THORNE Vitamin D3 Supplement - 1000 IU - 90 Softgels

Understanding Vitamin D3 and D2

Vitamin D occurs in two main forms: D2 (ergocalciferol) from plant sources and D3 (cholecalciferol), which is naturally produced in human skin upon exposure to sunlight and also found in animal-based sources like lanolin. Research indicates that D3 is more effective at raising and maintaining blood levels of vitamin D. THORNE uses the superior D3 form to ensure optimal bioavailability.*

Key Benefits of THORNE Vitamin D3

THORNE Vitamin D3 provides 1,000 IU of vitamin D3 per soft gel capsule, which contributes to several aspects of health.* The following claims are authorised by the European Food Safety Authority (EFSA):

• Normal absorption and utilisation of calcium and phosphorus: Vitamin D3 enhances the absorption of these minerals, supporting overall mineral balance.*
• Maintenance of normal bones: Adequate vitamin D levels help maintain strong, healthy bones.*
• Maintenance of normal teeth: Vitamin D contributes to dental health by supporting mineralisation.*
• Normal muscle function: Vitamin D plays a role in muscle performance and recovery, making it a favourite amongst athletes.*
• Normal function of the immune system: Adequate vitamin D levels support a healthy immune response, keeping your defences ready.*

Each soft gel capsule delivers 1,000 IU of pure vitamin D3 in a base of medium-chain triglycerides (MCT oil) for optimal absorption. This fat-soluble vitamin is best taken with a meal containing fat to maximise uptake.

Who Should Consider Supplementing with Vitamin D3?

Certain groups are at higher risk of vitamin D deficiency. If you spend much of your time indoors, live in northern regions like Scotland, have darker skin, or are over 60, you may benefit from supplementation. Additionally, those following a vegetarian or vegan diet should note that THORNE Vitamin D3 is derived from lanolin (sheep's wool) and is not suitable for vegans. Always consult your health care provider to determine your optimal dosage based on blood tests.

How Much Vitamin D3 Do You Need?

The recommended dietary allowance (RDA) for vitamin D in the UK is 400 IU (10 micrograms) daily for most adults, whilst many experts suggest higher intakes for maintenance, especially for those with deficiency. THORNE's 1,000 IU per serving provides a moderate yet effective amount for most adults. The tolerable upper intake level is 4,000 IU per day, so this product fits well within safe boundaries. For personalized advice, work with a health care professional to check your levels.

What Sets THORNE Vitamin D3 Apart?

THORNE is a brand trusted by over 100 professional sports teams and is the number one most recommended clinical brand by consumers and health care practitioners, according to a 2026 independent survey. This product is third-party tested to verify potency and purity. It is also free from gluten, dairy, and soya, making it suitable for those with sensitivities. The softgels are easy to swallow and individually sealed for freshness.

Safety and Quality Assurance

Vitamin D3 is generally safe when taken as directed. However, excessive intake can lead to toxicity, so follow the recommended dosage. THORNE adheres to strict quality control standards, and the product is manufactured in an NSF-certified facility. Third-party certification provides added confidence that the label matches the contents.

Why Take a Vitamin D3 Supplement?

Vitamin D is often called the "sunshine vitamin" because your skin produces it when exposed to sunlight. However, many people in the UK have insufficient levels due to indoor lifestyles, sunscreen uses, and the northern latitude. Supplementing with vitamin D3 (cholecalciferol) is an effective way to maintain healthy levels year-round. THORNE Vitamin D3 provides 1,000 IU per soft gel capsule, which helps support overall wellness.*

*These statements have not been evaluated by the Medicines and Health care products Regulatory Agency (MHRA). This product is not intended to diagnose, treat, or prevent any disease.