Vitamin K
Its created by the bacteria in the intestine. Its also needed for healthy blood clotting and finally it plays a role in maintaining healthy bones (prevent osteoporosis and fractures) and heart. Low levels increases the calcification of the blood vessels and thus causes atherosclerosis.Deficiencies are rare due to the bodies ability to produce it itself.

Vitamin K: Food Sources
Highest amounts are found in spinach, turnips greens, broccoli, green cabbage, tomatoes and liver.
Smaller amounts are found in egg yolk, whole wheat, fruits, cheese, ham and beef.Only time to take vitamin K would be in cases of malabsorption or medical disorders.

Toxicity
Symptoms of overdose of vitamin K are hemolytic anemia, in which the red blood cells die more quickly than the body can replace them.