THORNE Vitamin D3 1,000 IU delivers essential support for healthy bones and teeth, immune function, cardiovascular health, and muscle performance. With optimal absorption as cholecalciferol, this Vitamin D3 supplement helps maximize calcium uptake and natural vitamin D production, especially for indoor workers or limited sun exposure. Gluten-, dairy-, and soy-free. Third-party tested for purity and safety. Trusted by champions and health-care practitioners.

• Vitamin D3 Benefits: Supports healthy teeth and bones by enhancing the absorption of calcium; supports immune function and cardiovascular health*
• Optimal Absorption: Vitamin D3 (as cholecalciferol) is more potent and better absorbed than vitamin D2 (or ergocalciferol); research shows vitamin D3 is more effective at raising overall vitamin D levels*
• Essential Vitamin D: Optimizes performance, muscle strength and mass, and cellular repair, especially for those who work indoors or lack adequate sun exposure to support the body's natural vitamin D production*
• 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)