21st Century D3 25 mcg (1000 IU) supplement bottle
21st Century

D3 25 mcg (1000 IU)

What We Researched
2 active ingredients analyzed · 5 inactive ingredients decoded · 2 brand certifications checked · 2 retailers compared · Last updated: Mar 2026
81
Product Score Good
76
Brand Score Fair

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Vitamin D3 (as Cholecalciferol) 25 mcg 130%
Calcium (as Calcium Carbonate) 90 mg 6%
Bioavailability Very Good

Absorption Rating

  • Vitamin D3 (as Cholecalciferol) Good
  • Calcium (as Calcium Carbonate) Fair
Other Ingredients Excellent

Fillers & Additives

  • Cellulose
  • Croscarmellose Sodium
  • Maltodextrin
  • Stearic Acid
  • Contains Less Than 2% of
Efficacy Fair

Dosage Analysis

  • Vitamin D3 (as Cholecalciferol) 25 mcg Effective
  • Calcium (as Calcium Carbonate) 90 mg Under-dosed

Supplement Facts

Ingredient Amount % Daily Value
Vitamin D3 (as Cholecalciferol) 25 mcg 130%
Calcium (as Calcium Carbonate) 90 mg 6%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Cellulose Safe

Provides bulk and structure in tablets and capsules.

Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Maltodextrin Generally_safe

Helps carry and stabilize active ingredients. Provides bulk.

Stearic Acid Safe

Helps ingredients flow smoothly through manufacturing equipment.

Contains Less Than 2% of Unknown

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$10$9$8$7$6 $8.02
Target

Prices shown at time of last check. Click a retailer to see current price. GoodSupp is not affiliated with any retailer.

Brand Trust Report
21st Century

Founded 1991 · Tempe, Arizona, United States · 231 products · 21stcenturyvitamins.com/

Certifications

2 certifications
Consumerlab Verified
Nsf Gmp Verified Source

Transparency

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

Violation History

4 incidents
Prop 65 Lead2021-06-22Source
Recall Vitamin D3 5000 IU Tablets2021-05-19Source
Lawsuit False advertising of Glucosamine/Chondroitin supplements.2012Source
Prop 65 Lead2008-12-23Source
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Frequently Asked Questions
Is 21st Century D3 25 mcg (1000 IU) a good supplement?

21st Century D3 25 mcg (1000 IU) received a product quality score of 81/100 in GoodSupp's independent analysis, indicating strong overall quality. The product contains 2 active ingredients Of the 5 inactive ingredients, 3 are rated safe and 0 are flagged for review. The manufacturer, 21st Century, holds a brand trust score of 76/100 with 2 verified certifications including Consumerlab, Nsf Gmp.

What are the ingredients in 21st Century D3 25 mcg (1000 IU)?

21st Century D3 25 mcg (1000 IU) contains 2 active ingredients: Vitamin D3 (as Cholecalciferol) (25 mcg), Calcium (as Calcium Carbonate) (90 mg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is 21st Century D3 25 mcg (1000 IU) safe to take?

21st Century D3 25 mcg (1000 IU) 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 21st Century a trustworthy supplement brand?

21st Century receives a brand trust score of 76/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1991 and headquartered in Tempe, Arizona, United States, the company offers 231 products in their lineup. They hold 2 verified certifications including Consumerlab, Nsf Gmp. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: 21st Century has 4 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. 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.