Vitamin K is a fat-soluble vitamin that helps create strong bones, makes proteins important in blood clotting, and promotes good blood flow. Low levels of vitamin K can lead to abnormal blood flow. Vitamin K is a group of compounds, the most important ones are vitamins K-1 and K-2. Vitamin K-1 is obtained from leafy greens like broccoli, collard greens, kale, and spinach. Vitamin K-2 is obtained from meats, cheeses, and eggs, and it can be synthesized by bacteria.