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Ester-C 500 mg

4.9
★ ★ ★ ★ ★
(5971 ratings)
Vitamin C 1000 mg
Product Image
Score87
A strong buffered vitamin C formula with clear calcium disclosure and good core quality. Its benefits remain concentrated in one main nutrient pathway.
How scoring works
Capsule
Quantity:120 Capsule(s) • (60 servings)
Goals:
General Health
Immunity
Skin Health
Vision Support
Anti-Inflammatory Support

Score 87

A strong buffered vitamin C formula with clear calcium disclosure and good core quality. Its benefits remain concentrated in one main nutrient pathway.
How scoring works
$13.29($0.22 per serving)
iHerb
$ 13.29
Vitacost
$ 14.63
Pure Formulas
$ 13.29
Daily Vita
$ 13.29
Vitacost
$ 14.63
Report prices

Analysis

Ester-C calcium ascorbate supplies substantial vitamin C in a buffered form that may be gentler than ordinary ascorbic acid. The calcium yield is separately disclosed, making the active contribution straightforward.

The serving provides strong depth for antioxidant defenses, collagen synthesis, and normal immune function. It remains a concentrated vitamin C formula rather than a broad nutritional blend.

Vision and skin goals receive only foundational antioxidant support because carotenoids, barrier lipids, and structural collagen are absent. It best fits users seeking high-potency buffered capsules and clear active dosing.

Who is it for
  • Adults seeking high-potency buffered vitamin C
  • People sensitive to plain ascorbic acid
  • Users who prefer calcium ascorbate capsules
Best for
  • Stomach-friendly antioxidant support
  • Collagen-cofactor nutrition
  • Foundational immune support

Pros

  • Buffered calcium ascorbate form
  • Substantial disclosed vitamin C amount
  • Clear calcium contribution

Cons

  • Limited nutrient breadth
  • No targeted eye or skin-barrier ingredients
  • Serving requires multiple capsules

Warnings

  • The large vitamin C serving may still cause digestive upset in sensitive users
  • Include the calcium contribution when tracking total supplemental calcium
  • People with kidney-stone risk or iron-overload conditions should seek guidance before sustained high-dose use

Nutrient quality

90 Highest impact

The simple active profile contains no low-value padding. The amount is high for routine use but remains below the adult tolerable upper limit.

Ingredient transparency

91 Highest impact

Vitamin C and elemental calcium amounts are stated clearly. The supplied data omit a complete inactive-ingredient list.

Customer satisfaction

74 High impact

Feedback volume is substantial enough to make the aggregate rating more stable. No complaint text is supplied, so repetitive negative themes cannot be assessed.

Value for money

87 Highest impact

No unnecessary active extras inflate the formula. A meaningful serving carries a moderate relative cost.

Report analysis

Goals

General Health
General Health
Impact
Highest effect
A- Goal FitA+ Strength of SupportC CoverageA+ Formula Quality
Vitamin C · 1000 mg

Buffered calcium ascorbate supplies a substantial vitamin C amount with good digestive tolerability. The separate calcium contribution is disclosed clearly and does not obscure the main active.

The formula provides strong depth for antioxidant, collagen, and immune-related support but remains narrow. It does not cover the full range of foundational wellness needs.

Study evidence
Vitamin C Supportive 56 studies
Immunity
Immunity
Impact
Highest effect
A- Goal FitA+ Strength of SupportC CoverageA+ Formula Quality
Vitamin C · 1000 mg

Buffered calcium ascorbate supplies a substantial vitamin C amount with good digestive tolerability. The separate calcium contribution is disclosed clearly and does not obscure the main active.

The formula provides strong depth for antioxidant, collagen, and immune-related support but remains narrow. It does not cover the full range of foundational wellness needs.

Study evidence
Vitamin C Supportive 53 studies
Skin Health
Skin Health
Impact
Highest effect
B Goal FitA+ Strength of SupportC CoverageA- Formula Quality
Vitamin C · 1000 mg

A full vitamin C serving supports collagen synthesis and antioxidant defense. The buffered calcium ascorbate form may be easier on the stomach than plain ascorbic acid.

The formula is simple and fully discloses its active amount. It offers strong vitamin C depth but no direct collagen, ceramide, or hydration ingredient.

Study evidence
Vitamin C Supportive 53 studies
Vision Support
Vision Support
Impact
High effect
B- Goal FitA Strength of SupportD+ CoverageB+ Formula Quality
Vitamin C · 1000 mg

Vitamin C provides antioxidant support for the lens and retina and is used alongside other nutrients in established eye formulas. The well-disclosed calcium ascorbate serving is substantial, but it remains a single-antioxidant approach.

Evidence for vision protection comes mainly from combinations that also include vitamin E, zinc, copper, lutein, or zeaxanthin. The formula does not support macular pigment, retinal membranes, eye-surface moisture, or ocular circulation.

Study evidence
Vitamin C Disputed 24 studies
Anti-Inflammatory Support
Anti-Inflammatory Support
Impact
High effect
C+ Goal FitA Strength of SupportD CoverageA- Formula Quality
Vitamin C · 1000 mg

A full serving of buffered vitamin C provides substantial antioxidant support that may help limit oxidative stress linked with inflammatory signaling. The simple active profile is well disclosed but does not add another meaningful anti-inflammatory pathway.

The formula is better suited to foundational antioxidant coverage than targeted modulation of major inflammatory enzymes. Its clearly stated vitamin C amount and focused design are strengths, while pathway breadth remains limited.

Study evidence
Vitamin C Supportive 50 studies

Ingredients

IngredientAmount per serving
Vitamin C (Ester-C Calcium Ascorbate)
 1000 mg
Calcium (Ester-C Calcium Ascorbate)
 110 mg
Gluten Free Adults 18–50 Dairy Free Sugar Free
Report overview
Vitamin C (Ester-C Calcium Ascorbate) · 1000 mg OverallScore90
A- Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyA+ Value

Ester-C calcium ascorbate provides a buffered vitamin C form that should be easier on the stomach than plain ascorbic acid. The full-gram serving falls within the preferred dose range, and elemental calcium is clearly disclosed. The simple active profile is easy to understand, while the missing excipient list leaves some uncertainty about label cleanliness.

View ingredientView products
Loading alternative details
89 Performance

Ester-C Plus 1000 mg Vitamin C

Solgar
<p>The ingredient profile is a stronger fit for focused vitamin C support, supplying 1000 mg of vitamin C as Ester-C with calcium and citrus bioflavonoids. The added bioflavonoids broaden the formula beyond the original’s Ester-C Calcium Ascorbate-focused ingredient profile.</p>
89 Performance

Buffered Gold C

California Gold Nutrition
<p>The ingredient profile is a stronger fit for focused vitamin C support, supplying 1000 mg of vitamin C as Sodium Ascorbate. It provides at least as much vitamin C as the original while retaining a clearly disclosed active form.</p>
88 Performance

C

Swanson
<p>The ingredient profile is a stronger fit for focused vitamin C support, supplying 1000 mg of vitamin C as Calcium Ascorbate with calcium and citrus bioflavonoids. The added bioflavonoids broaden the formula beyond the original’s Ester-C Calcium Ascorbate-focused ingredient profile.</p>
89 Budget

Pure Buffered Calcium Ascorbate

NOW
<p>A lower cost per serving makes this a practical budget alternative, while it supplies 890 mg of vitamin C as Calcium Ascorbate with calcium. The 890 mg amount is lower than the original's 1000 mg serving, so the trade-off is less vitamin C per serving.</p>
88 Budget

Sodium Ascorbate

NutriBiotic Immunity
<p>A lower cost per serving makes this a practical budget alternative, while it supplies 1100 mg of vitamin C as Sodium Ascorbate. The vitamin C amount matches or exceeds the original's 1000 mg serving.</p>
87 Budget

100% Pure Vitamin C Powder

Swanson Premium Brand
<p>A lower cost per serving makes this a practical budget alternative, while it supplies 1000 mg of vitamin C as Ascorbic Acid. The vitamin C amount matches or exceeds the original's 1000 mg serving.</p>
93 Value

Pure Buffered Magnesium Ascorbate

NOW
<p>Strong serving value is paired with 820 mg of vitamin C as Magnesium Ascorbate with magnesium. It uses a lower vitamin C amount than the original and keeps the active formula clearly disclosed, balancing cost-effectiveness with a useful ingredient profile.</p>
93 Value

Sodium Ascorbate Capsules

NutriBiotic Immunity
<p>Strong serving value is paired with 850 mg of vitamin C as Sodium Ascorbate. It uses a lower vitamin C amount than the original and keeps the active formula clearly disclosed, balancing cost-effectiveness with a useful ingredient profile.</p>
92 Value

Ester-C 500 mg With Citrus Bioflavoinds

American Health
<p>Strong serving value is paired with 1000 mg of vitamin C as Ester-C Calcium Ascorbate with calcium and citrus bioflavonoids. It matches or exceeds the original’s vitamin C amount and adds disclosed bioflavonoids, balancing cost-effectiveness with a useful ingredient profile.</p>
Report alternatives

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. 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
  3. Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis.
    Bjelakovic G; Nikolova D; Gluud LL; Simonetti RG; Gluud C · JAMA · 2007
    Meta-analysis232,606 participants68 studies pooledGeneral Health forVitamin C
  4. 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
  5. Effect of Vitamin C Supplements on Respiratory Tract Infections: A Systematic Review and Meta-Analysis.
    Keya TA; Leela A; Fernandez K; Habib N; Rashid M · Current reviews in clinical and experimental pharmacology · 2022
    Meta-analysis10 studies pooledImmunity forVitamin C
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  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