar2008_Protecting-Bone-And-Arterial-Health-With-Vitamin-K2_01.htm A two-year Japanese study found that vitamin K2 (MK-4) reduced the incidence of vertebral (spine) fractures by 52% in 120 patients with osteoporosis, compared with patients who did not receive this nutrient.
Dr. Kate Rhéaume-Bleue: Vitamin K2 and the Calcium Paradox
How much to take
- This has some not-so-good fillers, but is a high dosage and cheap http://www.ebay.nl/itm/VITAMIN-K2-500mcg-60-120-360-Tablets-as-Menaquinone-Mk7-Bone-Health-/251509429596?pt=UK_Health_Beauty_Vitamins_Supplements&var&hash=item3a8f21555c&_uhb=1