Vitamin K1 is the form of vitamin K found in plants. Leafy greens like spinach, kale, and broccoli supply it. The body uses it mainly to make proteins that control blood clotting, a process called coagulation. For best absorption, take it with a meal that contains some fat.
People often take Vitamin K1 to maintain normal clotting function. It is sometimes used before certain medical procedures or when someone does not get enough from food. Unlike Vitamin K2, K1 has a short half-life inside the body and heads mostly to the liver instead of bones or blood vessels.
Choose this form for coagulation support. Vitamin K2 is the form typically used for bone or arterial health.