Because I can't eat soy and most forms of K2 are derived from soy I am trying Mercola's vegetable ferment cultures which are supposed to be formulated to maximize k2. I have my first batch of sauerkraut using this culture fermenting now. Of course there is no way to know how much k2 I will get from the sauerkraut but I'm thinking it can't hurt. Before this I just used salt to ferment vegetables.