Though largely unknown, vitamin K is critical for our health. It is needed for the normal clotting of blood and for the formation and maintenance of healthy bones. Although vitamin K2— also called menaquinone—is naturally produced by some of our intestinal bacteria, only a limited amount of this essential vitamin is stored in our bodies. A lack of this vitamin, which can be caused by a poor diet and the regular use of certain drugs such as antibiotics, is not uncommon. Now, a new supplemental form of vitamin K, specifically vitamin K2—menaquinone-7 (MK-7)—is becoming more widely available to health consumers. It is showing great promise as a natural treatment for heart disease and bone loss. Available in soy products and as a nutritional supplement, MK-7 is clinically proven to be safe and effective. It may also be helpful for lowering cholesterol levels, preventing Alzheimer's disease, and treating some forms of cancer. And MK-7 is a powerful antioxidant without side effects.