Bone & Muscle Health: Both vitamin D and vitamin K2 provide advanced support for bone and muscle health, as well as cardiovascular health and immune function* | Promotes Calcium Absorption: Vitamin D is necessary for calcium absorption, and vitamin K is important for directing calcium to the bones and away from the soft tissues, such as the blood vessels and kidneys* | Combo Effect: A convenient self-dispensing top provides accurate dosing of individual drops of well-tolerated vitamins D3 and K2, which offer greater support when taken together* | Third-Party Certified: This product has been third-party tested and certified to verify what's in the package matches what's on the label and to confirm it contains no unsafe levels of contaminants | Trusted: Thorne is chosen by champions and trusted by 100+ professional sports teams, a proud partner of U.S. National Teams, and the #1 recommended clinical brand by health-care practitioners (2023 Health-Care Practitioner Seller Survey)