Kirkland Signature D3 50 mcg (2000 IU) supplement bottle
Kirkland Signature

D3 50 mcg (2000 IU) Review

What We Researched
1 active ingredient analyzed · 5 inactive ingredients decoded · 4 brand certifications checked · Last updated: Aug 2026
100
Product Score Excellent
80
Brand Score Good

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 D3 50 mcg 250%
Bioavailability Excellent

Absorption Rating

  • Vitamin D3 Good
Other Ingredients Excellent

Fillers & Additives

  • Soybean Oil
  • Gelatin
  • Glycerin
  • Water
  • Vitamin D3
Efficacy Excellent

Dosage Analysis

  • Vitamin D3 50 mcg Effective

Supplement Facts

Ingredient Amount % Daily Value
Vitamin D3 50 mcg 250%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Soybean Oil Safe

Dissolves fat-soluble ingredients. Contains soy allergen.

Gelatin Safe

Forms the capsule shell that holds the supplement contents.

Glycerin Safe

Retains moisture and helps dissolve ingredients in softgels and liquids.

Water Safe

Dissolves and carries water-soluble ingredients.

Vitamin D3 Safe

It is added to supplements to provide vitamin D, which is essential for bone health and immune function.

Brand Trust Report
Kirkland Signature

Founded 1995 · Issaquah, Washington, United States · 56 products · costco.com/kirkland-signature.html

Certifications

4 certifications
Usp Verified Verified Source
Informed Choice Verified
USDA Organic Verified
Gluten-Free Certified Verified

Transparency

5 claims
Third Party Testing Claim — Verified Source
Testing Lab Disclosure — Claimed
In House Testing — Claimed
Contains Proprietary Blend — True

Violation History

3 incidents
Lawsuit Falsely advertising rotisserie chicken as containing 'no preservatives'2026Source
Recall Kirkland Signature B100 Complex Timed Release2025-03-31Source
Recall Kirkland Signature Severe Cold and Flu Plus Congestion2024-11-30Source
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Frequently Asked Questions
Is Kirkland Signature D3 50 mcg (2000 IU) a good supplement?

Kirkland Signature D3 50 mcg (2000 IU) 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 600 servings per container. All 5 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, Kirkland Signature, holds a brand trust score of 80/100 with 4 verified certifications including Usp Verified, Informed Choice, USDA Organic, Gluten-Free Certified.

What are the ingredients in Kirkland Signature D3 50 mcg (2000 IU)?

Kirkland Signature D3 50 mcg (2000 IU) contains 1 active ingredients: Vitamin D3 (50 mcg). Notable high-dose ingredients include Vitamin D3 at 250% DV. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Kirkland Signature D3 50 mcg (2000 IU) safe to take?

Kirkland Signature D3 50 mcg (2000 IU) has been analyzed for ingredient safety across all its components. All 5 inactive ingredients — including capsule materials, fillers, and binders — are rated safe based on regulatory data and published safety research. This is a clean formulation with no controversial additives. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Kirkland Signature a trustworthy supplement brand?

Kirkland Signature receives a brand trust score of 80/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1995 and headquartered in Issaquah, Washington, United States, the company offers 56 products in their lineup. They hold 4 verified certifications including Usp Verified, Informed Choice, USDA Organic, Gluten-Free Certified. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Kirkland Signature has 3 historical regulatory incidents on record, which are factored into the trust score.

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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.