• Vitamin K₁: Green leafy vegetables such as spinach, broccoli, Brussels sprouts, lettuce, avocado, kiwi, grapes.
• Vitamin K₂: Fermented or aged cheeses and soya products, eggs, meat, fermented vegetables (sauerkraut).

The K vitamins are a group of fat-soluble vitamins: vitamin K₁ (phylloquinone) and vitamin K₂ (menaquinone). Vitamin K₁ is found in plants and is the predominant form in food. Vitamin K₂ is found in animal-based products and fermented foods; it is also produced by the human intestinal flora (from the age of 3 months). However, the amount produced is generally insufficient to meet requirements.

Vitamin K is involved in the formation of various proteins that are needed for blood clotting and bone formation.