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Buffered Vitamin C Powder

Life Extension
4.7
★ ★ ★ ★ ★
(1108 ratings)
Potassium 365 mg
Vitamin C 4000 mg
Product Image
Score81
Clear, flexible, and economical buffered vitamin C powder, but the full 4,000 mg serving is unnecessarily large for most adults.
How scoring works
Quantity:454 Gram(s) • (84 servings)
Goals:
Immunity
General Health

Score 81

Clear, flexible, and economical buffered vitamin C powder, but the full 4,000 mg serving is unnecessarily large for most adults.
How scoring works
$21.00($0.25 per serving)
Pure Formulas
$ 21.00
Vitacost
$ 22.83
Vitacost
$ 22.83
iHerb
$ 21.00
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Analysis

A very large ascorbic acid serving is partially buffered by calcium, magnesium, and potassium carbonates. The powder offers flexible measuring and clearly states every active amount, which makes it easy to adjust below the full serving.

Potassium contributes a useful 365 mg, but the other supporting minerals are modest and do not turn the powder into a comprehensive mineral supplement. The formula remains focused, with no proprietary blends or distracting botanical additions.

Four grams of vitamin C exceeds the adult daily upper limit and is poorly matched to routine nutritional needs. People who choose it should value dose flexibility and consider using less than a full serving rather than treating the label serving as a daily target.

Who is it for
  • Adults who want a powder that can be measured into smaller servings
  • People who find plain ascorbic acid too acidic
  • Users seeking vitamin C with a useful amount of potassium
Best for
  • Flexible vitamin C dosing
  • Partially buffered powder supplementation
  • Low-cost long-term supply when used in smaller amounts

Pros

  • Simple formula with all active amounts disclosed
  • Mineral carbonates partially buffer the ascorbic acid
  • Powder format allows serving-size adjustment
  • Provides 365 mg potassium per full serving

Cons

  • The full serving supplies an excessive 4,000 mg vitamin C
  • Supporting zinc and magnesium amounts are modest
  • Carbonate forms are functional but not especially advanced
  • A large tub is less convenient than single-dose formats

Warnings

  • The 4,000 mg vitamin C serving exceeds the adult upper intake level and can cause diarrhea, cramping, or nausea.
  • People prone to calcium-oxalate kidney stones should avoid routine use of the full vitamin C serving unless a qualified professional advises it.
  • The 365 mg potassium amount should be counted by people with impaired kidney function or those using potassium-retaining medicines such as ACE inhibitors, ARBs, or potassium-sparing diuretics.

Nutrient quality

76 High impact

Alkaline mineral carbonates partly buffer the ascorbic acid powder. The very large vitamin C serving is unnecessarily aggressive for routine general use.

Ingredient transparency

85 Highest impact

Listed active amounts are clear and no proprietary blend hides a key dose. Complete directions and inactive-ingredient details remain incomplete.

Customer satisfaction

72 High impact

The aggregate rating and its volume provide a favorable top-level signal. Missing experience details prevent assessment of repeated complaints or purpose-specific satisfaction.

Value for money

91 Highest impact

Low ingredient cost and a simple powder format provide strong value. The focused composition supports a strong formula-to-cost balance.

Report analysis

Goals

Immunity
Immunity
Impact
Highest effect
A+ Goal FitC Strength of SupportC+ CoverageA Formula Quality
Magnesium · 55 mgVitamin C · 4000 mgZinc · 2 mg

Vitamin C directly supports immune-cell function, barrier integrity, and antioxidant protection. The 4,000 mg amount is far above the efficiently absorbed range, while alkaline minerals partially buffer its acidity.

The powder is focused and clearly labels each mineral, but the small zinc amount adds little immune depth. The oversized vitamin C serving may cause loose stools or stomach upset, especially when taken at once.

Study evidence
Vitamin C Supportive 53 studies
Zinc Supportive 73 studies
General Health
General Health
Impact
High effect
A- Goal FitC Strength of SupportC CoverageA- Formula Quality
Magnesium · 55 mgZinc · 2 mgVitamin C · 4000 mg

Vitamin C provides clear antioxidant, immune, and collagen support, while mineral carbonates partially buffer its acidity. The very large serving exceeds efficient routine use and may cause loose stools or stomach upset.

Small amounts of magnesium, zinc, calcium, and potassium add limited breadth but do not make the formula comprehensive. Full dose disclosure and a simple ingredient list are strengths despite the imbalanced vitamin C emphasis.

Study evidence
Magnesium Supportive 114 studies
Vitamin C Supportive 56 studies
Zinc Supportive 60 studies
Skin Health
Skin Health
Impact
Moderate effect
B- Goal FitC- Strength of SupportD CoverageB Formula Quality
Zinc · 2 mgVitamin C · 4000 mg

Vitamin C directly supports collagen synthesis and antioxidant protection, making it relevant to normal skin function. The serving is far larger than needed for efficient support and does not add collagen, hydration, or barrier actives.

Buffering minerals may improve comfort compared with plain acid, and every amount is disclosed. The 4,000 mg vitamin C serving may cause loose stools or stomach upset in sensitive users.

Study evidence
Vitamin C Supportive 53 studies
Cardiovascular Support
Cardiovascular Support
Impact
Moderate effect
C- Goal FitC Strength of SupportC- CoverageB Formula Quality
Potassium · 365 mgMagnesium · 55 mgVitamin C · 4000 mg

Potassium supports vascular tone, while vitamin C provides antioxidant support, but the formula is not specifically heart focused. Human evidence supports adequate potassium for blood pressure, while very high vitamin C has limited added cardiovascular benefit.

The potassium amount is useful but modest, while the 4,000 mg vitamin C amount greatly exceeds efficient absorption needs. All mineral sources are disclosed, but the formula relies on plain ascorbic acid and basic carbonate forms. The 4,000 mg vitamin C amount can cause diarrhea and may raise kidney-stone risk in susceptible people.

Study evidence
Potassium Supportive 117 studies
Vitamin C Supportive 101 studies
Anti-Inflammatory Support
Anti-Inflammatory Support
Impact
Moderate effect
C+ Goal FitD Strength of SupportD+ CoverageB+ Formula Quality
Vitamin C · 4000 mg

Vitamin C supports antioxidant recycling and may limit oxidative stress that accompanies inflammation. The very large serving exceeds the efficient supplemental range and does not add proportionally greater benefit.

Alkaline minerals partly buffer the ascorbic acid and all amounts are clearly disclosed. The 4,000 mg vitamin C amount may cause loose stools or stomach upset in sensitive users.

Study evidence
Vitamin C Supportive 50 studies
Heart Health
Heart Health
Impact
Moderate effect
D Goal FitC- Strength of SupportD+ CoverageC+ Formula Quality
Magnesium · 55 mg

Potassium and magnesium offer some vascular support, but the formula is dominated by vitamin C. It provides 4,000 mg of vitamin C, 365 mg of potassium, and small mineral amounts for the stated purpose.

The potassium amount is modest and the vitamin C amount is excessive for routine heart support. The 4,000 mg vitamin C amount can cause diarrhea and may raise kidney-stone risk in susceptible users.

Study evidence
Magnesium Supportive 158 studies
Potassium Supportive 182 studies
Vision Support
Vision Support
Impact
Moderate effect
C+ Goal FitD- Strength of SupportF CoverageC Formula Quality
Zinc · 2 mgVitamin C · 4000 mg

Vitamin C supports antioxidant defense in the lens and retina, but the 4000 mg serving is far beyond what is needed for nutritional adequacy. Vision evidence for vitamin C comes mainly from balanced antioxidant combinations rather than very high-dose vitamin C alone.

The formula does not provide lutein, zeaxanthin, zinc at an AREDS-style amount, vitamin E, or omega-3 fats. A dose this large can cause diarrhea and abdominal cramping, and may increase kidney-stone risk in susceptible users.

Study evidence
Vitamin C Disputed 24 studies
Zinc Supportive 39 studies

Ingredients

IngredientAmount per serving
Vitamin C (Ascorbic Acid)
 4000 mg
Calcium (Calcium Carbonate)
 145 mg
Magnesium (Magnesium Carbonate)
 55 mg
Zinc (Zinc Gluconate)
 2 mg
Potassium (Potassium Carbonate)
 365 mg
Gluten Free Adults 18–50 Vegetarian
Report overview
Potassium (Potassium Carbonate) · 365 mg OverallScore83
B+ Active Ingredient Quality & BioavailabilityB Dose, Safety & Label TransparencyA+ Value

Potassium carbonate supplies an effective 365 mg amount at a low serving cost. Its alkalizing character is useful, though it is less directly supported by the preferred-form list than citrate or bicarbonate. The label states the potassium amount but does not separate compound weight from elemental yield.

View ingredientView products
Vitamin C (Ascorbic Acid) · 4000 mg OverallScore66
F Active Ingredient Quality & BioavailabilityB Dose, Safety & Label TransparencyA+ Value

The powder combines plain ascorbic acid with alkaline minerals that partially buffer its acidity. Its very large Vitamin C serving is well above the efficient target and may cause loose stools or stomach upset in sensitive users. Clear mineral quantities, a simple ingredient profile, and low cost per gram are meaningful strengths.

View ingredientView products
Loading alternative details
89 Performance

Pure Buffered Calcium Ascorbate

NOW
<p>Buffered calcium ascorbate offers a gentler, clearly dosed vitamin C form than the original very large vitamin C serving. The focused powder omits potassium and does not provide complete use or inactive-ingredient details.</p>
87 Performance

Potassium Bicarbonate 1.3 g

Nutricost
<p>Potassium bicarbonate provides a meaningful, well-absorbed amount in a simple alkalizing powder instead of the original very large vitamin C serving. It does not replace the original vitamin C, and kidney impairment or potassium-retaining medicines make unsupervised use unsafe.</p>
82 Performance

Liposomal Vitamin C 1000 mg

SunLipid
<p>Buffered vitamin C, phospholipids, and MCT create a more purposeful delivery system than the original very large vitamin C serving. The sodium contribution may matter on a strict limit, and the formula does not replace the original potassium.</p>
85 Budget

C-500 With Rose Hips

NOW
<p>The serving cost is lower than the original. A focused vitamin C serving avoids the original very large vitamin C serving, although plain ascorbic acid may bother sensitive stomachs.</p>
85 Budget

Potassium Chloride 365 mg

Nutricost
<p>The serving cost is lower than the original. Potassium chloride supplies a meaningful electrolyte amount without the original very large vitamin C serving, but it omits vitamin C and lacks the buffering role of citrate or bicarbonate.</p>
85 Budget

Gold C Vitamin C 1000 mg

California Gold Nutrition
<p>The serving cost is lower than the original. A substantial plain vitamin C serving avoids the original very large vitamin C serving, though the unbuffered form and missing carrier details reduce confidence for sensitive users.</p>
89 Value

C-500 Calcium Ascorbate-C

NOW
<p>Buffered calcium ascorbate gives a practical vitamin C amount with clear mineral disclosure and strong serving value compared with the original very large vitamin C serving. The smaller vitamin C amount and lack of potassium make it a focused rather than complete substitute.</p>
82 Value

Meta-C 1000 mg Tablets

NutriBiotic Immunity
<p>A clearly disclosed vitamin C complex with named metabolites offers strong value and a potentially gentler format than the original very large vitamin C serving. Spirulina adds limited clarity, and the formula does not cover potassium.</p>
81 Value

Potassium (Citrate)

Pure Encapsulations
<p>Potassium citrate supplies a well-absorbed, alkalizing form at a modest serving cost instead of relying on the original very large vitamin C serving. The amount is moderate and vitamin C is absent, while kidney disease or potassium-retaining medicines can make supplementation unsafe.</p>
Report alternatives

Sources

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

  1. 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
  2. Vitamin C supplementation in kidney failure: effect on uraemic symptoms.
    Singer RF · Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association · 2011
    Randomized trial99 participantsGeneral Health forVitamin C
  3. Serum vitamin C and spinal pain: a nationwide study.
    Dionne CE; Laurin D; Desrosiers T; Abdous B; Le Sage N; Frenette J; Mondor M; Pelletier S · Pain · 2017
    Cross-sectional study4,742 participantsGeneral Health forVitamin C
  4. 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
  5. Vitamin C for the management of COVID-19: a systematic review and meta-analysis of randomized controlled trials.
    Abid H; Mushtaq I; Munir ABI; Shakil J; Vinjamuri S; Tadasare N; Kiran F; Muhammad Wali Mirza A; Fatima Khidri F; Shahid A; Ayyan M; Ehsan M; Cheema HA; Alsubari AMA; Sahra S; Siddiqi NI · Annals of medicine and surgery (2012) · 2026
    Meta-analysis9 studies pooledGeneral Health forVitamin C
  6. Evaluating the effects of chlorhexidine and vitamin c mouthwash on oral health in non-surgical periodontal therapy: a randomized controlled clinical trial.
    Ozmeric N; Enver A; Isler SC; Gökmenoğlu C; Topaloğlu M; Selamet H; Altun G; Aykol Sayar S · Scientific reports · 2025
    Randomized trial60 participantsGeneral Health forVitamin C
  7. 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
  8. Ascorbate for Organ Dysfunction in Critically Ill Patients With Sepsis: The Phase 2b ASTER Trial.
    Files DC; Matthay MA; Ware LB; Brower RG; Aggarwal NR; Brown SM; Chang SY; Douglas IS; Duggal A; Gibbs KW; Fields S; Foulkes AS; Ginde A; Goodwin A; Harris ES; Hendey GW; Hibbert K; Hite RD; Hough CL; Huang W; Khan A; Lai P; Liu KD; Miller C; Moskowitz A; Riker R; Robinson BRH; Self WH; Tidswell MA; Yealy DM; Thompson BT; Fowler AA · CHEST critical care · 2026
    Randomized trial79 participantsGeneral Health forVitamin C
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. Sex-specific associations between sodium and potassium intake and overall and cause-specific mortality: a large prospective U.S. cohort study, systematic review, and updated meta-analysis of cohort studies.
    Gan L; Zhao B; Inoue-Choi M; Liao LM; Graubard BI; Weinstein SJ; Albanes D; Huang J · BMC medicine · 2024
    Meta-analysis416,104 participantsCardiovascular Support forPotassium
  17. Potassium intake, stroke, and cardiovascular disease a meta-analysis of prospective studies.
    D'Elia L; Barba G; Cappuccio FP; Strazzullo P · Journal of the American College of Cardiology · 2011
    Meta-analysis247,510 participants11 studies pooledCardiovascular Support Heart Health forPotassium
  18. Blood pressure response to changes in sodium and potassium intake: a metaregression analysis of randomised trials.
    Geleijnse JM; Kok FJ; Grobbee DE · Journal of human hypertension · 2003
    Meta-analysis27 studies pooledCardiovascular Support forPotassium
  19. Twenty-Four-Hour Urinary Sodium and Potassium Excretion and Their Associations With Blood Pressure Among Adults in China: Baseline Survey of Action on Salt China.
    Li Y; Zhang P; Wu J; Ma J; Xu J; Zhang X; Luo R; Liu M; Sun Y; Li X; Tan M; He FJ; MacGregor GA; Li X · Hypertension (Dallas, Tex. : 1979) · 2021
    Cross-sectional study5,353 participantsCardiovascular Support forPotassium
  20. Dietary Sodium and Potassium Intake and Risk of Non-Fatal Cardiovascular Diseases: The Million Veteran Program.
    Wang DD; Li Y; Nguyen XT; Song RJ; Ho YL; Hu FB; Willett WC; Wilson PWF; Cho K; Gaziano JM; Djoussé L; On Behalf Of The Va Million Veteran Program · Nutrients · 2022
    Cohort study180,156 participantsCardiovascular Support forPotassium
  21. Vitamin C may reduce troponin and CKMB levels after PCI and CABG: a meta-analysis.
    Rozemeijer S; Hemilä H; van Baaren M; de Man AME · BMC cardiovascular disorders · 2023
    Meta-analysis872 participants7 studies pooledCardiovascular Support forVitamin C
  22. Vitamin C improves endothelium-dependent vasodilation by restoring nitric oxide activity in essential hypertension.
    Taddei S; Virdis A; Ghiadoni L; Magagna A; Salvetti A · Circulation · 1998
    Clinical trial49 participantsCardiovascular Support forVitamin C
  23. Vitamin C supplementation improves blood pressure and oxidative stress after acute exercise in patients with poorly controlled type 2 diabetes mellitus: A randomized, placebo-controlled, cross-over study.
    Boonthongkaew C; Tong-Un T; Kanpetta Y; Chaungchot N; Leelayuwat C; Leelayuwat N · The Chinese journal of physiology · 2021
    Randomized trial24 participantsCardiovascular Support forVitamin C
  24. Vascular benefits of vitamin C supplementation against fine particulate air pollution in healthy adults: A double-blind randomised crossover trial.
    Ren J; Liang J; Wang J; Yin B; Zhang F; Li X; Zhu S; Tian H; Cui Q; Song J; Liu G; Ling W; Ma Y · Ecotoxicology and environmental safety · 2022
    Randomized trial58 participantsCardiovascular Support forVitamin C
  25. Ascorbic acid reduces blood pressure and arterial stiffness in type 2 diabetes.
    Mullan BA; Young IS; Fee H; McCance DR · Hypertension (Dallas, Tex. : 1979) · 2003
    Randomized trial30 participantsCardiovascular Support forVitamin C
  26. Perioperative systemic magnesium to minimize postoperative pain: a meta-analysis of randomized controlled trials.
    De Oliveira GS; Castro-Alves LJ; Khan JH; McCarthy RJ · Anesthesiology · 2013
    Meta-analysis1,257 participants20 studies pooledGeneral Health forMagnesium
  27. Long-term outcome after intravenous magnesium sulphate in suspected acute myocardial infarction: the second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2).
    Woods KL; Fletcher S · Lancet (London, England) · 1994
    Randomized trial2,316 participantsGeneral Health forMagnesium
  28. Association of magnesium sulfate use with mortality in critically ill patients with sepsis: a retrospective propensity score-matched cohort study.
    Gu WJ; Duan XJ; Liu XZ; Cen Y; Tao LY; Lyu J; Yin HY · British journal of anaesthesia · 2023
    Cohort study10,999 participantsGeneral Health forMagnesium
  29. Hypomagnesemia and Mortality in Incident Hemodialysis Patients.
    Li L; Streja E; Rhee CM; Mehrotra R; Soohoo M; Brunelli SM; Kovesdy CP; Kalantar-Zadeh K · American journal of kidney diseases : the official journal of the National Kidney Foundation · 2016
    Cohort study9,359 participantsGeneral Health forMagnesium
  30. The effects of magnesium supplementation on abnormal uterine bleeding, alopecia, quality of life, and acne in women with polycystic ovary syndrome: a randomized clinical trial.
    Jaripur M; Ghasemi-Tehrani H; Askari G; Gholizadeh-Moghaddam M; Clark CCT; Rouhani MH · Reproductive biology and endocrinology : RB&E · 2022
    Randomized trial64 participantsGeneral Health forMagnesium
  31. 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
  32. 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
  33. 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
  34. Effectiveness of sodium bicarbonate and zinc chloride mouthwashes in the treatment of oral mucositis and quality of life in patients with cancer under chemotherapy.
    Mohammadi F; Oshvandi K; Kamallan SR; Khazaei S; Ranjbar H; Ahmadi-Motamayel F; Gillespie M; Jenabi E; Vafaei SY · Nursing open · 2022
    Randomized trial144 participantsGeneral Health forZinc
  35. Zinc supplementation in young children with acute diarrhea in India.
    Sazawal S; Black RE; Bhan MK; Bhandari N; Sinha A; Jalla S · The New England journal of medicine · 1995
    Randomized trial937 participantsGeneral Health forZinc
  36. Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age-Related Eye Disease Study: AREDS Report No. 13.
    Clemons TE; Kurinij N; Sperduto RD; AREDS Research Group · Archives of ophthalmology (Chicago, Ill. : 1960) · 2004
    Randomized trial4,753 participantsGeneral Health forZinc
  37. Effects of zinc and probiotic co-supplementation on inflammation, gastrointestinal symptoms, quality of life, and mood in irritable bowel syndrome patients.
    Rezazadegan M; Soheilipour M; Amani R · Scientific reports · 2026
    Randomized trial84 participantsGeneral Health forZinc
  38. Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trial.
    Siahbazi S; Behboudi-Gandevani S; Moghaddam-Banaem L; Montazeri A · The journal of obstetrics and gynaecology research · 2018
    Randomized trial142 participantsGeneral Health forZinc
  39. Quantitative Association Between Serum/Dietary Magnesium and Cardiovascular Disease/Coronary Heart Disease Risk: A Dose-Response Meta-analysis of Prospective Cohort Studies.
    Zhao L; Hu M; Yang L; Xu H; Song W; Qian Y; Zhao M · Journal of cardiovascular pharmacology · 2020
    Meta-analysis544,581 participants18 studies pooledHeart Health forMagnesium
  40. Effects of magnesium supplementation on improving hyperglycemia, hypercholesterolemia, and hypertension in type 2 diabetes: A pooled analysis of 24 randomized controlled trials.
    Xu L; Li X; Wang X; Xu M · Frontiers in nutrition · 2023
    Meta-analysis1,325 participants24 studies pooledHeart Health forMagnesium
  41. The effect of lowering blood pressure by magnesium supplementation in diabetic hypertensive adults with low serum magnesium levels: a randomized, double-blind, placebo-controlled clinical trial.
    Guerrero-Romero F; Rodríguez-Morán M · Journal of human hypertension · 2009
    Randomized trial82 participantsHeart Health forMagnesium
  42. Positive effects of magnesium supplementation in metabolic syndrome.
    Kisters S; Kisters K; Werner T; Vormann J; Tokmak F; Westhoff T; Gröber U; Predel HG; Reuter H · International journal of clinical pharmacology and therapeutics · 2024
    Randomized trial54 participantsHeart Health forMagnesium
  43. Comparative Efficacy of Nutraceuticals on Endothelial Function: A Systematic Review and Network Meta-Analysis.
    Norouzzadeh M; Rashedi MH; Mahdavi-Mazdeh G; Kosari A; Shahinfar H · Current atherosclerosis reports · 2026
    Meta-analysisHeart Health forMagnesium
  44. Oral potassium supplementation for management of essential hypertension: A meta-analysis of randomized controlled trials.
    Poorolajal J; Zeraati F; Soltanian AR; Sheikh V; Hooshmand E; Maleki A · PloS one · 2017
    Meta-analysis1,213 participants23 studies pooledHeart Health forPotassium
  45. Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study.
    O'Donnell M; Mente A; Rangarajan S; McQueen MJ; O'Leary N; Yin L; Liu X; Swaminathan S; Khatib R; Rosengren A; Ferguson J; Smyth A; Lopez-Jaramillo P; Diaz R; Avezum A; Lanas F; Ismail N; Yusoff K; Dans A; Iqbal R; Szuba A; Mohammadifard N; Oguz A; Yusufali AH; Alhabib KF; Kruger IM; Yusuf R; Chifamba J; Yeates K; Dagenais G; Wielgosz A; Lear SA; Teo K; Yusuf S; PURE Investigators · BMJ (Clinical research ed.) · 2019
    Cohort study103,570 participantsHeart Health forPotassium
  46. Effect of Potassium Supplementation on Endothelial Function: A Systematic Review and Meta-Analysis of Intervention Studies.
    D'Elia L; Cappuccio FP; Masulli M; La Fata E; Rendina D; Galletti F · Nutrients · 2023
    Meta-analysis332 participants5 studies pooledHeart Health forPotassium
  47. Effects of potassium supplementation on office, home, and 24-h blood pressure in patients with essential hypertension.
    Kawano Y; Minami J; Takishita S; Omae T · American journal of hypertension · 1999
    Randomized trial55 participantsHeart Health forPotassium
  48. 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
  49. 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
  50. 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
  51. 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
  52. 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
  53. Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: A systematic review and meta-analysis.
    Vlieg-Boerstra B; de Jong N; Meyer R; Agostoni C; De Cosmi V; Grimshaw K; Milani GP; Muraro A; Oude Elberink H; Pali-Schöll I; Roduit C; Sasaki M; Skypala I; Sokolowska M; van Splunter M; Untersmayr E; Venter C; O'Mahony L; Nwaru BI · Allergy · 2022
    Meta-analysis199,055 participants115 studies pooledImmunity forZinc
  54. Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and preschool children: a double-blind, controlled trial.
    Sazawal S; Black RE; Jalla S; Mazumdar S; Sinha A; Bhan MK · Pediatrics · 1998
    Randomized trial609 participantsImmunity forZinc
  55. A randomized controlled trial of zinc supplementation in the treatment of acute respiratory tract infection in Thai children.
    Rerksuppaphol S; Rerksuppaphol L · Pediatric reports · 2020
    Randomized trial64 participantsImmunity forZinc
  56. The effect of zinc and vitamin A supplementation on immune response in an older population.
    Fortes C; Forastiere F; Agabiti N; Fano V; Pacifici R; Virgili F; Piras G; Guidi L; Bartoloni C; Tricerri A; Zuccaro P; Ebrahim S; Perucci CA · Journal of the American Geriatrics Society · 1998
    Randomized trial136 participantsImmunity forZinc
  57. The role of specific nutrients in preventing immune system and blood cell disorders: an umbrella review.
    Vecchietti A; Strano P; Minutolo G; Grieco V; Cappuccio G; Granvillano G; Confalonieri L; Briganti GL; Raso E; Chimienti M; Pellegrini M; Mercogliano M; Spatari G; Lugli C; Urbano T; Lorenzon A · Journal of preventive medicine and hygiene · 2026
    Systematic review13 studies pooledImmunity forZinc
  58. 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
  59. 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
  60. 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
  61. 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
  62. 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
  63. 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
  64. 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
  65. Nutritional modulation of cataract.
    Weikel KA; Garber C; Baburins A; Taylor A · Nutrition reviews · 2014
    Narrative reviewVision Support forVitamin C
  66. 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
  67. 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
  68. Antioxidant vitamin and mineral supplements for age-related macular degeneration.
    Evans JR · The Cochrane database of systematic reviews · 2002
    Systematic review170 participants7 studies pooledVision Support forZinc
  69. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration.
    Evans JR; Lawrenson JG · The Cochrane database of systematic reviews · 2023
    Meta-analysis3,790 participants5 studies pooledVision Support forZinc
  70. Oral zinc in macular degeneration.
    Newsome DA; Swartz M; Leone NC; Elston RC; Miller E · Archives of ophthalmology (Chicago, Ill. : 1960) · 1988
    Randomized trial151 participantsVision Support forZinc
  71. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8.
    Age-Related Eye Disease Study Research Group · Archives of ophthalmology (Chicago, Ill. : 1960) · 2001
    Randomized trial3,640 participantsVision Support forZinc
  72. Effect of vitamin A and zinc supplementation on the nutriture of children in Northeast Thailand.
    Udomkesmalee E; Dhanamitta S; Sirisinha S; Charoenkiatkul S; Tuntipopipat S; Banjong O; Rojroongwasinkul N; Kramer TR; Smith JC · The American journal of clinical nutrition · 1992
    Randomized trial133 participantsVision Support forZinc