Thorne Vitamin D3 supplement bottle
Thorne

Vitamin D3 Review

What We Researched
1 active ingredient analyzed · 2 inactive ingredients decoded · 10 brand certifications checked · Last updated: Aug 2026
100
Product Score Excellent
98
Brand Score Excellent

Two independent scores — the product and the brand behind it, never blended into one number. See our methodology.

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Vitamin D 100 mcg
Bioavailability Excellent

Absorption Rating

  • Vitamin D Good
Other Ingredients Excellent

Fillers & Additives

  • Mixed Tocopherols
  • Medium-chain Triglycerides Oil
Efficacy Excellent

Dosage Analysis

  • Vitamin D 100 mcg Effective

Supplement Facts

Ingredient Amount % Daily Value
Vitamin D 100 mcg

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Mixed Tocopherols Safe

Prevents oxidation and rancidity in oil-based supplements.

Medium-chain Triglycerides Oil Unknown
Brand Trust Report
Thorne

Founded 1984 · New York, NY, United States · 204 products · thorne.com

Certifications

10 certifications
Nsf Certified For Sport Verified Source
Nsf Gmp Verified Source
Fda Gmp Inspections Verified Source
NSF Certified for Sport Verified
NSF Contents Certified Verified
Informed Choice Verified
Informed Sport Verified
Eurofins Certified Supplement Verified
Eurofins Clean Sport Verified
NSF Certified Verified

Transparency

4 claims
Third Party Testing Claim — Verified Source
Testing Lab Disclosure — Verified Source
In House Testing — Verified Source

Violation History

2 incidents
Recall Captomer, Captomer-2502014-06-12Source
Prop 65 Lead2013-12-13Source
Related Supplements
Frequently Asked Questions
Is Thorne Vitamin D3 a good supplement?

Thorne Vitamin D3 received a product quality score of 100/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 1 active ingredients with 30 servings per container. Of the 2 inactive ingredients, 1 are rated safe and 0 are flagged for review. The manufacturer, Thorne, holds a brand trust score of 98/100 with 10 verified certifications including Nsf Certified For Sport, Nsf Gmp, Fda Gmp Inspections, NSF Certified for Sport.

What are the ingredients in Thorne Vitamin D3?

Thorne Vitamin D3 contains 1 active ingredients: Vitamin D (100 mcg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Thorne Vitamin D3 safe to take?

Thorne Vitamin D3 has been analyzed for ingredient safety across all its components. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Thorne a trustworthy supplement brand?

Thorne receives a brand trust score of 98/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1984 and headquartered in New York, NY, United States, the company offers 204 products in their lineup. They hold 10 verified certifications including Nsf Certified For Sport, Nsf Gmp, Fda Gmp Inspections, NSF Certified for Sport. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Thorne has 2 historical regulatory incidents on record, which are factored into the trust score.

How much vitamin d3 should i take daily?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

What does vitamin d do?

This is an important question for supplement consumers. The dietary supplement industry is largely self-regulated, which means product quality, ingredient transparency, and safety practices vary significantly between brands and products. The most reliable way to evaluate any supplement is to check for third-party testing certifications, review the full ingredient list and dosages, and research the brand's regulatory track record. GoodSupp's database of over 150,000 analyzed products provides independent quality scores, ingredient safety ratings, and brand trust reports to help you make evidence-based decisions.

How much vitamin d3 per day for a woman?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

Scan Any Supplement Instantly

Download GoodSupp to scan barcodes, check ingredient safety, and find the best supplements for your needs.

Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records — read our methodology. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.