Vitamin K exists as K1 (phylloquinone) from leafy greens and K2 (menaquinones) from fermented foods and animal products. It helps blood clot and affects bone metabolism.
Vitamin K activates proteins that steer calcium into bones and away from arteries. Many people take it for bone density and heart health, often alongside vitamin D and calcium.
Take vitamin K with a meal that contains some fat, since it is fat-soluble. Doses depend on the form. K1 and K2 (and the specific menaquinone) need different amounts, so follow label directions or ask a professional.
Caution: Vitamin K can interfere with blood thinners like warfarin. If you take anticoagulants, talk to your doctor before taking it.