Why Thorne? We've proven better is possible. Tested and trusted since 1984, Thorne applies scientific rigor, clinical expertise, and uncompromising standards to every product – all to provide unparalleled solutions for your health.Our supplements go through four rounds of testing, ingredient validation, and trusted third-party certifications. Decades of clinical experience drive product development, translating research into bioavailable formulations. Our “No List” guides this work, identifying 33 ingredient categories of fillers, binders, and additives we refuse to use in our supplements.With Thorne, you can build a routine that actually works for you based on personalized recommendations backed by scientific data. Experience superior results guided by our researchers, physicians, athletes, and partners committed to scientific wellness.Headquartered in Summerville, South Carolina, Thorne manufactures supplements in the USA using globally sourced ingredients. Thorne maintains internationally recognized certifications that demonstrate our commitment to excellence, including an exemplary record of compliance with the FDA’s current Good Manufacturing Practices (cGMP); certification by NSF, the “gold standard” for quality for dietary supplements; and an A rating from Australia’s TGA, the toughest regulatory agency in the world.

• Bone & Muscle Health: Both vitamin D and vitamin K2 support 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*
• Self-Dispensing Top: To provide accurate and individualized dosing, the bottle includes a self-dispensing top that meters individual drops
• 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 trusted by 100+ professional sports teams and the #1 most recommended clinical brand by consumers and health-care practitioners (Based on a 2026 independent survey of US supplement consumers and health-care practitioners)
• Take 2 drops one to three times daily or as recommended by a health-care practitioner. Invert bottle to dispense individual drops. May be added to food or mixed in beverages. Servings Per Container: 600