Analgesics..
Antiandrogens..
Bromhexine
Budesonide
Cannabidiol
Colchicine
Conv. Plasma
Curcumin
Ensovibep
Famotidine
Favipiravir
Fluvoxamine
Hydroxychlor..
Iota-carragee..
Ivermectin
Lactoferrin
Lifestyle..
Melatonin
Metformin
Molnupiravir
Monoclonals..
Nigella Sativa
Nitazoxanide
Nitric Oxide
Paxlovid
Peg.. Lambda
Povidone-Iod..
Quercetin
Remdesivir
Vitamins..
Zinc

Other
Feedback
Home
Home   COVID-19 treatment studies for Vitamin C  COVID-19 treatment studies for Vitamin C  C19 studies: Vitamin C  Vitamin C   Select treatmentSelect treatmentTreatmentsTreatments
Melatonin Meta
Bromhexine Meta Metformin Meta
Budesonide Meta Molnupiravir Meta
Cannabidiol Meta
Colchicine Meta Nigella Sativa Meta
Conv. Plasma Meta Nitazoxanide Meta
Curcumin Meta Nitric Oxide Meta
Ensovibep Meta Paxlovid Meta
Famotidine Meta Peg.. Lambda Meta
Favipiravir Meta Povidone-Iod.. Meta
Fluvoxamine Meta Quercetin Meta
Hydroxychlor.. Meta Remdesivir Meta
Iota-carragee.. Meta
Ivermectin Meta Zinc Meta
Lactoferrin Meta

Other Treatments Global Adoption
 
Vitamin C COVID-19 studies. The treatment regimen varies widely across studies and may be high-dose IV vitamin C. Recent:
Özgülteki
Mosadegh
Kumar
Jang
Foshati
Aldwihi
Sinnberg.
Vitamin C has been officially adopted for early treatment in all or part of 3 countries. Submit updates/corrections.
Oct 4
Covid Analysis (Preprint) (meta analysis) Vitamin C for COVID-19: real-time meta analysis of 53 studies
Statistically significant improvements are seen for mortality, ICU admission, hospitalization, and recovery. 17 studies from 17 independent teams in 11 different countries show statistically significant improvements in isolation (11 for..
Sep 22
Özgülteki̇n et al., Kastamonu Medical Journal, doi:10.51271/KMJ-0059 The effect of high-dose vitamin C on renal functions in COVID–19 patients
5% higher mortality [p=1]. Retrospective 43 ICU patients in Turkey, 21 treated with vitamin C, showing no significant difference in mortality and increased renal failure. Treatment included stage 1 AKI patients. Vitamin C 45-50 g/day for 5 days.
Sep 19
Mosadegh et al., Microbial Pathogenesis, doi:10.1016/j.micpath.2022.105792 The effect of Nutrition Bio-shield superfood (NBS) on disease severity and laboratory biomarkers in patients with COVID-19: A randomized clinical trial
61% lower mortality [p=0.002] and 28% shorter hospitalization [p=0.001]. RCT 70 hospitalized severe COVID-19 patients in Iran, showing lower mortality and improved clinical markers with treatment combining vitamins A, B1–B3, B5, B6, B9, C, D, K, and magnesium, potassium, phosphorus, sulfur, manganese, calcium,..
Sep 2
Foshati et al., Food Science & Nutrition, doi:10.1002/fsn3.3034 Antioxidants and clinical outcomes of patients with coronavirus disease 2019: A systematic review of observational and interventional studies
Systematic review showing that vitamin C, vitamin D, selenium, and zinc can improve COVID-19 clinical outcomes.
Aug 30
Kumar et al., Journal of Family Medicine and Primary Care, doi:10.4103/jfmpc.jfmpc_2437_21 Efficacy of intravenous vitamin C in management of moderate and severe COVID-19: A double blind randomized placebo controlled trial
23% lower mortality [p=0.6] and 21% lower ventilation [p=0.6]. RCT 60 ICU patients in India, showing no significant difference in outcomes with vitamin C. Mortality was lower in the vitamin C arm despite having more severe cases at baseline (87% vs. 67%). 1 gram intravenous vitamin C 8 hourly for fou..
Aug 16
Loucera et al., medRxiv, doi:10.1101/2022.08.14.22278751 (Preprint) Real-world evidence with a retrospective cohort of 15,968 Andalusian COVID-19 hospitalized patients suggests 21 new effective treatments and one drug that increases death risk
28% lower mortality [p=0.002]. Retrospective 15,968 COVID-19 hospitalized patients in Spain, showing lower mortality with existing use of several medications including metformin, HCQ, aspirin, vitamin D, vitamin C, and budesonide.
Aug 15
Sinnberg et al., Antioxidants, doi:10.3390/antiox11081580 Vitamin C Deficiency in Blood Samples of COVID-19 Patients
42% lower mortality [p=0.38], 41% lower ventilation [p=0.17], and 61% lower hospitalization [p=0.05]. Analysis of 74 COVID-19 patients and 8 controls in Germany, showing low vitamin C levels associated with mortality. There was no significant difference for vitamin A, D, or E levels. Very few group details are provided, for example the ag..
Aug 8
Bhowmik et al., Health Science Reports, doi:10.1002/hsr2.762 (meta analysis) Impact of high-dose vitamin C on the mortality, severity, and duration of hospital stay in COVID-19 patients: A meta-analysis
46% lower mortality [p<0.0001]. Meta analysis of 15 studies with 2,125 COVID-19 patients showing significantly lower mortality with high-dose vitamin C.
Jul 27
Fogleman et al., The Journal of the American Board of Family Medicine, doi:10.3122/jabfm.2022.04.210529 A Pilot of a Randomized Control Trial of Melatonin and Vitamin C for Mild-to-Moderate COVID-19
4% improved recovery [p=0.83]. Early terminated low-risk patient RCT with 32 low-dose vitamin C, 32 melatonin, and 34 placebo patients, showing faster resolution of symptoms with melatonin in spline regression analysis, and no significant difference for vitamin C. All ..
Jul 19
Izzo et al., Pharmacological Research, doi:10.1016/j.phrs.2022.106360 Combining L-Arginine with Vitamin C Improves Long-COVID Symptoms: The Nationwide Multicenter LINCOLN Study
41% improved recovery [p<0.0001]. Long COVID trial comparing L-arginine + vitamin C with multivitamin treatment (vitamin B1, B2, B6, B12, nicotinamide, folic acid, pantothenic acid), showing significant improvement in symptoms with L-arginine + vitamin C treatment.
Jul 15
Zuo et al., bioRxiv, doi:10.1101/2022.07.14.499651 (Preprint) Vitamin C is an efficient natural product for prevention of SARS-CoV-2 infection by targeting ACE2 in both cell and in vivo mouse models
In Vitro and mouse study showing vitamin C inhibits SARS-CoV-2. Vitamin C lowered ACE2 protein levels in a dose-dependent manner at a concentration of 1-10mM in both cell and humanized ACE2 mouse models.
Jun 16
Ortore et al., International Journal of Translational Medicine, doi:10.3390/ijtm2020022 Evaluation of the Clinical Effects of an Antiviral, Immunostimulant and Antioxidant Phytotherapy in Patients Suffering from COVID-19 Infection: An Observational Pilot Study
Retrospective case series of 240 patients in Italy in 2020, up to 96 years old, showing no mortality and 1.6% hospitalization with early treatment including vitamin C, quercetin, and green tea and red wine polyphenols. The formulation was..
Jun 7
Usanma Koban et al., Bratislava Medical Journal, doi:10.4149/BLL_2022_082 The factors affecting the prolonged PCR positivity in COVID-19 patients
33% improved viral clearance [p=0.73]. Retrospective 126 patients in Turkey, showing no significant difference in PCR+ at day 14 with vitamin C treatment.
May 30
Kumar et al., Cureus, doi:10.7759/cureus.25467 Efficacy and Safety of Aspirin, Promethazine, and Micronutrients for Rapid Clinical Recovery in Mild to Moderate COVID-19 Patients: A Randomized Controlled Clinical Trial
89% improved recovery [p=0.05]. RCT 260 patients in India, 130 treated with aspirin, promethazine, vitamin C, D, B3, zinc, and selenium, showing faster recovery with treatment. There was no hospitalization, ICU admission, or supplemental oxygen requirements in either gr..
May 27
Galmés et al., Nutrients, doi:10.3390/nu14112254 Suboptimal Consumption of Relevant Immune System Micronutrients Is Associated with a Worse Impact of COVID-19 in Spanish Populations
Ecological study in Spain, showing lower intake of vitamin D, A, B9, and zinc in regions with the highest COVID-19 incidence and mortality. Vitamin D intake was associated with lower prevalence, incidence, and a combined incidence+mortali..
May 19
Hellou et al., Journal of Cellular and Molecular Medicine, doi:10.1111/jcmm.17337 Effect of ArtemiC in patients with COVID-19: A Phase II prospective study
77% improved recovery [p=0.04], 92% lower need for oxygen therapy [p=0.01], 13% shorter hospitalization [p=0.92], and 10% improved viral clearance [p=0.77]. RCT 50 hospitalized patients in Israel, 33 treated with curcumin, vitamin C, artemisinin, and frankincense oral spray, showing improved recovery with treatment.
May 18
Yildirim et al., Research Square, doi:10.21203/rs.3.rs-1666161/v1 (Preprint) Mortality Predictors Of Pre-variant SARS-CoV-2 Infected ARDS Patients Receiving Favipiravir and Tocilizumab
Retrospective 60 ICU patients in Turkey treated with tocilizumab and favipiravir, reporting that there was a higher rate of vitamin C treatment in surviving patients (35% vs 10%; p = 0.03), however the results in the table do not match. T..
May 13
Zangeneh et al., Obesity Medicine, doi:10.1016/j.obmed.2022.100420 Survival analysis based on body mass index in patients with Covid-19 admitted to the intensive care unit of Amir Al-Momenin Hospital in Arak – 2021
4% lower mortality [p=0.86]. Retrospective 193 ICU patients in Iran, showing no significant difference with vitamin C treatment.
Apr 20
Pandya et al., Informatics in Medicine Unlocked, doi:10.1016/j.imu.2022.100951 Unravelling Vitamin B12 as a potential inhibitor against SARS-CoV-2: A computational approach
In Silico study showing significant interaction with SARS-CoV-2 targets for multiple vitamins.
Mar 29
Hess et al., Internal and Emergency Medicine, doi:10.1007/s11739-022-02954-6 High-dose intravenous vitamin C decreases rates of mechanical ventilation and cardiac arrest in severe COVID-19
20% lower mortality [p=0.54], 40% lower ventilation [p=0.05], and 27% lower ICU admission [p=0.11]. Retrospective 100 severe condition hospitalized patients in the USA, 25 treated with high dose IV vitamin C, showing lower mechanical ventilation and cardiac arrest, and increased length of survival with treatment. 3g IV vitamin C every ..
Mar 19
Coppock et al., Life, doi:10.3390/life12030453 Pharmacologic Ascorbic Acid as Early Therapy for Hospitalized Patients with COVID-19: A Randomized Clinical Trial
50% better improvement [p=0.16] and 22% higher hospital discharge [p=0.07]. RCT with 66 very late stage (8 days from symptom onset) hospitalized patients, 44 treated with vitamin C and 22 control patients, showing no significant differences with treatment.
Mar 11
Salehi et al., Research Square, doi:10.21203/rs.3.rs-1362678/v1 (Preprint) Risk factors of death in mechanically ventilated COVID-19 patients: a retrospective multi-center study
10% lower mortality [p=0.56]. Retrospective 125 mechanically ventilated ICU patients in Iran, showing no significant difference with vitamin C treatment in unadjusted results.
Feb 28
Shehab et al., Tropical Journal of Pharmaceutical Research, doi:10.4314/tjpr.v21i2.13 Immune-boosting effect of natural remedies and supplements on progress of, and recovery from COVID-19 infection
4% lower severe cases [p=1]. Retrospective survey-based analysis of 349 COVID-19 patients, showing no significant difference with vitamin C prophylaxis in unadjusted analysis. REC/UG/2020/03.
Feb 28
Nimer et al., Bosnian Journal of Basic Medical Sciences, doi:10.17305/bjbms.2021.7009 The impact of vitamin and mineral supplements usage prior to COVID-19 infection on disease severity and hospitalization
25% lower hospitalization [p=0.08] and 17% lower severe cases [p=0.18]. Retrospective survey based analysis of 2,148 COVID-19 recovered patients in Jordan, showing lower risk of severity and hospitalization with vitamin C prophylaxis, without statistical significance.
Feb 26
Hajdrik et al., Foods, doi:10.3390/foods11050694 (In Vitro) In Vitro Determination of Inhibitory Effects of Humic Substances Complexing Zn and Se on SARS-CoV-2 Virus Replication
In Vitro study of a humic substance containing vitamin C, selemium ions, and zinc ions, showing 50% SARS-CoV-2 inhibition at picomolar concentrations.
Feb 24
Kory et al., Journal of Clinical Medicine Research, doi:10.14740/jocmr4658 (Review) “MATH+” Multi-Modal Hospital Treatment Protocol for COVID-19 Infection: Clinical and Scientific Rationale
Review of the data supporting the MATH+ hospital treatment protocol for COVID-19.
Feb 11
Gavrielatou et al., Frontiers in Medicine, doi:10.3389/fmed.2022.814587 Effect of Vitamin C on Clinical Outcomes of Critically Ill Patients With COVID-19: An Observational Study and Subsequent Meta-Analysis
58% lower mortality [p=0.11]. Retrospective 113 consecutive mechanically ventilated COVID+ ICU patients in Greece, 10 receiving high dose IV vitamin C, showing lower mortality with treatment, without statistical significance (p=0.11). The associated meta analysis incl..
Jan 29
Mohajeri et al., Mediterranean Journal of Nutrition and Metabolism, doi:10.3233/MNM-211521 The difference in the dietary inflammatory index, functional food, and antioxidants intake between COVID -19 patients and healthy persons
Retrospective dietary survey analysis of 500 COVID-19 patients and 500 healthy matched controls in Iran, showing dietary inflammatory index associated with increased risk of COVID-19. IR.ARUMS.REC.1400.008.
Jan 29
Mohajeri et al., Mediterranean Journal of Nutrition and Metabolism, doi:10.3233/MNM-211521 The difference in the dietary inflammatory index, functional food, and antioxidants intake between COVID -19 patients and healthy persons
Retrospective dietary survey analysis of 500 COVID-19 patients and 500 healthy matched controls in Iran, showing that COVID-19 patients had lower daily consumption of vitamin C, vitamin D, vitamin E, zinc, and selenium. IR.ARUMS.REC.1400...
Jan 21
Goc et al., European Journal of Microbiology and Immunology, doi:10.1556/1886.2021.00022 (In Vitro) Inhibitory effects of specific combination of natural compounds against SARS-CoV-2 and its Alpha, Beta, Gamma, Delta, Kappa, and Mu variants
In Vitro study testing combinations of plant extracts and micronutrients with several variants of SARS-CoV-2. A combination of vitamin C, N-acetylcysteine, curcumin, quercetin, resveratrol, theaflavin, naringenin, baicalin, and broccoli e..
Jan 15
Yang et al., Am. J. Transl. Res., 14:1 Traditional Chinese medicine together with high-dose vitamin C improves the therapeutic effect of western medicine against COVID-19
15% faster recovery [p=0.15] and 14% faster viral clearance [p=0.25]. Prospective study of 60 patients in China with three arms: SOC, SOC+TCM, and SOC+TCM+high dose vitamin C, showing successively faster recovery with the addition of TCM and the addition of high dose vitamin C. TCM included low dose vitamin..
Jan 13
Tu et al., Infectious Diseases & Immunity, doi:10.1097/ID9.0000000000000037 Risk Factors for Severity and Mortality in Adult Patients Confirmed with COVID-19 in Sierra Leone: A Retrospective Study
83% lower mortality [p<0.0001]. Retrospective 180 hospitalized COVID-19 patients in Sierra Leone, showing lower mortality with vitamin C treatment in unadjusted results.
Dec 28
2021
Baguma et al., Research Square, doi:10.21203/rs.3.rs-1193578/v1 (Preprint) Characteristics of the COVID-19 patients treated at Gulu Regional Referral Hospital, Northern Uganda: A cross-sectional study
48% higher mortality [p=0.54]. Retrospective COVID+ hospitalized patients in Uganda, 385 patients receiving vitamin C treatment, showing higher mortality with treatment, without statistical significance.
Dec 15
2021
Majidi et al., Frontiers in Immunology, doi:10.3389/fimmu.2021.717816 The Effect of Vitamin C on Pathological Parameters and Survival Duration of Critically Ill Coronavirus Disease 2019 Patients: A Randomized Clinical Trial
14% lower mortality [p=0.03]. RCT 100 ICU patients in Iran, 31 treated with vitamin C, showing lower mortality with treatment. IRCT20151226025699N5.
Dec 14
2021
Amssayef et al., Cardiovascular & Hematological Disorders-Drug Targets, doi:10.2174/1871529X21666211214153308 (Ex Vivo) Vitamin C inhibits Angiotensin-Converting Enzyme-2 in Isolated Rat Aortic Ring
Ex Vivo study showing vitamin C inhibiting vascular ACE2.
Nov 25
2021
Ried et al., Cureus, doi:10.7759/cureus.19902 Therapies to Prevent Progression of COVID-19, Including Hydroxychloroquine, Azithromycin, Zinc, and Vitamin D3 With or Without Intravenous Vitamin C: An International, Multicenter, Randomized Trial
31% improved recovery [p=0.008]. RCT 237 patients in Turkey, 162 treated with IV vitamin C in addition to HCQ/AZ/zinc/vitamin D used for all patients, showing significantly faster recovery with the addition of IV vitamin C. 97% of patients were vitamin D deficient, and l..
Nov 14
2021
Beigmohammadi et al., Trials, doi:10.1186/s13063-021-05795-4 The effect of supplementation with vitamins A, B, C, D, and E on disease severity and inflammatory responses in patients with COVID-19: a randomized clinical trial
89% lower mortality [p=0.11], 41% lower hospitalization [p=0.25], and 45% improved recovery [p=0.001]. Small RCT 60 ICU patients in Iran, 30 treated with vitamins A, B, C, D, and E, showing significant improvement in SOFA score and several inflammatory markers at day 7 with treatment. 5,000 IU vitamin A daily, 600,000 IU vitamin D once, 30..
Nov 8
2021
Tehrani et al., Urology Journal, doi:10.22037/uj.v18i.6863 An investigation into the Effects of Intravenous Vitamin C on Pulmonary CT Findings and Clinical Outcomes of Patients with COVID 19 Pneumonia A Randomized Clinical Trial
87% lower mortality [p=0.13] and 18% shorter hospitalization [p=0.23]. RCT 54 late stage patients, 18 treated with IV vitamin C (2g every 6h for 5 days), showing significant relative improvements in oxygen saturation and respiratory rate.
Oct 28
2021
Shousha et al., World Journal of Gastroenterology, doi:10.3748/wjg.v27.i40.6951 Hepatic and gastrointestinal disturbances in Egyptian patients infected with coronavirus disease 2019: A multicentre cohort study
94% lower mortality [p=0.003]. Retrospective 547 hospitalized COVID+ patients in Egypt, showing lower mortality with vitamin C treatment. Treatment was applied according to the official guidelines, indicating that vitamin C was co-administered with HCQ. Actual treatmen..
Oct 25
2021
Leal-Martínez et al., International Journal of Environmental Research and Public Health, doi:10.3390/ijerph19031172 (date from earlier preprint) Effect of a Nutritional Support System to Increase Survival and Reduce Mortality in Patients with COVID-19 in Stage III and Comorbidities: A Blinded Randomized Controlled Clinical Trial
86% lower mortality [p=0.03] and 57% lower ventilation [p=0.31]. 80 patient RCT with 40 patients treated with a comprehensive regimen of nutritional support, showing significantly lower mortality with treatment. Treatment contained cholecalciferol, vitamin C, zinc, spirulina maxima, folic acid, glutami..
Oct 20
2021
Deschasaux-Tanguy et al., European Journal of Public Health, doi:10.1093/eurpub/ckab165.243 Nutritional risk factors for SARS-CoV-2 infection: prospective study from the NutriNet-Santé cohort
Analysis of 7,766 adults in France, showing higher intakes of vitamin C, folates, vitamin K, dietary fibre, and fruit and vegetables associated with a lower seroprevalence of anti-SARS-CoV-2 antibodies.
Sep 27
2021
Simsek et al., Annals of Medical Research, doi:10.5455/annalsmedres.2020.10.1043 Effects of high dose vitamin C administration in Covid-19 patients
44% lower mortality [p=0.19] and 10% lower ICU admission [p=0.66]. Retrospective 139 hospitalized patients in Turkey, 58 treated with high dose vitamin C, showing improved kidney functioning with treatment. Mortality was lower with treatment, but not reaching statistical significance with the small sampl..
Sep 22
2021
Zheng et al., Open Medicine, doi:10.1515/med-2021-0361 No significant benefit of moderate-dose vitamin C on severe COVID-19 cases
157% higher mortality [p=0.33] and 35% worse improvement [p=0.17]. Retrospective 397 severe COVID-19 patients in China, showing worse outcomes with vitamin C treatment, without statistical significance. IV vitamin C 2-4g/day. Subject to confounding by indication and immortal time bias. Exclusion criteria..
Sep 7
2021
Xia et al., Aging, doi:10.18632/aging.203503 High-dose vitamin C ameliorates cardiac injury in COVID-19 pandemic: a retrospective cohort study
Retrospective 113 severe and critical patients in China with cardiac injury, 51 treated with high dose vitamin C, showing treatment associated with improvement of myocardial injury.
Aug 17
2021
Capone et al., Cureus, doi:10.7759/cureus.9809 Characterization of Critically Ill COVID-19 Patients at a Brooklyn Safety-Net Hospital
Retrospective 102 ICU patients in the USA, 73 receiving vitamin C and zinc, showing a negative correlation of treatment with mortality, but not reaching statistical significance (p = 0.31).
Aug 4
2021
Mohseni et al., Nutrition & Food Science, doi:10.1108/NFS-11-2020-0421 Do body mass index (BMI) and history of nutritional supplementation play a role in the severity of COVID-19? A retrospective study
44% more cases [p=0.002]. Retrospective 603 patients in Iran, 34 taking vitamin C supplements, showing increased risk of COVID-19 cases in unadjusted results. IR.SHOUSHTAR.REC.1399.015.
Jul 26
2021
Tan et al., QJM, doi:10.1093/qjmed/hcab184 Efficacy of diammonium glycyrrhizinate combined with vitamin C for treating hospitalized COVID-19 patients: a retrospective, observational stud
25% lower combined mortality/intubation [p=0.74] and 73% lower progression [p=0.002]. PSM retrospective 207 hospitalized patients in China, 46 treated with diammonium glycyrrhizinate and vitamin C, showing lower risk of ARDS with treatment.
Jul 9
2021
Rabail et al., Food Science & Nutrition, doi:10.1002/fsn3.2458 Nutritional and lifestyle changes required for minimizing the recovery period in home quarantined COVID-19 patients of Punjab, Pakistan
Survey of 80 recovered COVID-19 patients in Pakistan, showing faster recovery with vitamin C, vitamin D, and zinc supplementation.
Jul 6
2021
Margolin et al., Journal of Evidence-Based Integrative Medicine, doi:10.1177/2515690X211026193 20-Week Study of Clinical Outcomes of Over-the-Counter COVID-19 Prophylaxis and Treatment
94% fewer cases [p=0.003]. Retrospective 113 outpatients, 53 (patient choice) treated with zinc, quercetin, vitamin C/D/E, l-lysine, and quina, showing lower cases with treatment. Results are subject to selection bias and limited information on the groups is provid..
Jul 4
2021
Özgünay et al., The European Research Journal, doi:10.18621/eurj.938778 The use of vitamin C in the intensive care unit during the COVID-19 pandemic
9% lower mortality [p=0.69] and 1% higher ventilation [p=1]. Retrospective 160 ICU patients, 32 with raised neutrophil/lymphocyte ratio treated with vitamin C, showing no significant differences.
Jun 30
2021
Vishnuram et al., Indian Journal of Basic and Applied Medical Research, doi:10.36848/IJBAMR/2020/29215.55599 Role of high dose oral liposomal vitamin C in reducing mortality in patients with COVID-19
54% lower mortality [p=0.03]. Retrospective 8,634 hospitalized patients in India, showing lower mortality with high-dose vitamin C in unadjusted results. No group details are provided, the text and table appear to show different results, and some numbers do not match.
Jun 8
2021
Li et al., Journal of Pharmacy Practice, doi:10.1177/08971900211015052 Use of Intravenous Vitamin C in Critically Ill Patients With COVID-19 Infection
11% higher mortality [p=1]. PSM retrospective 8 ICU patients treated with vitamin C and 24 matched controls, showing no significant difference. Authors note that "it is possible for the delayed timing of IV vitamin C to have blunted the beneficial effects as th..
Jun 1
2021
May et al., British Journal of Pharmacology, doi:10.1111/bph.15579 (Review) Therapeutic potential of megadose vitamin C to reverse organ dysfunction in sepsis and COVID-19
Review of data supporting the use of megadose vitamin C as a treatment for sepsis and COVID-19.
May 26
2021
Pourhoseingholi et al., Research Square, doi:10.21203/rs.3.rs-365321/v2 (Preprint) Case Characteristics, Clinical Data, And Outcomes of Hospitalized COVID-19 Patients In Qom Province, Iran: A Prospective Cohort Study
13% lower mortality [p=0.38]. Prospective study of 2,468 hospitalized COVID-19 patients in Iran, showing no significant difference with vitamin C treatment. IR.MUQ.REC.1399.013.
May 11
2021
Aldwihi et al., International Journal of Environmental Research and Public Health, doi:10.3390/ijerph18105086 Patients’ Behavior Regarding Dietary or Herbal Supplements before and during COVID-19 in Saudi Arabia
36% lower hospitalization [p=0.006]. Retrospective survey-based analysis of 738 COVID-19 patients in Saudi Arabia, showing lower hospitalization with vitamin C, turmeric, zinc, and nigella sativa, and higher hospitalization with vitamin D. For vitamin D, most patients contin..
May 11
2021
Suna et al., Med. Clin. (Barc.), doi:10.1016/j.medcli.2021.04.010 Effect of high-dose intravenous vitamin C on prognosis in patients with SARS-CoV-2 pneumonia
21% lower mortality [p=0.52] and 2% higher ICU admission [p=1]. Retrospective 323 hospitalized patients, 153 treated with vitamin C, showing no significant differences. Patients in each group were in different time periods, with the vitamin C group first. Time based confounding is possible due to impr..
May 3
2021
Malla et al., bioRxiv, doi:10.1101/2021.05.02.442358 (Preprint) Vitamin C inhibits SARS coronavirus-2 main protease essential for viral replication
In Vitro study showing that vitamin C inhibits SARS-CoV-2 3CLpro. Authors note that the different clinical results may be explained in part by the widely varying dosages used, and they conclude that vitamin C and/or derivatives may become..
Apr 30
2021
Elhadi et al., PLOS ONE, doi:10.1371/journal.pone.0251085 Epidemiology, outcomes, and utilization of intensive care unit resources for critically ill COVID-19 patients in Libya: A prospective multi-center cohort study
12% higher mortality [p=0.15]. Prospective study of 465 COVID-19 ICU patients in Libya showing no significant differences with treatment.
Apr 22
2021
Zhao et al., Frontiers in Pharmacology, doi:10.3389/fphar.2021.638556 High Dose Intravenous Vitamin C for Preventing The Disease Aggravation of Moderate COVID-19 Pneumonia. A Retrospective Propensity Matched Before-After Study
72% lower progression [p=0.03] and 8% slower viral clearance [p=0.79]. PSM retrospective 110 patients, 55 treated with high-dose IV vitamin C, showing lower progression to severe disease with treatment. Patients in each group were in different time periods, time based confounding is likely due to SOC improvi..
Apr 14
2021
Hakamifard et al., Immunopathologia Persa, doi:10.34172/ipp.2021.xx The effect of vitamin E and vitamin C in patients with COVID-19 pneumonia; a randomized controlled clinical trial
46% lower ICU admission [p=0.46] and 1% shorter hospitalization [p=0.82]. RCT with 38 patients treated with vitamin C and vitamin E, and 34 control patients, showing lower ICU admission with treatment, but not statistically significant.
Apr 8
2021
Abdulateef et al., Open Medicine, doi:10.1515/med-2021-0273 COVID-19 severity in relation to sociodemographics and vitamin D use
19% lower hospitalization [p=0.69]. Survey of 428 recovered COVID-19 patients in Iraq, showing fewer hospital visits for patients on prophylactic vitamin C or D. Hospitalization was lower for those on vitamin C, D, or zinc, without statistical significance.
Apr 8
2021
Gadhiya et al., BMJ Open, doi:10.1136/bmjopen-2020-042549 Clinical characteristics of hospitalised patients with COVID-19 and the impact on mortality: a single-network, retrospective cohort study from Pennsylvania state
1% higher mortality [p=0.99]. Retrospective 283 patients in the USA showing higher mortality with all treatments (not statistically significant). Confounding by indication is likely. In the supplementary appendix, authors note that the treatments were usually given fo..
Apr 7
2021
Mulhem et al., BMJ Open, doi:10.1136/bmjopen-2020-042042 3219 hospitalised patients with COVID-19 in Southeast Michigan: a retrospective case cohort study
32% higher mortality [p=0.01]. Retrospective database analysis of 3,219 hospitalized patients in the USA. Very different results in the time period analysis (Table S2), and results significantly different to other studies for the same medications (e.g., heparin OR 3.06..
Apr 2
2021
Al Sulaiman et al., Research Square, doi:10.21203/rs.3.rs-354711/v1 (Preprint) Ascorbic Acid as an Adjunctive Therapy in Critically Ill Patients with COVID-19: A Multicenter Propensity Score Matched Study
15% lower mortality [p=0.27]. Retrospective 158 critically ill patients receiving vitamin C and propensity matched controls, showing mortality OR 0.77 [0.48-1.23], and statistically significantly lower thrombosis, OR 0.42 [0.18-0.94]. 1000mg of vitamin C was given dai..
Mar 30
2021
Holt et al., Thorax, doi:10.1136/thoraxjnl-2021-217487 Risk factors for developing COVID-19: a population-based longitudinal study (COVIDENCE UK)
3% more cases [p=0.86]. Prospective survey-based study with 15,227 people in the UK, showing lower risk of COVID-19 cases with vitamin A, vitamin D, zinc, selenium, probiotics, and inhaled corticosteroids; and higher risk with metformin and vitamin C. Statistica..
Mar 8
2021
Hamidi-Alamdari et al., Clinical and Translational Investigation, doi:10.24875/RIC.21000028 Methylene blue for treatment of hospitalized COVID-19 patients: a randomized, controlled, open-label clinical trial, phase 2
44% lower mortality [p=0.38] and 38% shorter hospitalization [p=0.004]. RCT 80 hospitalized patients with severe COVID-19, 40 treated with methylene blue + vitamin C + N-acetylcysteine, showing lower mortality, shorter hospitalization, and significantly improved SpO2 and respiratory distress with treatment. N..
Mar 2
2021
Hemilä et al., Research Square, doi:10.21203/rs.3.rs-289381/v1 (Preprint) (meta analysis) Vitamin C may increase the recovery rate of outpatient cases of SARS-CoV-2 infection by 70%: reanalysis of the COVID A to Z Randomized Clinical Trial
Reanalysis of Thomas et al. showing that vitamin C increased the recovery rate by 70%, p = 0.025.
Feb 26
2021
Gao et al., Aging, doi:10.18632/aging.202557 The efficiency and safety of high-dose vitamin C in patients with COVID-19: a retrospective cohort study
86% lower mortality [p=0.04]. Retrospective 76 COVID-19 patients, 46 treated with intravenous high-dose vitamin C, showing lower mortality and improved oxygen requirements with treatment. Dosage was 6g intravenous infusion per 12hr on the first day, and 6g once for th..
Feb 15
2021
Mahto et al., American Journal of Blood Research, 11:1 Seroprevalence of IgG against SARS-CoV-2 and its determinants among healthcare workers of a COVID-19 dedicated hospital of India
26% higher IgG positivity [p=0.49]. Retrospective 689 healthcare workers in India, showing no significant difference in IgG positivity with vitamin C prophylaxis.
Feb 12
2021
Thomas et al., JAMA Network Open, doi:10.1001/jamanetworkopen.2021.0369 Effect 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 Trial
18% faster recovery [p=0.15]. Small 214 low-risk outpatient RCT showing non-statistically significant faster recovery with zinc and with vitamin C. NCT04342728. A secondary analysis concludes that vitamin C increases recovery rate by 71% (p = 0.036) . See also .
Feb 9
2021
Hancock et al., SSRN, doi:10.2139/ssrn.3779211 (Preprint) Case Cluster of RT-PCR COVID-19 Positive Patients with an Unexpected Benign Clinical Course With Vitamin D, Melatonin, Vitamin C, and Viscum Album
Case series of 24 COVID-19 patients (12 confirmed PCR+) treated with vitamin D, vitamin C, and melatonin, showing positive outcomes with no patient having worse than a mild case, including 7 high risk patients.
Feb 1
2021
Muhammad et al., SAGE Open Medicine, doi:10.1177/2050312121991246 Deficiency of antioxidants and increased oxidative stress in COVID-19 patients: A cross-sectional comparative study in Jigawa, Northwestern Nigeria
Case control study with 50 symptomatic COVID-19 patients and 21 healthy controls in Nigeria, showing that COVID-19 patients had significantly lower levels of selenium and zinc, and vitamins A, C, and E. Control patients were younger than ..
Feb 1
2021
Zhao et al., Ann. Palliat. Med., doi:10.21037/apm-20-1387 Beneficial aspects of high dose intravenous vitamin C on patients with COVID-19 pneumonia in severe condition: a retrospective case series study
Retrospective case study of 12 severe/critical COVID-19 patients finding that high dose IV vitamin C improved inflammatory response, immune and organ function. There was no control group.
Jan 27
2021
Xing et al., Journal of Pharmaceutical and Biomedical Analysis, doi:10.1016/j.jpba.2021.113927 Vitamin C supplementation is necessary for patients with coronavirus disease: An ultra-high-performance liquid chromatography-tandem mass spectrometry finding
Prospective study with 31 COVID-19 patients and 60 controls reporting on a new method to assess plasma vitamin C concentrations. Vitamin C was deficient (11.4µmol/l vs. 52µmol/l for healthy controls), and returned to a normal range (76µmo..
Jan 18
2021
Hemilä et al., Frontiers in Medicine, doi:10.3389/fmed.2020.559811 (Review) Vitamin C and COVID-19
Review of the use of vitamin C for infections and the potential benefit for COVID-19.
Jan 9
2021
JamaliMoghadamSiahkali et al., Research Square, doi:10.21203/rs.3.rs-139942/v1 (Preprint) Safety and Effectiveness of High-Dose Vitamin C in Patients with COVID-19; A Randomized Controlled open-label Clinical Trial
25% higher ventilation [p=1] and 31% longer hospitalization [p=0.03]. Small late stage RCT for the addition of vitamin C to HCQ and lopinavir/ritonavir, with 30 treatment and 30 control patients, finding a significant reduction in temperature and a significant improvement in oxygenation after 3 days in the ..
Dec 23
2020
Su et al., BioScience Trends, doi:10.5582/bst.2020.03340 Efficacy of early hydroxychloroquine treatment in preventing COVID-19 pneumonia aggravation, the experience from Shanghai, China
135% higher progression [p=0.18] and 34% slower improvement [p=0.04]. Retrospective 616 patients in China showing increased risk of disease progression for vitamin C treatment within five days.
Dec 16
2020
Jang et al., Heart & Lung, doi:10.1016/j.hrtlng.2020.10.010 Clinical course of COVID-19 patients treated with ECMO: A multicenter study in Daegu, South Korea
51% improved recovery [p=0.15]. Retrospective 19 COVID-19 ECMO patients in South Korea, showing a higher rate of weaning from ECMO with vitamin C treatment, without statistical significance. Authors perform multivariate analysis but do not provide full results, only rep..
Dec 15
2020
Darban et al., Journal of Cellular & Molecular Anesthesia, doi:10.22037/jcma.v6i2.32182 Efficacy of High Dose Vitamin C, Melatonin and Zinc in Iranian Patients with Acute Respiratory Syndrome due to Coronavirus Infection: A Pilot Randomized Trial
33% lower progression [p=1] and 6% shorter ICU admission [p=0.3]. Small RCT in Iran with 20 ICU patients, 10 treated with high-dose vitamin C, melatonin, and zinc, not showing significant differences. IRCT20151228025732N52.
Dec 10
2020
Rosenthal et al., JAMA Network Open, doi:10.1001/jamanetworkopen.2020.29058 Risk Factors Associated With In-Hospital Mortality in a US National Sample of Patients With COVID-19
11% lower mortality [p=0.005]. Retrospective database analysis of 64,781 hospitalized patients in the USA, showing lower mortality with vitamin C or vitamin D (authors do not distinguish between the two), and higher mortality with zinc and HCQ, statistically significan..
Dec 7
2020
Holford et al., Nutrients, doi:10.3390/nu12123760 (Review) Vitamin C—An Adjunctive Therapy for Respiratory Infection, Sepsis and COVID-19
Review of vitamin C use for respiratory infections including COVID-19 and the mechanisms of action. Authors note that evidence to date indicates oral vitamin C (2–8 g/day) may reduce the incidence and duration of respiratory infections, a..
Nov 30
2020
Kumari et al., Cureus 12(11): e11779, doi:10.7759/cureus.11779 The Role of Vitamin C as Adjuvant Therapy in COVID-19
36% lower mortality [p=0.45], 20% lower ventilation [p=0.67], 26% faster recovery [p=0.0001], and 24% shorter hospitalization [p=0.0001]. RCT 150 hospitalized patients in Pakistan showing 26% faster recovery, p < 0.0001. 36% lower mortality, not statistically significant due to the small number of events. Dosage was 50 mg/kg/day of intravenous vitamin C.
Nov 30
2020
Louca et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000250 (date from earlier preprint) Modest effects of dietary supplements during the COVID-19 pandemic: insights from 445 850 users of the COVID-19 Symptom Study app
no change in cases [p=1]. Survey analysis of dietary supplements showing no significant difference in PCR+ cases with vitamin C usage in the UK, however significant reductions were found in the US and Sweden. These results are for PCR+ cases only, they do not refl..
Nov 3
2020
Behera et al., PLoS ONE, doi:10.1371/journal.pone.0247163 (date from earlier preprint) Role of ivermectin in the prevention of SARS-CoV-2 infection among healthcare workers in India: A matched case-control study
18% fewer cases [p=0.58]. Retrospective matched case-control prophylaxis study for HCQ, ivermectin, and vitamin C with 372 healthcare workers, showing lower COVID-19 incidence for all treatments, with statistical significance reached for ivermectin. HCQ OR 0.56, p..
Oct 1
2020
Patel et al., Chest Infections, doi:10.1016/j.chest.2020.08.322 The significance of oral ascorbic acid in patients with COVID-19
29% lower mortality [p=0.18]. Retrospective 176 hospitalized patients, 96 treated with oral vitamin C (from 500mg to 1500mg daily), showing lower mortality with treatment.
Sep 20
2020
Yüksel et al., Intensive Care Medicine Experimental, 9:S1, 001458, doi:10.1186/s40635-021-00413-8 (Preprint) Effects of high dose vitamin c on patient outcomes in ARDS patients admitted to intensive care with COVID-19; multi-center retrospective study
19% lower mortality [p=0.04]. PSM retrospective 86 ICU patients on mechanical ventilation in Turkey, showing lower mortality with high dose vitamin C treatment (≥200mg/kg for 4 days).
Sep 8
2020
Arvinte et al., Med. Drug Discov, doi:10.1016/j.medidd.2020.100064 Serum Levels of Vitamin C and Vitamin D in a Cohort of Critically Ill COVID-19 Patients of a North American Community Hospital Intensive Care Unit in May 2020: A Pilot Study
Pilot study with 21 ICU patients finding low serum levels of vitamin C and vitamin D in most patients. Older age and low vitamin C level appeared to be co-dependent risk factors for mortality.
Sep 8
2020
Galmés et al., Nutrients, doi:10.3390/nu12092738 Current State of Evidence: Influence of Nutritional and Nutrigenetic Factors on Immunity in the COVID-19 Pandemic Framework
Ecological study of European countries analyzing 10 vitamins and minerals endorsed by the European Food Safety Authority as having sufficient evidence for a causal relationship between intake and optimal immune system function: vitamins D..
Aug 26
2020
Chiscano-Camón et al., Critical Care, doi:10.1186/s13054-020-03249-y Vitamin C levels in patients with SARS-CoV-2-associated acute respiratory distress syndrome
Small study of 18 COVID-19 ARDS patients showing that vitamin C levels were very low - 17 patients had undetectable levels and one had a low level (2.4 mg/L).
Aug 10
2020
Zhang et al., Annals of Intensive Care, doi:10.1186/s13613-020-00792-3 Pilot Trial of High-dose vitamin C in critically ill COVID-19 patients (preprint 8/10/2020)
50% lower mortality [p=0.2]. Small RCT for high dose vitamin C for ICU patients showing reduced (but not statistically significant) mortality. Dosage was 12g of vitamin C/50ml every 12 hours for 7 days at a rate of 12ml/hour.
Aug 1
2020
Hiedra et al., Expert Review of Anti-infective Therapy, doi:10.1080/14787210.2020.1794819 The use of IV vitamin C for patients with COVID-19: a case series
Case study of 17 patients receiving IV vitamin C for COVID-19, finding a significant decrease in inflammatory markers, including ferritin and D-dimer, and a trend to decreasing FiO2 requirements, after vitamin C administration. There was ..
Jul 25
2020
Feyaerts et al., Nutrition, doi:10.1016/j.nut.2020.110948 (Review) Vitamin C as prophylaxis and adjunctive medical treatment for COVID-19?
Review concluding that there is clear evidence that vitamin C in high doses can reduce interleukin-6 and endothelin-1 mediators. Authors suggest a relatively low dose as prophylaxis, and in cases of severe COVID-19, an (intravenous) high-..
Jul 20
2020
Krishnan et al., J Clin Anesth., doi:10.1016/j.jclinane.2020.110005 Clinical comorbidities, characteristics, and outcomes of mechanically ventilated patients in the State of Michigan with SARS-CoV-2 pneumonia
31% lower mortality [p=0.04]. Retrospective 152 mechanically ventilated patients in the USA showing unadjusted lower mortality with vitamin C, vitamin D, HCQ, and zinc treatment, statistically significant only for vitamin C.
Jun 19
2020
Biancatelli et al., Frontiers in Immunology, doi:10.3389/fimmu.2020.01451 (Review) Quercetin and Vitamin C: An Experimental, Synergistic Therapy for the Prevention and Treatment of SARS-CoV-2 Related Disease (COVID-19)
Review of the evidence for the use of vitamin C and quercetin both for prophylaxis in high-risk populations and for the treatment of COVID-19 patients.
May 27
2020
Kumar et al., VirusDisease, doi:10.1007/s13337-020-00643-6 (date from earlier preprint) In silico virtual screening-based study of nutraceuticals predicts the therapeutic potentials of folic acid and its derivatives against COVID-19
In Silico analysis finding that magnesium ascorbate, a form of Vitamin C, was found to be the top compound among 106 nutraceuticals for binding to Mpro of SARS-CoV-2.
Please send us corrections, updates, or comments. Vaccines and treatments are complementary. All practical, effective, and safe means should be used based on risk/benefit analysis. No treatment, vaccine, or intervention is 100% available and effective for all current and future variants. We do not provide medical advice. Before taking any medication, consult a qualified physician who can provide personalized advice and details of risks and benefits based on your medical history and situation. FLCCC and WCH provide treatment protocols.
  or use drag and drop   
Thanks for your feedback! Please search before submitting papers and note that studies are listed under the date they were first available, which may be the date of an earlier preprint.
Submit