Animal products serve as the best food sources for vitamin K2. Common foods particularly high in vitamin K2 include chicken, ham, salami, beef and bacon. While not as commonly consumed, organ meats, such as liver, have the highest levels of vitamin K2.
Some animals can synthesize vitamin K2 from a nutrient found in grass. For this reason, the optimal animal-product sources of K2 are animals raised with grass as a key component of their diets.
However, taking in a healthy level of K2 does not have to involve meat. Some dairy products such as egg yolks serve as a source of the vitamin as well, though egg whites do not. Most K2-rich dairy products also have high levels of fat. Whole milk, hard cheeses made from whole milk, fermented milk, cream and butter can also be reasonable sources of vitamin K2.
Vegan options for keeping up a healthy level of K2 also exist. Natto, a nutritious dietary option from Japan made from fermented soybeans and often eaten with cooked rice, contains the vitamin. More common sources of vitamin K2 that do not contain animal products include peanut butter and cooking oil.
As with other vitamins, supplements provide an alternative means to get enough vitamin K2. However, eating foods rich in K2 remains the ideal way to maintain healthy levels of the vitamin.