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Buffered C-500

4.7
★ ★ ★ ★ ★
(432 ratings)
Vitamin C 500 mg
Product Image
Score81
A practical, partly buffered 500 mg vitamin C capsule with a large supply. Form-level labeling could be clearer.
How scoring works
Capsule
Quantity:250 Capsule(s) • (250 servings)
Goals:
Immunity
General Health
Skin Health

Score 81

A practical, partly buffered 500 mg vitamin C capsule with a large supply. Form-level labeling could be clearer.
How scoring works
$21.49($0.08 per serving)
iHerb
$ 21.49
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Analysis

A 500 mg vitamin C serving sits in a practical range for daily antioxidant and collagen support. Including calcium ascorbate may reduce acidity compared with a formula based only on ascorbic acid.

The capsule format is easy to use and the large count supports consistent use. Its two listed vitamin C forms create some ambiguity because their individual contribution to total active vitamin C is not explained clearly.

The formula remains focused and does not add wider immune or skin nutrients. It best fits someone who wants basic vitamin C with partial buffering rather than an advanced multi-ingredient product.

Who is it for
  • Adults seeking a moderate vitamin C amount
  • Users who prefer capsules
  • People wanting some buffering without a complex blend
Best for
  • Routine vitamin C support
  • Convenient long-term use
  • Antioxidant and collagen support

Pros

  • Well-targeted 500 mg serving
  • Includes a buffered ascorbate form
  • Large capsule count

Cons

  • Individual form contributions are unclear
  • Still contains plain ascorbic acid
  • No complementary nutrients

Nutrient quality

91 Highest impact

Calcium ascorbate adds buffering to established ascorbic acid. The stated vitamin C serving is meaningful for routine supplemental use.

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Ingredient transparency

74 High impact

The total vitamin C amount is apparent, but the contribution from each form is not clearly separated. A complete inactive ingredient list was not supplied.

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Customer satisfaction

66 High impact

The available aggregate rating is strong for this category. No firsthand outcome details were supplied, so alignment with the intended use is uncertain.

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Value for money

92 Highest impact

Partial buffering and a meaningful amount provide good quality for the serving cost. The product is competitive among basic partially buffered vitamin C capsules.

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Goals

Immunity
Immunity
Impact
Highest effect
A- Goal FitA Strength of SupportC- CoverageA+ Formula Quality
Vitamin C · 500 mg

Vitamin C directly supports antioxidant defenses and normal immune-cell activity with strong evidence. The formula is intentionally narrow and does not cover zinc, vitamin D, or barrier-focused pathways.

The amount meets the key target and calcium ascorbate adds useful buffering. Both forms are named, although their individual contributions and the calcium amount are not separated.

Study evidence
Vitamin C Supportive 53 studies
General Health
General Health
Impact
Highest effect
A Goal FitA- Strength of SupportC CoverageA Formula Quality
Vitamin C · 500 mg

Vitamin C provides established antioxidant and collagen-supporting nutrition in a practical daily amount. Calcium ascorbate adds partial buffering that may improve comfort for some users.

The split between the two vitamin C forms is not disclosed, which limits full assessment of the buffered contribution. The focused capsule offers useful depth for one nutrient but little broader pathway coverage.

Study evidence
Vitamin C Supportive 56 studies
Skin Health
Skin Health
Impact
High effect
B Goal FitB+ Strength of SupportD+ CoverageA Formula Quality
Vitamin C · 500 mg

Vitamin C supports collagen synthesis and antioxidant defense, giving the formula a clear but narrow skin-health role. Calcium ascorbate adds partial buffering to the ordinary ascorbic acid base.

Separate contributions from each vitamin C form and the accompanying calcium amount are not disclosed. A single vitamin C product does not directly supply collagen peptides, barrier lipids, or dedicated hydration actives.

Study evidence
Vitamin C Supportive 53 studies
Anti-Inflammatory Support
Cellular Defense
Anti-Inflammatory Support
Impact
Moderate effect
D+ Goal FitB- Strength of SupportF CoverageA+ Formula Quality
Vitamin C · 500 mg

Buffered vitamin C provides a useful antioxidant amount with improved stomach tolerance. Vitamin C may support oxidative balance but does not directly cover major inflammatory enzyme pathways.

The calcium ascorbate form is practical, although the individual contributions of each vitamin C source are not shown. The lean formula offers focused antioxidant support rather than broad anti-inflammatory action.

Study evidence
Vitamin C Supportive 50 studies
Vision Support
Macular and Blue Light Defense
Vision Support
Impact
Moderate effect
F Goal FitB- Strength of SupportF CoverageB- Formula Quality
Vitamin C · 500 mg

Vitamin C supports ocular antioxidant defenses but does not directly supply macular pigment or retinal lipids. The useful amount includes calcium ascorbate for partial buffering, although the separate form contributions are not stated.

The formula covers one broad antioxidant pathway rather than comprehensive vision support. Lutein, zeaxanthin, zinc-copper balance, and DHA are absent.

Study evidence
Vitamin C Disputed 24 studies

Ingredients

IngredientAmount per serving
Vitamin C (Ascorbic Acid, Calcium Ascorbate)
 500 mg
Gluten Free Adults 18–50 Dairy Free
Report overview
Vitamin C (Ascorbic Acid, Calcium Ascorbate) · 500 mg OverallScore77
C Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyB+ Value

Calcium ascorbate adds partial buffering to a target-range vitamin C serving. The label names both forms but does not disclose their separate contributions or the calcium amount. Cost efficiency is favorable, making it practical when full mineral transparency is not essential.

View ingredientView products
Loading alternative details
89 Performance

Pure Buffered Calcium Ascorbate

NOW
A more performance-focused option combines 890 mg of vitamin C as Calcium Ascorbate with 100 mg of Calcium. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
88 Performance

Buffered Gold C

California Gold Nutrition
A more performance-focused option combines 1,000 mg of vitamin C as Sodium Ascorbate with a focused single-nutrient formula. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
85 Performance

Ester-C Plus 1000 mg Vitamin C

Solgar
A more performance-focused option combines 1,000 mg of vitamin C as Ester-C with 108 mg of Calcium and 200 mg of Citrus Bioflavonoids Complex. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
87 Budget

Pure Buffered Magnesium Ascorbate

NOW
The lower serving cost still provides 820 mg of vitamin C as Magnesium Ascorbate with 60 mg of Magnesium. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
84 Budget

Ester-C 500 mg With Citrus Bioflavoinds

American Health
The lower serving cost still provides 1,000 mg of vitamin C as Ester-C Calcium Ascorbate with 110 mg of Calcium and 400 mg of Citrus Bioflavonoids Complex. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
88 Budget

Sodium Ascorbate

NutriBiotic Immunity
The lower serving cost still provides 1,100 mg of vitamin C as Sodium Ascorbate with a focused single-nutrient formula. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
85 Value

C-500 With Rose Hips

NOW
The favorable serving cost pairs 500 mg of vitamin C as Ascorbic Acid with 40 mg of Rose Hips powder. The vitamin C amount is similar to the original, while the added ingredients and label details determine the more useful fit.
87 Value

100% Pure Vitamin C Powder

Swanson Premium Brand
The favorable serving cost pairs 1,000 mg of vitamin C as Ascorbic Acid with a focused single-nutrient formula. Compared with the original's 500 mg of vitamin C as Ascorbic Acid, the larger disclosed amount may better fit users seeking higher-potency vitamin C.
87 Value

C 500 mg

Mason Natural
The favorable serving cost pairs 500 mg of vitamin C as Ascorbic Acid with a focused single-nutrient formula. The vitamin C amount is similar to the original, while the added ingredients and label details determine the more useful fit.
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Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Vitamin C intake and multiple health outcomes: an umbrella review of systematic reviews and meta-analyses.
    Xu K; Peng R; Zou Y; Jiang X; Sun Q; Song C · International journal of food sciences and nutrition · 2022
    Meta-analysis76 studies pooledGeneral Health forVitamin C
  2. Supplemental Vitamins and Minerals for Cardiovascular Disease Prevention and Treatment: JACC Focus Seminar.
    Jenkins DJA; Spence JD; Giovannucci EL; Kim YI; Josse RG; Vieth R; Sahye-Pudaruth S; Paquette M; Patel D; Blanco Mejia S; Viguiliouk E; Nishi SK; Kavanagh M; Tsirakis T; Kendall CWC; Pichika SC; Sievenpiper JL · Journal of the American College of Cardiology · 2021
    Meta-analysisGeneral Health forVitamin C
  3. Dietary nutrient intakes and skin-aging appearance among middle-aged American women.
    Cosgrove MC; Franco OH; Granger SP; Murray PG; Mayes AE · The American journal of clinical nutrition · 2007
    Cross-sectional study4,025 participantsSkin Health forVitamin C
  4. Double-blind, half-face study comparing topical vitamin C and vehicle for rejuvenation of photodamage.
    Fitzpatrick RE; Rostan EF · Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] · 2002
    Non-randomized trial10 participantsSkin Health forVitamin C
  5. Efficacy of Vitamin C as Glucocorticoid Substitute for Reducing Pain and Inflammation After Total Hip Arthroplasty: A Randomized Controlled Trial.
    Jiang W; Xu H; Jiang X; Zhan Y; Ju Y; Xie J; Huang Z; Huang Q; Pei F · The Journal of bone and joint surgery. American volume · 2025
    Randomized trial107 participantsAnti-Inflammatory Support forVitamin C
  6. The Impact of Vitamin C on Analgesic, Anti-inflammatory, and Hemostatic Outcomes After Total Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis.
    Moftakhari Hajimirzaei S; Bagherzadeh Cham M; Dolikhani M; Tabatabaee SM; Ebrahimpour A · The archives of bone and joint surgery · 2026
    Meta-analysis1,162 participants10 studies pooledAnti-Inflammatory Support forVitamin C
  7. The impact of vitamin C supplementation on the perioperative outcomes after total hip and knee arthroplasty: a systematic review and meta-analysis.
    Liu X; Guo J; Li Y; Yang Y; Liu M; Gao Q; Yang Y; Wu X; Yue C · BMC musculoskeletal disorders · 2026
    Meta-analysis852 participants8 studies pooledAnti-Inflammatory Support forVitamin C
  8. Therapeutic Impact of Ascorbic Acid on Oral and Periodontal Tissues: A Systematic Literature Review.
    Ruzijevaite G; Acaite E; Jagelaviciene E · Medicina (Kaunas, Lithuania) · 2025
    Systematic review811 participants17 studies pooledAnti-Inflammatory Support forVitamin C
  9. Oral vitamin C administration reduces early recurrence rates after electrical cardioversion of persistent atrial fibrillation and attenuates associated inflammation.
    Korantzopoulos P; Kolettis TM; Kountouris E; Dimitroula V; Karanikis P; Pappa E; Siogas K; Goudevenos JA · International journal of cardiology · 2005
    Randomized trial44 participantsAnti-Inflammatory Support forVitamin C
  10. Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies.
    Aune D; Keum N; Giovannucci E; Fadnes LT; Boffetta P; Greenwood DC; Tonstad S; Vatten LJ; Riboli E; Norat T · The American journal of clinical nutrition · 2019
    Meta-analysis69 studies pooledGeneral Health forVitamin C
  11. Scientific Opinion on the substantiation of a health claim related to vitamin C and increasing non haem iron absorption pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusGeneral Health forVitamin C
  12. Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients.
    Sotomayor CG; Eisenga MF; Gomes Neto AW; Ozyilmaz A; Gans ROB; Jong WHA; Zelle DM; Berger SP; Gaillard CAJM; Navis GJ; Bakker SJ · Nutrients · 2018
    Cohort study598 participantsGeneral Health forVitamin C
  13. Associations of Serum Biomarkers of Fruit and Vegetable Intake With the Risk of Cause-Specific Mortality and All-Cause Mortality: A National Prospective Cohort Study.
    Pu L; Zhang R; Wang X; Zhao T; Sun H; Han L · Frontiers in nutrition · 2022
    Cohort study12,530 participantsGeneral Health forVitamin C
  14. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition.
    Khaw KT; Bingham S; Welch A; Luben R; Wareham N; Oakes S; Day N · Lancet (London, England) · 2001
    Cohort study19,496 participantsGeneral Health forVitamin C
  15. Vitamin C and contribution to the normal function of the immune system: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusImmunity forVitamin C
  16. Therapeutic effects of high-dose vitamin C supplementation in patients with COVID-19: a meta-analysis.
    Sun L; Zhao JH; Fan WY; Feng B; Liu WW; Chen RQ; Ban C; Dang AG; Wang M; Luo KT; Zhou GY; Yu FF; Ba Y · Nutrition reviews · 2024
    Meta-analysis2,334 participants14 studies pooledImmunity forVitamin C
  17. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis.
    Abioye AI; Bromage S; Fawzi W · BMJ global health · 2021
    Meta-analysisImmunity forVitamin C
  18. New evidence for antioxidant properties of vitamin C.
    Vojdani A; Bazargan M; Vojdani E; Wright J · Cancer detection and prevention · 2001
    Randomized trial20 participantsImmunity forVitamin C
  19. Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement Forms in Healthy Adults.
    Calder PC; Kreider RB; McKay DL · Nutrients · 2025
    Systematic review13 studies pooledImmunity forVitamin C
  20. Evaluation of the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch via a double-blind, placebo-controlled clinical study.
    Lee C; Yang H; Kim S; Kim M; Kang H; Kim N; An S; Koh J; Jung H · International journal of cosmetic science · 2017
    Randomized trial23 participantsSkin Health forVitamin C
  21. Comparative Study on the Outcome of Periorbital Wrinkles Treated with Laser-Assisted Delivery of Vitamin C or Vitamin C Plus Growth Factors: A Randomized, Double-blind, Clinical Trial.
    Machado BHB; Frame J; Zhang J; Najlah M · Aesthetic plastic surgery · 2021
    Randomized trial149 participantsSkin Health forVitamin C
  22. Randomized trial of topical ascorbic acid in DMSO versus imiquimod for the treatment of basal cell carcinoma.
    Burke B; Bailie JE · Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2022
    Randomized trial25 participantsSkin Health forVitamin C
  23. Vitamin C improves healing of foot ulcers: a randomised, double-blind, placebo-controlled trial.
    Gunton JE; Girgis CM; Lau T; Vicaretti M; Begg L; Flood V · The British journal of nutrition · 2022
    Randomized trial16 participantsSkin Health forVitamin C
  24. Role of Oral Vitamin 'C' on Astigmatic Errors in Phacoemulsification.
    Mohan S; Sah K; Khattri M; Ahmad L; Sachan SK · Current eye research · 2021
    Randomized trial400 participantsVision Support forVitamin C
  25. Ascorbic acid metabolites are involved in intraocular pressure control in the general population.
    Hysi PG; Khawaja AP; Menni C; Tamraz B; Wareham N; Khaw KT; Foster PJ; Benet LZ; Spector TD; Hammond CJ · Redox biology · 2019
    Observational studyVision Support forVitamin C
  26. Nutritional modulation of cataract.
    Weikel KA; Garber C; Baburins A; Taylor A · Nutrition reviews · 2014
    Narrative reviewVision Support forVitamin C
  27. Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan.
    Aoki A; Inoue M; Nguyen E; Obata R; Kadonosono K; Shinkai S; Hashimoto H; Sasaki S; Yanagi Y · Scientific reports · 2017
    Case-control study530 participantsVision Support forVitamin C
  28. Adherence to a Mediterranean diet, lifestyle and age-related macular degeneration: the Coimbra Eye Study - report 3.
    Raimundo M; Mira F; Cachulo MDL; Barreto P; Ribeiro L; Farinha C; Laíns I; Nunes S; Alves D; Figueira J; Merle BM; Delcourt C; Santos L; Silva R · Acta ophthalmologica · 2019
    Case-control study883 participantsVision Support forVitamin C