21st Century Vitamin C, 1,000 mg, 60 Tablets supplement bottle
21st Century

Vitamin C, 1,000 mg, 60 Tablets

What We Researched
2 active ingredients analyzed · 10 inactive ingredients decoded · 2 brand certifications checked · 2 retailers compared · Last updated: Mar 2026
58
Product Score Poor
76
Brand Score Fair

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Vitamin C (as Ascorbic Acid) 1,000 mg 1,111%
Calcium (as Calcium Carbonate) 52 mg 4%
Bioavailability Fair

Absorption Rating

  • Vitamin C (as Ascorbic Acid) Fair
  • Calcium (as Calcium Carbonate) Fair
Other Ingredients Fair

Fillers & Additives

  • Cellulose
  • Stearic Acid
  • Hydroxypropyl Methylcellulose
  • Croscarmellose Sodium
  • Magnesium Silicate
  • Magnesium Stearate
  • PEG Medium
  • Polyvinyl Alcohol
  • Silicone Dioxide
  • Titanium Dioxide High
Efficacy Fair

Dosage Analysis

  • Vitamin C (as Ascorbic Acid) 1,000 mg Effective
  • Calcium (as Calcium Carbonate) 52 mg Under-dosed

Supplement Facts

Ingredient Amount % Daily Value
Vitamin C (as Ascorbic Acid) 1,000 mg 1,111%
Calcium (as Calcium Carbonate) 52 mg 4%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Cellulose Safe

Provides bulk and structure in tablets and capsules.

Stearic Acid Safe

Helps ingredients flow smoothly through manufacturing equipment.

Hydroxypropyl Methylcellulose Safe

It is used as a coating for tablets and capsules.

Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Magnesium Silicate Generally_safe

It is used to improve powder flow and prevent clumping.

Magnesium Stearate Safe

Prevents ingredients from sticking to manufacturing equipment during tableting.

PEG Caution

It is used as a binder, coating, or emulsifier.

Polyvinyl Alcohol Generally_safe

It is used as a coating for tablets or capsules.

Silicone Dioxide Generally_safe

It is used as a flow agent to prevent clumping and improve powder flow.

Titanium Dioxide Caution

Used as a whitening agent in tablet coatings and capsules.

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$6$5$4$3$2 Mar 12 $4.49
iHerb

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 Vitamin C, 1 a good supplement?

21st Century Vitamin C, 1,000 mg, 60 Tablets received a product quality score of 58/100 in GoodSupp's independent analysis, indicating several areas of concern that consumers should review. The product contains 2 active ingredients Of the 10 inactive ingredients, 5 are rated safe and 2 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 Vitamin C, 1?

21st Century Vitamin C, 1 contains 2 active ingredients: Vitamin C (as Ascorbic Acid) (1,000 mg), Calcium (as Calcium Carbonate) (52 mg). Notable high-dose ingredients include Vitamin C at 1,111% DV. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is 21st Century Vitamin C, 1 safe to take?

21st Century Vitamin C, 1,000 mg, 60 Tablets has been analyzed for ingredient safety across all its components. Of 10 inactive ingredients, 5 are rated safe. 2 ingredients are flagged for review: PEG, Titanium Dioxide. 'Caution' doesn't mean dangerous — it indicates the ingredient has some considerations worth being aware of, such as potential sensitivities or ongoing research. 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.

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 250,000 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.

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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.