Preferred Nutrition K2 is in the form of menaquinone-7 (MK-7),
an advanced, fat-soluble form of vitamin K that serves multiple
functions in the body. The K family consists of a trio of vitamins: K1
(phylloquinone), naturally occurring in leafy green vegetables and plant
oils; K2 (mena-quinone) present in butter, cows liver, eggs, certain
cheeses and natto, a fermented soybean food; and K3, a synthetic form of
the vitamin. K3 has been shown to have toxic effects on the liver and
K1 doesn’t have adequate benefits for calcium metabolism to dramatically
improve osteoporosis or atherosclerosis. Only K2 in the form of MK-7
has been shown to offer 24-hour protection from a single daily dose.
Other commercially available subtypes of K2, such as MK-4, only last
four to six hours in the body and are required in much larger dosages to
Vitamin K1 is easy to obtain from green leafy
vegetables. The bacteria in our intestines will convert some of that to
K2, but not enough to prevent or treat atherosclerosis and osteoporosis.
K2 is found in the diet in natto, a fermented soybean food popular in
Japan, as well as in butter, meat, egg yolks, and organ meats from
animals that are fed grass instead of grain. As grass-fed animal
products are rare nowadays and a taste for natto is difficult to acquire
for most Westerners, a vitamin K2 supplement is the best way to ensure
you are getting an optimal daily dose of this important nutrient.