Vitamin D3

Thorne Vitamin D3 supports strong bones, cardiovascular health, immune function, muscle strength, and a positive mood.* It’s ideal for individuals at risk of low vitamin D levels due to limited sunlight exposure or dietary challenges, as well as those looking for flexibility with a vegan and easy-to-dose liquid form of Vitamin D3. If you’re unsure whether you need vitamin D supplementation, we recommend having your vitamin D levels tested to help determine if supplementation is appropriate for you.

We test each ingredient in Vitamin D3 for identity, purity, and potency to ensure every ingredient and finished product meet our strict quality standards at the time of manufacture and up to the product’s expiration date. This includes checking for contaminants like heavy metals, pesticides, and harmful microbes. When the product carries the NSF Contents Certified mark, it means it has been third-party tested and certified according to strict standards for quality, safety, and label claims.

Vitamin D3 (cholecalciferol) is the same form of vitamin D your body naturally produces when your skin is exposed to sunlight. It helps your body absorb calcium and phosphorus to support strong bones and teeth, and it also plays an important role in immune and muscle function. Vitamin D3 is considered the preferred form for maintaining healthy vitamin D levels.*

Vitamin D3 is generally considered the preferred form of vitamin D because research shows it is more effective at raising and maintaining vitamin D levels in the blood than vitamin D2. Both forms support bone health and overall vitamin D status, but D3’s greater ability to sustain optimal levels is why it’s commonly recommended in supplements.*

Vitamin D3 and vitamin K2 work synergistically in the body. Vitamin D3 helps enhance calcium absorption and retention, while vitamin K2 helps direct that calcium into the areas where it’s needed most, and away from soft tissues. For individuals supplementing with vitamin D, adding vitamin K2 can provide complementary support for bone and cardiovascular health.* Whether you need to take both vitamins depends on a variety of individual health factors and is best discussed with your health-care provider. If you are taking blood-thinning medication, consult your health-care professional before using vitamin K-containing supplements.