What is Vitamin K? In foods, Vitamin K1 (Phytonadione) is typically found in leafy greens like collards, kale, and spinach, while Vitamin K2 (Menaquinone -4 and Menaquinone-7 is) found in Japanese natto, egg yolks, and cheese curds. Most Vitamin K supplements are in K 2 form. Nature's Truth Vitamin K is a full spectrum complex that features K1, two forms of K-2, MK-4, and MK-7. Vitamin K2 is sometimes combined with D3.