Vitamin K is a nutrient that is essential for blood clotting, which stops wounds from continuously bleeding so they can heal, and the formation of healthy bones. It is a fat-soluble vitamin, which means it is stored in the body’s fat tissues and liver.
There are two main forms of vitamin K: vitamin K1 (phylloquinone) and vitamin K2 (menaquinones).
Vitamin K1 is found primarily in leafy green vegetables, such as kale, spinach, and broccoli, while vitamin K2 is found in small amounts in meat, cheese, and eggs, and synthesized by gut bacteria in humans.
The main function of vitamin K is for blood clotting and the building of bones
When you are injured and you start bleeding, platelets (a type of blood cell) will begin to clump together at the site of the injury to form a clot.
Vitamin K is essential for the production of clotting factors, which are proteins that work together to form the clot.
Another important role of vitamin K is in maintaining strong bones. Vitamin K helps to regulate the activity of certain bone-building cells called osteoblasts, and also helps to direct calcium into the bones where it is needed.
Adequate vitamin K intake is associated with a lower risk of bone fractures and osteoporosis in older adults.
A deficiency in vitamin K can lead to a bleeding disorder called vitamin K deficiency bleeding (VKDB), which can cause heavy bruising, nosebleeds, and internal bleeding.
The recommended daily intake of vitamin K depends on age and sex, but the average adult needs between 90-120mcg per day. Good food sources include leafy green vegetables, broccoli, cauliflower, prunes, and avocados.
Some people may need to take a vitamin K supplement if they have a medical condition that affects the absorption of fat.