Vitamin K—a group of fat soluble compounds known as naphthoquinones, including vitamins K, K1, K2, and K3—is best known for its healthy blood clotting ability. One example of healthy blood clotting is when someone gets a simple cut and the bleeding stops via sufficient blood clotting to close the wound. Vitamin K helps keep blood clotting at just the right levels—not too little and not too much. Two signs that may indicate a deficiency of vitamin K are excess bruising or nose bleeds, and those most at risk for a vitamin K deficiency include those with alcohol dependency and people with chronic malnutrition.
Vitamin K may also help prevent kidney stones, help prevent hardening of the arteries, help prevent postmenopausal bone loss, help protect bones from fracture, and provide possible protection against liver and prostate cancer.
Dietary vitamin K is known as phylloquinone, or K1. There are many foods that provide excellent, very good and good sources of vitamin K: asparagus, basil, bell peppers, blueberries, broccoli, Brussels sprouts, cabbage, cauliflower, celery, chili powder, collard greens, cucumber, curry, grapes, green beans, kale, leeks, mustard greens, oregano, parsley, peas, spinach, spring onions, Swiss chard, thyme, tomatoes, and turnip greens.