D3-10,000 + K2™ is considered both a hormone and a vitamin, is synthesized in response to skin’s exposure to sunlight and is essential to the body’s absorption of calcium. This formula incorporates a natural vitamin K2 (as menaquinone 7) which supports enhanced utilization of calcium in the bloodstream. It is an all-transnatural menaquinone 7 with the greatest bioavailability and longest half-life in the blood.