THORNE Vitamin D3 Supplement, 1,000 IU, 90 Capsules for Bone & Immune Support

THORNE Vitamin D-1,000 is a vitamin D3 supplement designed to support healthy bones, teeth, immune function, and cardiovascular health, with 1,000 IU per capsule and 90 capsules per container.

• Vitamin D3 as cholecalciferol — supports calcium absorption for healthy teeth and bones.
• Third-party tested and certified — verifies label accuracy and checks for unsafe contaminant levels.
• More effective at raising vitamin D levels than D2, according to research cited for the product.
• Supports muscle strength and mass, cellular repair, and performance.
• Trusted by more than 100 professional sports teams.
• Ranked the #1 most recommended clinical brand by consumers and health-care practitioners in a 2026 independent US survey.

Vitamin D is made naturally by the body in response to sun exposure. THORNE Vitamin D-1,000 offers a capsule-based way to add vitamin D3 to a supplement routine, including for people who work indoors or do not get adequate sun exposure. Its stated support spans bone and tooth health, immune function, cardiovascular health, and muscle function.

What is THORNE Vitamin D-1,000 designed to support?

It is formulated to support healthy teeth and bones, immune function, and cardiovascular health. Vitamin D3 helps the body absorb calcium, while vitamin D also plays a role in muscle strength and mass, cellular repair, and performance.

• Each capsule provides 1,000 IU of vitamin D3.
• The formula uses cholecalciferol, the D3 form of vitamin D.

Why choose vitamin D3 instead of D2?

THORNE Vitamin D-1,000 contains D3, which is more potent and better absorbed than vitamin D2, also known as ergocalciferol. Research cited for the product indicates that D3 is more effective at raising overall vitamin D levels.

• D3 is provided as cholecalciferol.
• D2 is the alternative form referred to as ergocalciferol.

Who may find this vitamin D3 supplement useful?

It is especially relevant for people who work indoors or lack adequate sun exposure to support the body’s natural vitamin D production. Vitamin D supports functions including calcium absorption, muscle strength and mass, and cellular repair.

• Capsule format for adding vitamin D3 to a supplement routine.
• The container includes 90 capsules.

How is THORNE Vitamin D-1,000 tested?

The product is third-party tested and certified to verify that its contents match the label and to confirm it contains no unsafe levels of contaminants. Thorne is trusted by more than 100 professional sports teams; a 2026 independent survey of US supplement consumers and health-care practitioners ranked it the #1 most recommended clinical brand.

• Third-party certification covers label accuracy and contaminant checks.
• The brand recommendation ranking is based on a 2026 independent US survey.

THORNE Vitamin D-1,000 is suited to adults looking to supplement vitamin D3, particularly those with limited sun exposure who want support for calcium absorption, bones, teeth, and other vitamin D-related functions. It provides 1,000 IU of D3 per capsule in a 90-capsule supply.

Ingredients

One Capsule Contains: Vitamin D (as Vitamin D3) (1,000 IU) 25 mcg. Other Ingredients: Microcrystalline Cellulose, Hypromellose (derived from cellulose) capsule, Leucine, Silicon Dioxide, Vitamin E (d-Alpha Tocopheryl).