Menaquinone (vitamin K2) is one of only two natural forms of vitamin K;  Phylloquinone (K1) is the other. However, Menaquinone’s bioavailability is up to 15x superior to Phylloquinone. Ours is soy-free and is naturally produced via fermentation using Bacillus subtilis natto, a probiotic microorganism cultured from natto, a Japanese superfood.