Vitamin C

Last Updated: November 20, 2023

Vitamin C, or ascorbic acid, is an essential vitamin and a very popular supplement due to its antioxidant properties, safety profile, and low price. Many people supplement with vitamin C because it is believed to reduce symptoms of the common cold.

Vitamin C is most often used for

What is vitamin C?

Vitamin C is a water-soluble essential vitamin that can be found in fruits and vegetables, especially citrus. Humans are unable to synthesize vitamin C from their bodies, so it must be acquired through dietary intake. Vitamin C is important for immune system function and is a powerful antioxidant. It also acts as a cofactor for collagen synthesis.[2]

What are vitamin C’s main benefits?

People often supplement with vitamin C when they have a cold. According to various studies, vitamin C may be effective in reducing the duration of a cold, but does not seem to reduce the frequency of colds in a population.[3][4] The available literature suggests that a dose ranging from 200 mg to 2,000 mg could be beneficial for reducing cold duration.

Often utilized for its antioxidant effects, vitamin C has been studied for its potential role in Alzheimer’s disease and cancer. Lower vitamin C levels are present in people with Alzheimer’s, even with adequate dietary intake.[5] It is thought that oxidative stress plays a major role in the pathogenesis of the disease, so vitamin C’s antioxidative effects could be beneficial.[6][7] In rodent studies, oral vitamin C was able to reduce oxidative and inflammatory biomarkers.[8] In recent cancer research, vitamin C was found to promote oxidative stress in cancer cells, leading to cytotoxic effects at high doses in mice.[9] While promising, further research and human studies are required to determine efficacy.

What are vitamin C’s main drawbacks?

In general, vitamin C supplementation at recommended doses seems to be safe. However, higher doses (3,000–10,000 mg) may cause diarrhea.[2] One meta-analysis noted an increased risk of dental erosion with chewable vitamin C tablets.[10] A rare but noteworthy possibility of nephrotoxicity after high dose administration has also been observed,[11][12] but this is unlikely to occur with typical oral supplementation.

How does vitamin C work?

Vitamin C acts as a cofactor for various enzymes, notably enzymes involved in collagen synthesis, and as an antioxidant.[13] It is an essential vitamin that humans cannot synthesize, so it must be acquired through dietary intake. Deficiencies in this vitamin results in scurvy, a condition caused by a lack of vitamin C.[13]

What else is Vitamin C known as?
Note that Vitamin C is also known as:
  • Ascorbic Acid
  • Ascorbate
  • L-ascorbic acid
Vitamin C should not be confused with:
Dosage information

According to the WHO, most adults need only 45 mg of vitamin C per day, but more recent research has shown this number to be too low. The minimum has been set at 75 mg for women and 90 mg for men in the U.S., and 95 mg for women and 110 mg for men in the E.U.

Moreover, a 2022 study using 110 mg as its starting number recommended adding 10 mg per 10 kg (22 lb) above 60 kg (132 lb) of body weight.[1]

Any of these numbers are easily attained through the diet, so supplementation of such low doses is usually unnecessary. Higher doses of vitamin C, up to 2,000 mg, are used to support the immune system (for athletes) or reduce the duration of the common cold.

Most studies on vitamin C prescribe one dose per day. The claim that taking 2,000 mg up to five times a day to optimally reduce cold symptoms is not sufficiently tested and requires more evidence.

Examine Database: Vitamin C
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Update History
2023-11-20 00:30:02

New meta analysis added

minor

We added data from a study testing vitamin c's effect on serum uric acid to our database.

Research Breakdown

References
  1. ^Anitra C Carr, Gladys Block, Jens LykkesfeldtEstimation of Vitamin C Intake Requirements Based on Body Weight: Implications for ObesityNutrients.(2022 Mar 31)
  2. ^Institute of Medicine (US) Panel on Dietary Antioxidants and Related CompoundsDietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids
  3. ^Hemilä H, Chalker EVitamin C for preventing and treating the common coldCochrane Database Syst Rev.(2013 Jan 31)
  4. ^Anderson TW, Suranyi G, Beaton GHThe effect on winter illness of large doses of vitamin C.Can Med Assoc J.(1974-Jul-06)
  5. ^Rivière S, Birlouez-Aragon I, Nourhashémi F, Vellas BLow plasma vitamin C in Alzheimer patients despite an adequate diet.Int J Geriatr Psychiatry.(1998-Nov)
  6. ^Christen YOxidative stress and Alzheimer disease.Am J Clin Nutr.(2000-Feb)
  7. ^Heo JH, Hyon-Lee , Lee KMThe possible role of antioxidant vitamin C in Alzheimer's disease treatment and prevention.Am J Alzheimers Dis Other Demen.(2013-Mar)
  8. ^Rosales-Corral S, Tan DX, Reiter RJ, Valdivia-Velázquez M, Martínez-Barboza G, Acosta-Martínez JP, Ortiz GGOrally administered melatonin reduces oxidative stress and proinflammatory cytokines induced by amyloid-beta peptide in rat brain: a comparative, in vivo study versus vitamin C and E.J Pineal Res.(2003-Sep)
  9. ^Chen Q, Espey MG, Sun AY, Pooput C, Kirk KL, Krishna MC, Khosh DB, Drisko J, Levine MPharmacologic doses of ascorbate act as a prooxidant and decrease growth of aggressive tumor xenografts in miceProc Natl Acad Sci U S A.(2008 Aug 12)
  10. ^Li H, Zou Y, Ding GDietary factors associated with dental erosion: a meta-analysisPLoS One.(2012)
  11. ^Lawton JM, Conway LT, Crosson JT, Smith CL, Abraham PAAcute oxalate nephropathy after massive ascorbic acid administration.Arch Intern Med.(1985-May)
  12. ^Wong K, Thomson C, Bailey RR, McDiarmid S, Gardner JAcute oxalate nephropathy after a massive intravenous dose of vitamin C.Aust N Z J Med.(1994-Aug)
  13. ^Traber MG, Stevens JFVitamins C and E: beneficial effects from a mechanistic perspective.Free Radic Biol Med.(2011-Sep-01)
Examine Database References
  1. HbA1c - Mason SA, Della Gatta PA, Snow RJ, Russell AP, Wadley GDAscorbic acid supplementation improves skeletal muscle oxidative stress and insulin sensitivity in people with type 2 diabetes: Findings of a randomized controlled studyFree Radic Biol Med.(2016 Apr)
  2. HbA1c - Siavash M, Amini MVitamin C may have similar beneficial effects to Gemfibrozil on serum high-density lipoprotein-cholesterol in type 2 diabetic patientsJ Res Pharm Pract.(2014 Jul)
  3. HbA1c - Dakhale GN, Chaudhari HV, Shrivastava MSupplementation of vitamin C reduces blood glucose and improves glycosylated hemoglobin in type 2 diabetes mellitus: a randomized, double-blind studyAdv Pharmacol Sci.(2011)
  4. HbA1c - Bishop N, Schorah CJ, Wales JKThe effect of vitamin C supplementation on diabetic hyperlipidaemia: a double blind, crossover studyDiabet Med.(1985 Mar)
  5. HbA1c - JAYESH K BHATT, SABIN THOMAS, NANJAN MJEFFECT OF ORAL SUPPLEMENTATION OF VITAMIN C ON GLYCEMIC CONTROL AND LIPID PROFILE IN PATIENTS WITH TYPE 2 DIABETES MELLITUSInternational Journal of Pharmacy and Pharmaceutical Sciences.()
  6. HbA1c - Klein F, Juhl B, Christiansen JSUnchanged renal haemodynamics following high dose ascorbic acid administration in normoalbuminuric IDDM patientsScand J Clin Lab Invest.(1995 Feb)
  7. HbA1c - Camargo JL, Stifft J, Gross JLThe effect of aspirin and vitamins C and E on HbA1c assaysClin Chim Acta.(2006 Oct)
  8. HbA1c - Mason SA, Rasmussen B, van Loon LJC, Salmon J, Wadley GDAscorbic acid supplementation improves postprandial glycaemic control and blood pressure in individuals with type 2 diabetes: Findings of a randomized cross-over trialDiabetes Obes Metab.(2019 Mar)
  9. HbA1c - Mahmoudabadi MM, Djalali M, Djazayery SA, Keshavarz SA, Eshraghian MR, Yaraghi AA, Askari G, Ghiasvand R, Zarei MEffects of eicosapentaenoic acid and vitamin C on glycemic indices, blood pressure, and serum lipids in type 2 diabetic Iranian malesJ Res Med Sci.(2011 Mar)
  10. Triglycerides - Ellulu MS, Rahmat A, Patimah I, Khaza'ai H, Abed YEffect of vitamin C on inflammation and metabolic markers in hypertensive and/or diabetic obese adults: a randomized controlled trialDrug Des Devel Ther.(2015 Jul 1)
  11. Triglycerides - Gutierrez AD, Duran-Valdez E, Robinson I, de Serna DG, Schade DSDoes short-term vitamin C reduce cardiovascular risk in type 2 diabetes?Endocr Pract.(2013 Sep-Oct)
  12. Triglycerides - Tousoulis D, Antoniades C, Vasiliadou C, Kourtellaris P, Koniari K, Marinou K, Charakida M, Ntarladimas I, Siasos G, Stefanadis CEffects of atorvastatin and vitamin C on forearm hyperaemic blood flow, asymmentrical dimethylarginine levels and the inflammatory process in patients with type 2 diabetes mellitusHeart.(2007 Feb)
  13. Triglycerides - Mazloom Z, Hejazi N, Dabbaghmanesh MH, Tabatabaei HR, Ahmadi A, Ansar HEffect of vitamin C supplementation on postprandial oxidative stress and lipid profile in type 2 diabetic patientsPak J Biol Sci.(2011 Oct 1)
  14. Low-density lipoprotein (LDL) - Ghaffari et alThe effects of vitamin C on diabetic patients Pharm Lett.()
  15. Blood glucose - Chen H, Karne RJ, Hall G, Campia U, Panza JA, Cannon RO 3rd, Wang Y, Katz A, Levine M, Quon MJHigh-dose oral vitamin C partially replenishes vitamin C levels in patients with Type 2 diabetes and low vitamin C levels but does not improve endothelial dysfunction or insulin resistanceAm J Physiol Heart Circ Physiol.(2006 Jan)
  16. HbA1c - Ashor AW, Werner AD, Lara J, Willis ND, Mathers JC, Siervo MEffects of vitamin C supplementation on glycaemic control: a systematic review and meta-analysis of randomised controlled trialsEur J Clin Nutr.(2017 Dec)
  17. Exercise-Induced Oxidation - Nakhostin-Roohi B, Babaei P, Rahmani-Nia F, Bohlooli SEffect of vitamin C supplementation on lipid peroxidation, muscle damage and inflammation after 30-min exercise at 75% VO2maxJ Sports Med Phys Fitness.(2008 Jun)
  18. Exercise-Induced Oxidation - Bryant RJ, Ryder J, Martino P, Kim J, Craig BWEffects of vitamin E and C supplementation either alone or in combination on exercise-induced lipid peroxidation in trained cyclistsJ Strength Cond Res.(2003 Nov)
  19. Cortisol - Davison G, Gleeson MThe effect of 2 weeks vitamin C supplementation on immunoendocrine responses to 2.5 h cycling exercise in manEur J Appl Physiol.(2006 Jul)
  20. Cortisol - Glen Davison, Michael GleesonInfluence of acute vitamin C and/or carbohydrate ingestion on hormonal, cytokine, and immune responses to prolonged exerciseInt J Sport Nutr Exerc Metab.(2005 Oct)
  21. Resistin - Bo S, Ciccone G, Durazzo M, Gambino R, Massarenti P, Baldi I, Lezo A, Tiozzo E, Pauletto D, Cassader M, Pagano GEfficacy of antioxidant treatment in reducing resistin serum levels: a randomized studyPLoS Clin Trials.(2007 May 4)
  22. Inflammation - Colby JA, Chen WT, Baker WL, Coleman CI, Reinhart K, Kluger J, White CMEffect of ascorbic acid on inflammatory markers after cardiothoracic surgeryAm J Health Syst Pharm.(2011 Sep 1)
  23. Blood Flow - Sergio De Marchi, Manlio Prior, Anna Rigoni, Sara Zecchetto, Fanny Rulfo, Enrico ArosioAscorbic acid prevents vascular dysfunction induced by oral glucose load in healthy subjectsEur J Intern Med.(2012 Jan)
  24. General Oxidation - Kuiper HC, Bruno RS, Traber MG, Stevens JFVitamin C supplementation lowers urinary levels of 4-hydroperoxy-2-nonenal metabolites in humansFree Radic Biol Med.(2011 Apr 1)
  25. General Oxidation - Retana-Ugalde R, Casanueva E, Altamirano-Lozano M, González-Torres C, Mendoza-Núñez VMHigh dosage of ascorbic acid and alpha-tocopherol is not useful for diminishing oxidative stress and DNA damage in healthy elderly adultsAnn Nutr Metab.(2008)
  26. Lipid Peroxidation - Johnston CS, Dancho CL, Strong GMOrange juice ingestion and supplemental vitamin C are equally effective at reducing plasma lipid peroxidation in healthy adult womenJ Am Coll Nutr.(2003 Dec)
  27. C-Reactive Protein (CRP) - Block G, Jensen CD, Dalvi TB, Norkus EP, Hudes M, Crawford PB, Holland N, Fung EB, Schumacher L, Harmatz PVitamin C treatment reduces elevated C-reactive proteinFree Radic Biol Med.(2009 Jan 1)
  28. Blood glucose - Johnston CS, Yen MFMegadose of vitamin C delays insulin response to a glucose challenge in normoglycemic adultsAm J Clin Nutr.(1994 Nov)
  29. Protection from Smoking - Fuller CJ, May MA, Martin KJThe effect of vitamin E and vitamin C supplementation on LDL oxidizability and neutrophil respiratory burst in young smokersJ Am Coll Nutr.(2000 Jun)
  30. Exercise Adaptations - Ristow M, Zarse K, Oberbach A, Klöting N, Birringer M, Kiehntopf M, Stumvoll M, Kahn CR, Blüher MAntioxidants prevent health-promoting effects of physical exercise in humansProc Natl Acad Sci U S A.(2009 May 26)
  31. DNA Damage - Guarnieri S, Riso P, Porrini MOrange juice vs vitamin C: effect on hydrogen peroxide-induced DNA damage in mononuclear blood cellsBr J Nutr.(2007 Apr)
  32. Mineral Bioaccumulation - Calabrese EJ, Stoddard A, Leonard DA, Dinardi SRThe effects of vitamin C supplementation on blood and hair levels of cadmium, lead, and mercuryAnn N Y Acad Sci.(1987)
  33. Glycemic Control - Yfanti C, Nielsen AR, Akerström T, Nielsen S, Rose AJ, Richter EA, Lykkesfeldt J, Fischer CP, Pedersen BKEffect of antioxidant supplementation on insulin sensitivity in response to endurance exercise trainingAm J Physiol Endocrinol Metab.(2011 May)
  34. Upper Respiratory Tract Infection Symptoms - Anderson TW, Reid DB, Beaton GHVitamin C and the common cold: a double-blind trialCan Med Assoc J.(1972 Sep 23)
  35. Upper Respiratory Tract Infection Symptoms - Charleston SS, Clegg KMAscorbic acid and the common coldLancet.(1972 Jun 24)
  36. Upper Respiratory Tract Infection Symptoms - Van Straten M, Josling PPreventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled surveyAdv Ther.(2002 May-Jun)
  37. Upper Respiratory Tract Infection Symptoms - Carson M, Cox H, Corbett M, Pollitt NVitamin C and the common coldJ Soc Occup Med.(1975 Jul)
  38. Upper Respiratory Tract Infection Symptoms - Anderson TW, Beaton GH, Corey P, Spero LWinter illness and vitamin C: the effect of relatively low dosesCan Med Assoc J.(1975 Apr 5)
  39. Upper Respiratory Tract Infection Symptoms - Karlowski TR, Chalmers TC, Frenkel LD, Kapikian AZ, Lewis TL, Lynch JMAscorbic acid for the common cold. A prophylactic and therapeutic trialJAMA.(1975 Mar 10)
  40. Upper Respiratory Tract Infection Symptoms - Dahlberg G, Engel A, Rydin HThe Value of Ascorbic Acid as a Prophylactic against Common ColdsActa Medica Scandinavica.()
  41. Upper Respiratory Tract Infection Symptoms - Constantini NW, Dubnov-Raz G, Eyal BB, Berry EM, Cohen AH, Hemilä HThe effect of vitamin C on upper respiratory infections in adolescent swimmers: a randomized trialEur J Pediatr.(2011 Jan)
  42. Upper Respiratory Tract Infection Symptoms - Miller JZ, Nance WE, Norton JA, Wolen RL, Griffith RS, Rose RJTherapeutic effect of vitamin C. A co-twin control studyJAMA.(1977 Jan 17)
  43. Upper Respiratory Tract Infection Symptoms - Sabiston BH, Radomski MWHealth problems and vitamin C in Canadian northern military operations.()
  44. Upper Respiratory Tract Infection Symptoms - Elwood PC, Hughes SJ, Leger ASA randomized controlled trial of the therapeutic effect of vitamin C in the common coldPractitioner.(1977 Jan)
  45. Upper Respiratory Tract Infection Symptoms - Carr AB, Einstein R, Lai LY, Martin NG, Starmer GAVitamin C and the common cold: a second MZ Cotwin control studyActa Genet Med Gemellol (Roma).(1981)
  46. Upper Respiratory Tract Infection Symptoms - Walker GH, Bynoe ML, Tyrrell DATrial of ascorbic acid in prevention of coldsBr Med J.(1967 Mar 11)
  47. Upper Respiratory Tract Infection Symptoms - Audera C, Patulny RV, Sander BH, Douglas RMMega-dose vitamin C in treatment of the common cold: a randomised controlled trialMed J Aust.(2001 Oct 1)
  48. Upper Respiratory Tract Infection Symptoms - Lewis TL, Karlowski TR, Kapikian AZ, Lynch JM, Shaffer GW, George DAA controlled clinical trial of ascorbic acid for the common coldAnn N Y Acad Sci.(1975 Sep 30)
  49. Upper Respiratory Tract Infection Symptoms - Gorton HC, Jarvis KThe effectiveness of vitamin C in preventing and relieving the symptoms of virus-induced respiratory infectionsJ Manipulative Physiol Ther.(1999 Oct)
  50. Upper Respiratory Tract Infection Symptoms - Pitt HA, Costrini AMVitamin C prophylaxis in marine recruitsJAMA.(1979 Mar 2)
  51. Upper Respiratory Tract Infection Symptoms - Clegg KM, Macdonald JML-Ascorbic acid and D-isoascorbic acid in a common cold surveyAm J Clin Nutr.(1975 Sep)
  52. Upper Respiratory Tract Infection Symptoms - Elwood PC, Lee HP, St Leger AS, Baird M, Howard ANA randomized controlled trial of vitamin C in the prevention and amelioration of the common coldBr J Prev Soc Med.(1976 Sep)
  53. Upper Respiratory Tract Infection Symptoms - Schwartz AR, Togo Y, Hornick RB, Tominaga S, Gleckman RAEvaluation of the efficacy of ascorbic acid in prophylaxis of induced rhinovirus 44 infection in manJ Infect Dis.(1973 Oct)
  54. Upper Respiratory Tract Infection Symptoms - Ludvigsson J, Hansson LO, Tibbling GVitamin C as a preventive medicine against common colds in childrenScand J Infect Dis.(1977)
  55. Upper Respiratory Tract Infection Symptoms - FRANZ WL, HEYL HL, SANDS GWBlood ascorbic acid level in bioflavonoid and ascorbic acid therapy of common coldJ Am Med Assoc.(1956 Nov 24)
  56. Upper Respiratory Tract Infection Symptoms - Hunt C, Chakravorty NK, Annan G, Habibzadeh N, Schorah CJThe clinical effects of vitamin C supplementation in elderly hospitalised patients with acute respiratory infectionsInt J Vitam Nutr Res.(1994)
  57. Upper Respiratory Tract Infection Symptoms - Cowdan D, Diehl H, Baker ABVitamins For The Prevention Of ColdsJAMA.()
  58. Upper Respiratory Tract Infection Symptoms - Tyrrell DA, Craig JW, Meada TW, White TA trial of ascorbic acid in the treatment of the common coldBr J Prev Soc Med.(1977 Sep)
  59. Common Cold Symptoms - Ineffectiveness of vitamin C in treating coryza.Practitioner.(1968-Mar)
  60. Upper Respiratory Tract Infection Risk - Kim TK, Lim HR, Byun JSVitamin C supplementation reduces the odds of developing a common cold in Republic of Korea Army recruits: randomised controlled trialBMJ Mil Health.(2020 Mar 5)
  61. Upper Respiratory Tract Infection Risk - Hunt C, Chakravorty NK, Annan GThe clinical and biochemical effects of vitamin C supplementation in short-stay hospitalized geriatric patientsInt J Vitam Nutr Res.(1984)
  62. Total cholesterol - Knab AM, Shanely RA, Henson DA, Jin F, Heinz SA, Austin MD, Nieman DCInfluence of quercetin supplementation on disease risk factors in community-dwelling adultsJ Am Diet Assoc.(2011 Apr)
  63. Interferon Gamma - Nieman DC, Henson DA, McAnulty SR, McAnulty L, Swick NS, Utter AC, Vinci DM, Opiela SJ, Morrow JDInfluence of vitamin C supplementation on oxidative and immune changes after an ultramarathonJ Appl Physiol (1985).(2002 May)
  64. Cortisol - Carrillo AE, Murphy RJ, Cheung SSVitamin C supplementation and salivary immune function following exercise-heat stressInt J Sports Physiol Perform.(2008 Dec)
  65. Cortisol - Palmer FM, Nieman DC, Henson DA, McAnulty SR, McAnulty L, Swick NS, Utter AC, Vinci DM, Morrow JDInfluence of vitamin C supplementation on oxidative and salivary IgA changes following an ultramarathonEur J Appl Physiol.(2003 Mar)
  66. Upper Respiratory Tract Infection Risk - Baird IM, Hughes RE, Wilson HK, Davies JE, Howard ANThe effects of ascorbic acid and flavonoids on the occurrence of symptoms normally associated with the common coldAm J Clin Nutr.(1979 Aug)
  67. Inflammation - Thompson D, Bailey DM, Hill J, Hurst T, Powell JR, Williams CProlonged vitamin C supplementation and recovery from eccentric exerciseEur J Appl Physiol.(2004 Jun)
  68. Muscle Damage - Bryer SC, Goldfarb AHEffect of high dose vitamin C supplementation on muscle soreness, damage, function, and oxidative stress to eccentric exerciseInt J Sport Nutr Exerc Metab.(2006 Jun)
  69. Muscle Damage - Theodorou AA, Nikolaidis MG, Paschalis V, Koutsias S, Panayiotou G, Fatouros IG, Koutedakis Y, Jamurtas AZNo effect of antioxidant supplementation on muscle performance and blood redox status adaptations to eccentric trainingAm J Clin Nutr.(2011 Jun)
  70. Aerobic Exercise Metrics - Roberts LA, Beattie K, Close GL, Morton JPVitamin C consumption does not impair training-induced improvements in exercise performanceInt J Sports Physiol Perform.(2011 Mar)
  71. Aerobic Exercise Metrics - Ataka S, Tanaka M, Nozaki S, Mizuma H, Mizuno K, Tahara T, Sugino T, Shirai T, Kajimoto Y, Kuratsune H, Kajimoto O, Watanabe YEffects of Applephenon and ascorbic acid on physical fatigueNutrition.(2007 May)
  72. Cortisol - Pirbudak L, Balat O, Cekmen M, Ugur MG, Aygün S, Oner UEffect of ascorbic acid on surgical stress response in gynecologic surgeryInt J Clin Pract.(2004 Oct)
  73. Upper Respiratory Tract Infection Risk - Gormly PJMegadosage of ascorbic acid in an Antarctic expeditionBr J Nutr.(1977 Mar)
  74. Upper Respiratory Tract Infection Risk - Coulehan JL, Eberhard S, Kapner L, Taylor F, Rogers K, Garry PVitamin C and acute illness in Navajo school childrenN Engl J Med.(1976 Oct 28)
  75. Upper Respiratory Tract Infection Risk - Himmelstein S, Robergs R, Koehler K, Lewis S, Qualls CVitamin C supplementation and upper respiratory tract infections in marathon runnersJ Exerc Physiol Online.()
  76. Upper Respiratory Tract Infection Risk - Peters EM, Goetzsche JM, Grobbelaar B, Noakes TDVitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runnersAm J Clin Nutr.(1993 Feb)
  77. Plasma Vitamin C - Davison GW, Ashton T, George L, Young IS, McEneny J, Davies B, Jackson SK, Peters JR, Bailey DMMolecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trialDiabetologia.(2008 Nov)
  78. General Oxidation - Van Hoydonck PG, Schouten EG, Manuel-Y-Keenoy B, van Campenhout A, Hoppenbrouwers KP, Temme EHDoes vitamin C supplementation influence the levels of circulating oxidized LDL, sICAM-1, sVCAM-1 and vWF-antigen in healthy male smokersEur J Clin Nutr.(2004 Dec)
  79. Blood Flow - Fernandes PR, Lira FA, Borba VV, Costa MJ, Trombeta IC, Santos Mdo S, Santos Ada CVitamin C restores blood pressure and vasodilator response during mental stress in obese childrenArq Bras Cardiol.(2011 Jun)
  80. Blood Flow - Mullan BA, Ennis CN, Fee HJ, Young IS, McCance DRPretreatment with intravenous ascorbic acid preserves endothelial function during acute hyperglycaemia (R1)Clin Exp Pharmacol Physiol.(2005 May-Jun)
  81. Blood Flow - Stamatelopoulos KS, Lekakis JP, Papamichael CM, Papaioannou TG, Cimboneriou A, Stamatelopoulos SFOral administration of ascorbic acid attenuates endothelial dysfunction after short-term cigarette smokingInt J Vitam Nutr Res.(2003 Nov)
  82. Blood glucose - Pleiner J, Schaller G, Mittermayer F, Bayerle-Eder M, Roden M, Wolzt MFFA-induced endothelial dysfunction can be corrected by vitamin CJ Clin Endocrinol Metab.(2002 Jun)
  83. Pre-Eclampsia Risk - Kalpdev A, Saha SC, Dhawan VVitamin C and E supplementation does not reduce the risk of superimposed PE in pregnancyHypertens Pregnancy.(2011)
  84. Anti-Oxidant Enzyme Profile - Ruiz-Ramos M, Vargas LA, Fortoul Van der Goes TI, Cervantes-Sandoval A, Mendoza-Nunez VMSupplementation of ascorbic acid and alpha-tocopherol is useful to preventing bone loss linked to oxidative stress in elderlyJ Nutr Health Aging.(2010 Jun)
  85. Bone Mineral Density - Chuin A, Labonté M, Tessier D, Khalil A, Bobeuf F, Doyon CY, Rieth N, Dionne IJEffect of antioxidants combined to resistance training on BMD in elderly women: a pilot studyOsteoporos Int.(2009 Jul)
  86. Body Fat - Knab AM, Shanely RA, Jin F, Austin MD, Sha W, Nieman DCQuercetin with vitamin C and niacin does not affect body mass or compositionAppl Physiol Nutr Metab.(2011 Jun)
  87. Bacterial Vaginosis Symptoms - Petersen EE, Genet M, Caserini M, Palmieri REfficacy of vitamin C vaginal tablets in the treatment of bacterial vaginosis: a randomised, double blind, placebo controlled clinical trialArzneimittelforschung.(2011)
  88. General Oxidation - Monika Lagowska-Lenard, Zbigniew Stelmasiak, Halina Bartosik-PsujekInfluence of vitamin C on markers of oxidative stress in the earliest period of ischemic strokePharmacol Rep.(Jul-Aug 2010)
  89. Upper Respiratory Tract Infection Risk - Coulehan JL, Reisinger KS, Rogers KD, Bradley DWVitamin C prophylaxis in a boarding schoolN Engl J Med.(1974 Jan 3)
  90. Depression Symptoms - Brody SHigh-dose ascorbic acid increases intercourse frequency and improves mood: a randomized controlled clinical trialBiol Psychiatry.(2002 Aug 15)
  91. Cataract Risk - Christen WG, Glynn RJ, Sesso HD, Kurth T, MacFadyen J, Bubes V, Buring JE, Manson JE, Gaziano JMAge-related cataract in a randomized trial of vitamins E and C in menArch Ophthalmol.(2010 Nov)
  92. Triglycerides - Kim MK, Sasaki S, Sasazuki S, Okubo S, Hayashi M, Tsugane SLong-term vitamin C supplementation has no markedly favourable effect on serum lipids in middle-aged Japanese subjectsBr J Nutr.(2004 Jan)
  93. Charcot Marie Tooth Disease Symptoms - Pareyson D, Reilly MM, Schenone A, Fabrizi GM, Cavallaro T, Santoro L, Vita G, Quattrone A, Padua L, Gemignani F, Visioli F, Laurà M, Radice D, Calabrese D, Hughes RA, Solari A; CMT-TRIAAL; CMT-TRAUK groupsAscorbic acid in Charcot-Marie-Tooth disease type 1A (CMT-TRIAAL and CMT-TRAUK): a double-blind randomised trialLancet Neurol.(2011 Apr)
  94. Uric Acid - Han-Yao Huang, Lawrence J Appel, Michael J Choi, Allan C Gelber, Jeanne Charleston, Edward P Norkus, Edgar R Miller 3rdThe effects of vitamin C supplementation on serum concentrations of uric acid: results of a randomized controlled trialArthritis Rheum.(2005 Jun)
  95. Uric Acid - Xin-Xin Liu, Xiao-Xue Wang, Ling-Ling CuiAssociation between Oral vitamin C supplementation and serum uric acid: A meta-analysis of randomized controlled trialsComplement Ther Med.(2021 Aug)
  96. COVID-19 Severity - Saeidreza JamaliMoghadamSiahkali, Besharat Zarezade, Sogol Koolaji, SeyedAhmad SeyedAlinaghi, Abolfazl Zendehdel, Mohammad Tabarestani, Ehsan Sekhavati Moghadam, Ladan Abbasian, Seyed Ali Dehghan Manshadi, Mohamadreza Salehi, Malihe Hasannezhad, Sara Ghaderkhani, Mohsen Meidani, Faeze Salahshour, Fatemeh Jafari, Navid Manafi, Fereshteh GhiasvandSafety and effectiveness of high-dose vitamin C in patients with COVID-19: a randomized open-label clinical trialEur J Med Res.(2021 Feb 11)
  97. COVID-19 Severity - Suma Thomas, Divyang Patel, Barbara Bittel, Kathy Wolski, Qiuqing Wang, Anirudh Kumar, Zachary J Il'Giovine, Reena Mehra, Carla McWilliams, Steve E Nissen, Milind Y DesaiEffect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction Among Ambulatory Patients With SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical TrialJAMA Netw Open.(2021 Feb 1)
  98. Weight - Huck CJ, Johnston CS, Beezhold BL, Swan PDVitamin C status and perception of effort during exercise in obese adults adhering to a calorie-reduced dietNutrition.(2012 Jun 5)
  99. Subjective Well-Being - Zhang M, Robitaille L, Eintracht S, Hoffer LJVitamin C provision improves mood in acutely hospitalized patientsNutrition.(2011 May)
  100. Sperm Quality - Vani K, Kurakula M, Syed R, Alharbi KClinical relevance of vitamin C among lead-exposed infertile menGenet Test Mol Biomarkers.(2012 Sep)
  101. Microcirculation - Stewart JM, Ocon AJ, Medow MSAscorbate improves circulation in postural tachycardia syndromeAm J Physiol Heart Circ Physiol.(2011 Sep)
  102. Spontaneous Birth Risk - Hauth JC, Clifton RG, Roberts JM, Spong CY, Myatt L, Leveno KJ, Pearson GD, Varner MW, Thorp JM Jr, Mercer BM, Peaceman AM, Ramin SM, Sciscione A, Harper M, Tolosa JE, Saade G, Sorokin Y, Anderson GB; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU)Vitamin C and E supplementation to prevent spontaneous preterm birth: a randomized controlled trialObstet Gynecol.(2010 Sep)
  103. Heart Rate - Gomes ME, El Messaoudi S, Lenders JW, Bellersen L, Verheugt FW, Smits P, Tack CJHigh dose ascorbic acid does not reverse central sympathetic overactivity in chronic heart failureJ Clin Pharm Ther.(2011 Oct)
  104. Gout Symptoms - Stephen P Juraschek, J Michael Gaziano, Robert J Glynn, Natalya Gomelskaya, Vadim Y Bubes, Julie E Buring, Robert H Shmerling, Howard D SessoEffects of vitamin C supplementation on gout risk: results from the physicians' health study II trialAm J Clin Nutr.(2022 May 16)