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Introduction
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Heterogeneity
Discussion
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Study Notes 
Appendix 1. Methods and Study..
Supplementary Data
References

All studies
Mortality
Ventilation
ICU admission
Hospitalization
Progression
Recovery
COVID-19 cases
Viral clearance
High dose IV
Peer reviewed
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All RCTs
RCT mortality

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Aspirin
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Vitamin C for COVID-19: real-time meta analysis of 30 studies
Covid Analysis, January 18, 2022, DRAFT
https://c19vitaminc.com/meta.html
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ All studies 11% 30 32,026 Improvement, Studies, Patients Relative Risk With exclusions 20% 18 2,220 Mortality 15% 20 15,169 Ventilation 1% 3 370 ICU admission 6% 4 554 Hospitalization 12% 7 931 Recovery 26% 3 485 Cases -8% 4 15,830 Viral clearance -8% 1 110 RCTs 33% 9 817 RCT mortality 41% 6 488 Peer-reviewed 12% 26 31,115 High dose IV 23% 13 1,493 Prophylaxis -6% 5 16,257 Early 43% 3 445 Late 16% 22 15,324 Vitamin C for COVID-19 c19vitaminc.com Jan 18, 2022 Favors vitamin C Favors control
Statistically significant improvements are seen for progression and recovery. 10 studies from 6 different countries show statistically significant improvements in isolation (6 for the most serious outcome).
Meta analysis using the most serious outcome reported shows 11% [0‑21%] improvement. Results are better for Randomized Controlled Trials, similar after exclusions, and similar for peer-reviewed studies. Clinical outcomes suggest benefit while viral and case outcomes do not, consistent with an intervention that aids recovery but is not antiviral. Early treatment is more effective than late treatment. High dose IV treatment is more effective.
In exclusion sensitivity analysis, statistical significance is lost after excluding only one of 30 studies in pooled analysis.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ All studies 11% 30 32,026 Improvement, Studies, Patients Relative Risk With exclusions 20% 18 2,220 Mortality 15% 20 15,169 Ventilation 1% 3 370 ICU admission 6% 4 554 Hospitalization 12% 7 931 Recovery 26% 3 485 Cases -8% 4 15,830 Viral clearance -8% 1 110 RCTs 33% 9 817 RCT mortality 41% 6 488 Peer-reviewed 12% 26 31,115 High dose IV 23% 13 1,493 Prophylaxis -6% 5 16,257 Early 43% 3 445 Late 16% 22 15,324 Vitamin C for COVID-19 c19vitaminc.com Jan 18, 2022 Favors vitamin C Favors control
The treatment regimen varies widely across studies and may be high-dose IV vitamin C.
While many treatments have some level of efficacy, they do not replace vaccines and other measures to avoid infection. Only 3% of vitamin C studies show zero events in the treatment arm.
Multiple treatments are typically used in combination, and other treatments are significantly more effective.
Elimination of COVID-19 is a race against viral evolution. No treatment, vaccine, or intervention is 100% available and effective for all variants. All practical, effective, and safe means should be used, including treatments, as supported by Pfizer [Pfizer]. Denying the efficacy of treatments increases mortality, morbidity, collateral damage, and endemic risk.
All data to reproduce this paper and sources are in the appendix.
Studies Early treatment Late treatment Prophylaxis PatientsAuthors
All studies 3043% [-23‑73%]16% [0‑30%]-6% [-31‑14%] 32,026 339
With exclusions 1830% [10‑46%]23% [11‑33%]0% [-3‑3%] 2,220 226
Peer-reviewed 2643% [-23‑73%]19% [-1‑36%]-6% [-31‑14%] 31,115 281
Randomized Controlled TrialsRCTs 930% [10‑46%]43% [11‑63%] 817 101
Percentage improvement with vitamin C treatment
A
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Thomas (RCT) -204% 3.04 [0.13-72.9] death 1/48 0/50 Improvement, RR [CI] Treatment Control Zhao (PSM) 72% 0.28 [0.08-0.93] progression 4/55 12/55 Ried (RCT) 31% 0.69 [0.54-0.89] no recov. 69/162 46/75 Tau​2 = 0.21, I​2 = 43.0%, p = 0.15 Early treatment 43% 0.57 [0.27-1.23] 74/265 58/180 43% improvement Krishnan 31% 0.69 [0.47-0.92] death 40/79 52/73 Improvement, RR [CI] Treatment Control Zhang (RCT) 50% 0.50 [0.20-1.50] death 6/27 11/29 Yüksel (PSM) 19% 0.81 [0.66-0.99] death 31/42 40/44 Patel 29% 0.71 [0.43-1.14] death 22/96 26/80 Kumari (RCT) 36% 0.64 [0.26-1.55] death 7/75 11/75 Darban (RCT) 33% 0.67 [0.14-3.17] progression 2/10 3/10 CT​1 JamaliMog.. (RCT) 0% 1.00 [0.22-4.56] death 3/30 3/30 Gao 86% 0.14 [0.03-0.72] death 1/46 5/30 Hamidi-Ala.. (RCT) 44% 0.56 [0.20-1.51] death 5/40 9/40 CT​1 Al Sulaiman (PSM) 15% 0.85 [0.61-1.12] death 46/142 59/142 Mulhem -32% 1.32 [1.07-1.62] death 157/794 359/2,425 Gadhiya -1% 1.01 [0.48-1.91] death 19/55 36/226 Hakamifard (RCT) 46% 0.54 [0.14-2.08] ICU 3/38 5/34 CT​1 Suna 21% 0.79 [0.44-1.41] death 17/153 24/170 Li (PSM) -11% 1.11 [0.79-1.54] death 7/8 19/24 Vishnuram 54% 0.46 [0.24-0.86] death 164/8,634 10/241 Özgünay 9% 0.91 [0.63-1.30] death 17/32 75/128 Tan 25% 0.75 [0.10-2.98] int./death 1/46 14/115 CT​1 Zheng (PSM) -157% 2.57 [0.39-16.8] death 12/70 7/327 Simsek 44% 0.56 [0.23-1.35] death 6/58 15/81 Tehrani (RCT) 87% 0.13 [0.01-2.25] death 0/18 4/26 Baguma -48% 1.48 [0.41-4.70] death 385 (n) 96 (n) Tau​2 = 0.07, I​2 = 55.7%, p = 0.044 Late treatment 16% 0.84 [0.70-1.00] 566/10,878 787/4,446 16% improvement Behera 18% 0.82 [0.45-1.57] cases case control Improvement, RR [CI] Treatment Control Louca 0% 1.00 [0.97-1.04] cases Holt -3% 1.03 [0.77-1.39] cases 49/1,580 397/13,647 Abdulateef 19% 0.81 [0.37-1.78] hosp. 8/132 22/295 Mohseni -44% 1.44 [1.22-1.71] cases 34/43 307/560 Tau​2 = 0.04, I​2 = 78.3%, p = 0.59 Prophylaxis -6% 1.06 [0.86-1.31] 91/1,755 726/14,502 -6% improvement All studies 11% 0.89 [0.79-1.00] 731/12,898 1,571/19,128 11% improvement 30 vitamin C COVID-19 studies c19vitaminc.com Jan 18, 2022 Tau​2 = 0.04, I​2 = 64.9%, p = 0.049 Effect extraction pre-specified, see appendix 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 1. A. Random effects meta-analysis. This plot shows pooled effects, discussion can be found in the heterogeneity section, and results for specific outcomes can be found in the individual outcome analyses. Effect extraction is pre-specified, using the most serious outcome reported. For details of effect extraction see the appendix. B. Scatter plot showing the distribution of effects reported in studies. C. History of all reported effects (chronological within treatment stages).
Introduction
We analyze all significant studies concerning the use of vitamin C for COVID-19. Search methods, inclusion criteria, effect extraction criteria (more serious outcomes have priority), all individual study data, PRISMA answers, and statistical methods are detailed in Appendix 1. We present random effects meta-analysis results for all studies, for studies within each treatment stage, for individual outcomes, for peer-reviewed studies, for Randomized Controlled Trials (RCTs), and after exclusions.
Figure 2 shows stages of possible treatment for COVID-19. Prophylaxis refers to regularly taking medication before becoming sick, in order to prevent or minimize infection. Early Treatment refers to treatment immediately or soon after symptoms appear, while Late Treatment refers to more delayed treatment.
Figure 2. Treatment stages.
Results
Figure 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13 show forest plots for a random effects meta-analysis of all studies with pooled effects, mortality results, ventilation, ICU admission, hospitalization, progression, recovery, cases, viral clearance, high dose IV studies, and peer reviewed studies. Table 1 summarizes the results by treatment stage.
Treatment timeNumber of studies reporting positive effects Total number of studiesPercentage of studies reporting positive effects Random effects meta-analysis results
Early treatment 2 3 66.7% 43% improvement
RR 0.57 [0.27‑1.23]
p = 0.15
Late treatment 16 22 72.7% 16% improvement
RR 0.84 [0.70‑1.00]
p = 0.044
Prophylaxis 2 5 40.0% -6% improvement
RR 1.06 [0.86‑1.31]
p = 0.59
All studies 20 30 66.7% 11% improvement
RR 0.89 [0.79‑1.00]
p = 0.049
Table 1. Results by treatment stage.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Thomas (RCT) -204% 3.04 [0.13-72.9] death 1/48 0/50 Improvement, RR [CI] Treatment Control Zhao (PSM) 72% 0.28 [0.08-0.93] progression 4/55 12/55 Ried (RCT) 31% 0.69 [0.54-0.89] no recov. 69/162 46/75 Tau​2 = 0.21, I​2 = 43.0%, p = 0.15 Early treatment 43% 0.57 [0.27-1.23] 74/265 58/180 43% improvement Krishnan 31% 0.69 [0.47-0.92] death 40/79 52/73 Improvement, RR [CI] Treatment Control Zhang (RCT) 50% 0.50 [0.20-1.50] death 6/27 11/29 Yüksel (PSM) 19% 0.81 [0.66-0.99] death 31/42 40/44 Patel 29% 0.71 [0.43-1.14] death 22/96 26/80 Kumari (RCT) 36% 0.64 [0.26-1.55] death 7/75 11/75 Darban (RCT) 33% 0.67 [0.14-3.17] progression 2/10 3/10 CT​1 JamaliMog.. (RCT) 0% 1.00 [0.22-4.56] death 3/30 3/30 Gao 86% 0.14 [0.03-0.72] death 1/46 5/30 Hamidi-Ala.. (RCT) 44% 0.56 [0.20-1.51] death 5/40 9/40 CT​1 Al Sulaiman (PSM) 15% 0.85 [0.61-1.12] death 46/142 59/142 Mulhem -32% 1.32 [1.07-1.62] death 157/794 359/2,425 Gadhiya -1% 1.01 [0.48-1.91] death 19/55 36/226 Hakamifard (RCT) 46% 0.54 [0.14-2.08] ICU 3/38 5/34 CT​1 Suna 21% 0.79 [0.44-1.41] death 17/153 24/170 Li (PSM) -11% 1.11 [0.79-1.54] death 7/8 19/24 Vishnuram 54% 0.46 [0.24-0.86] death 164/8,634 10/241 Özgünay 9% 0.91 [0.63-1.30] death 17/32 75/128 Tan 25% 0.75 [0.10-2.98] int./death 1/46 14/115 CT​1 Zheng (PSM) -157% 2.57 [0.39-16.8] death 12/70 7/327 Simsek 44% 0.56 [0.23-1.35] death 6/58 15/81 Tehrani (RCT) 87% 0.13 [0.01-2.25] death 0/18 4/26 Baguma -48% 1.48 [0.41-4.70] death 385 (n) 96 (n) Tau​2 = 0.07, I​2 = 55.7%, p = 0.044 Late treatment 16% 0.84 [0.70-1.00] 566/10,878 787/4,446 16% improvement Behera 18% 0.82 [0.45-1.57] cases case control Improvement, RR [CI] Treatment Control Louca 0% 1.00 [0.97-1.04] cases Holt -3% 1.03 [0.77-1.39] cases 49/1,580 397/13,647 Abdulateef 19% 0.81 [0.37-1.78] hosp. 8/132 22/295 Mohseni -44% 1.44 [1.22-1.71] cases 34/43 307/560 Tau​2 = 0.04, I​2 = 78.3%, p = 0.59 Prophylaxis -6% 1.06 [0.86-1.31] 91/1,755 726/14,502 -6% improvement All studies 11% 0.89 [0.79-1.00] 731/12,898 1,571/19,128 11% improvement 30 vitamin C COVID-19 studies c19vitaminc.com Jan 18, 2022 Tau​2 = 0.04, I​2 = 64.9%, p = 0.049 Effect extraction pre-specified, see appendix 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 3. Random effects meta-analysis for all studies with pooled effects. This plot shows pooled effects, discussion can be found in the heterogeneity section, and results for specific outcomes can be found in the individual outcome analyses. Effect extraction is pre-specified, using the most serious outcome reported. For details of effect extraction see the appendix.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Thomas (RCT) -204% 3.04 [0.13-72.9] 1/48 0/50 Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p = 0.5 Early treatment -204% 3.04 [0.13-72.9] 1/48 0/50 -204% improvement Krishnan 31% 0.69 [0.47-0.92] 40/79 52/73 Improvement, RR [CI] Treatment Control Zhang (RCT) 50% 0.50 [0.20-1.50] 6/27 11/29 Yüksel (PSM) 19% 0.81 [0.66-0.99] 31/42 40/44 Patel 29% 0.71 [0.43-1.14] 22/96 26/80 Kumari (RCT) 36% 0.64 [0.26-1.55] 7/75 11/75 JamaliMog.. (RCT) 0% 1.00 [0.22-4.56] 3/30 3/30 Gao 86% 0.14 [0.03-0.72] 1/46 5/30 Hamidi-Ala.. (RCT) 44% 0.56 [0.20-1.51] 5/40 9/40 CT​1 Al Sulaiman (PSM) 15% 0.85 [0.61-1.12] 46/142 59/142 Mulhem -32% 1.32 [1.07-1.62] 157/794 359/2,425 Gadhiya -1% 1.01 [0.48-1.91] 19/55 36/226 Suna 21% 0.79 [0.44-1.41] 17/153 24/170 Li (PSM) -11% 1.11 [0.79-1.54] 7/8 19/24 Vishnuram 54% 0.46 [0.24-0.86] 164/8,634 10/241 Özgünay 9% 0.91 [0.63-1.30] 17/32 75/128 Zheng (PSM) -157% 2.57 [0.39-16.8] 12/70 7/327 Simsek 44% 0.56 [0.23-1.35] 6/58 15/81 Tehrani (RCT) 87% 0.13 [0.01-2.25] 0/18 4/26 Baguma -48% 1.48 [0.41-4.70] 385 (n) 96 (n) Tau​2 = 0.07, I​2 = 61.4%, p = 0.065 Late treatment 16% 0.84 [0.70-1.01] 560/10,784 765/4,287 16% improvement All studies 15% 0.85 [0.71-1.01] 561/10,832 765/4,337 15% improvement 20 vitamin C COVID-19 mortality results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.07, I​2 = 59.7%, p = 0.071 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 4. Random effects meta-analysis for mortality results.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Kumari (RCT) 20% 0.80 [0.40-1.59] 12/75 15/75 Improvement, RR [CI] Treatment Control JamaliMog.. (RCT) -25% 1.25 [0.37-4.21] 5/30 4/30 Özgünay -1% 1.01 [0.79-1.29] 23/32 91/128 Tau​2 = 0.00, I​2 = 0.0%, p = 0.96 Late treatment 1% 0.99 [0.79-1.24] 40/137 110/233 1% improvement All studies 1% 0.99 [0.79-1.24] 40/137 110/233 1% improvement 3 vitamin C COVID-19 mechanical ventilation results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.00, I​2 = 0.0%, p = 0.96 Favors vitamin C Favors control
Figure 5. Random effects meta-analysis for ventilation.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Darban (RCT) 6% 0.94 [0.84-1.06] 10 (n) 10 (n) CT​1 Improvement, RR [CI] Treatment Control Hakamifard (RCT) 46% 0.54 [0.14-2.08] 3/38 5/34 CT​1 Suna -2% 1.02 [0.46-2.24] 11/153 12/170 Simsek 10% 0.90 [0.55-1.46] 18/58 28/81 Tau​2 = 0.00, I​2 = 0.0%, p = 0.24 Late treatment 6% 0.94 [0.84-1.05] 32/259 45/295 6% improvement All studies 6% 0.94 [0.84-1.05] 32/259 45/295 6% improvement 4 vitamin C COVID-19 ICU results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.00, I​2 = 0.0%, p = 0.24 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 6. Random effects meta-analysis for ICU admission.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Thomas (RCT) 31% 0.69 [0.12-3.98] hosp. 2/48 3/50 Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p = 0.7 Early treatment 31% 0.69 [0.12-3.98] 2/48 3/50 31% improvement Kumari (RCT) 24% 0.76 [0.66-0.87] hosp. time 75 (n) 75 (n) Improvement, RR [CI] Treatment Control JamaliMog.. (RCT) -31% 1.31 [1.03-1.66] hosp. time 30 (n) 30 (n) Hamidi-Ala.. (RCT) 38% 0.62 [0.45-0.86] hosp. time 40 (n) 40 (n) CT​1 Hakamifard (RCT) 1% 0.99 [0.91-1.07] hosp. time 38 (n) 34 (n) CT​1 Tehrani (RCT) 18% 0.82 [0.60-1.13] hosp. time 18 (n) 26 (n) Tau​2 = 0.04, I​2 = 84.0%, p = 0.24 Late treatment 12% 0.88 [0.72-1.09] 0/201 0/205 12% improvement Abdulateef 19% 0.81 [0.37-1.78] hosp. 8/132 22/295 Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p = 0.62 Prophylaxis 19% 0.81 [0.37-1.78] 8/132 22/295 19% improvement All studies 12% 0.88 [0.73-1.06] 10/381 25/550 12% improvement 7 vitamin C COVID-19 hospitalization results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.04, I​2 = 76.2%, p = 0.19 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 7. Random effects meta-analysis for hospitalization.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Zhao (PSM) 72% 0.28 [0.08-0.93] 4/55 12/55 Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p = 0.019 Early treatment 72% 0.28 [0.08-0.93] 4/55 12/55 72% improvement Darban (RCT) 33% 0.67 [0.14-3.17] 2/10 3/10 CT​1 Improvement, RR [CI] Treatment Control Tan 73% 0.27 [0.09-0.61] 7/46 41/115 CT​1 Tau​2 = 0.03, I​2 = 7.9%, p = 0.0021 Late treatment 68% 0.32 [0.16-0.66] 9/56 44/125 68% improvement All studies 70% 0.30 [0.17-0.53] 13/111 56/180 70% improvement 3 vitamin C COVID-19 progression results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.00, I​2 = 0.0%, p < 0.0001 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 8. Random effects meta-analysis for progression.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Thomas (RCT) 18% 0.82 [0.63-1.07] recov. time 48 (n) 50 (n) Improvement, RR [CI] Treatment Control Ried (RCT) 31% 0.69 [0.54-0.89] no recov. 69/162 46/75 Tau​2 = 0.00, I​2 = 0.0%, p = 0.0024 Early treatment 25% 0.75 [0.63-0.90] 69/210 46/125 25% improvement Kumari (RCT) 26% 0.74 [0.64-0.86] recov. time 75 (n) 75 (n) Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p < 0.0001 Late treatment 26% 0.74 [0.64-0.86] 0/75 0/75 26% improvement All studies 26% 0.74 [0.66-0.84] 69/285 46/200 26% improvement 3 vitamin C COVID-19 recovery results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.00, I​2 = 0.0%, p < 0.0001 Favors vitamin C Favors control
Figure 9. Random effects meta-analysis for recovery.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Behera 18% 0.82 [0.45-1.57] cases case control Improvement, RR [CI] Treatment Control Louca 0% 1.00 [0.97-1.04] cases Holt -3% 1.03 [0.77-1.39] cases 49/1,580 397/13,647 Mohseni -44% 1.44 [1.22-1.71] cases 34/43 307/560 Tau​2 = 0.04, I​2 = 83.4%, p = 0.52 Prophylaxis -8% 1.08 [0.86-1.35] 83/1,623 704/14,207 -8% improvement All studies -8% 1.08 [0.86-1.35] 83/1,623 704/14,207 -8% improvement 4 vitamin C COVID-19 case results c19vitaminc.com Jan 18, 2022 Tau​2 = 0.04, I​2 = 83.4%, p = 0.52 Favors vitamin C Favors control
Figure 10. Random effects meta-analysis for cases.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Zhao (PSM) -8% 1.08 [0.64-1.80] viral time 55 (n) 55 (n) Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p = 0.79 Early treatment -8% 1.08 [0.64-1.80] 0/55 0/55 -8% improvement All studies -8% 1.08 [0.64-1.80] 0/55 0/55 -8% improvement 1 vitamin C COVID-19 viral clearance result c19vitaminc.com Jan 18, 2022 Tau​2 = 0.00, I​2 = 0.0%, p = 0.79 Favors vitamin C Favors control
Figure 11. Random effects meta-analysis for viral clearance.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Zhao (PSM) 72% 0.28 [0.08-0.93] progression 4/55 12/55 Improvement, RR [CI] Treatment Control Ried (RCT) 31% 0.69 [0.54-0.89] no recov. 69/162 46/75 Tau​2 = 0.26, I​2 = 62.0%, p = 0.12 Early treatment 49% 0.51 [0.22-1.19] 73/217 58/130 49% improvement Zhang (RCT) 50% 0.50 [0.20-1.50] death 6/27 11/29 Improvement, RR [CI] Treatment Control Yüksel (PSM) 19% 0.81 [0.66-0.99] death 31/42 40/44 Kumari (RCT) 36% 0.64 [0.26-1.55] death 7/75 11/75 Darban (RCT) 33% 0.67 [0.14-3.17] progression 2/10 3/10 CT​1 JamaliMog.. (RCT) 0% 1.00 [0.22-4.56] death 3/30 3/30 Gao 86% 0.14 [0.03-0.72] death 1/46 5/30 Suna 21% 0.79 [0.44-1.41] death 17/153 24/170 Li (PSM) -11% 1.11 [0.79-1.54] death 7/8 19/24 Özgünay 9% 0.91 [0.63-1.30] death 17/32 75/128 Simsek 44% 0.56 [0.23-1.35] death 6/58 15/81 Tehrani (RCT) 87% 0.13 [0.01-2.25] death 0/18 4/26 Tau​2 = 0.00, I​2 = 1.6%, p = 0.017 Late treatment 16% 0.84 [0.72-0.97] 97/499 210/647 16% improvement All studies 23% 0.77 [0.65-0.91] 170/716 268/777 23% improvement 13 high dose IV studies c19vitaminc.com Jan 18, 2022 Tau​2 = 0.02, I​2 = 22.1%, p = 0.0025 Effect extraction pre-specified, see appendix 1 CT: study uses combined treatment Favors vitamin C Favors control
Figure 12. Random effects meta-analysis for high dose IV studies. Effect extraction is pre-specified, using the most serious outcome reported, see the appendix for details.
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Thomas (RCT) -204% 3.04 [0.13-72.9] death 1/48 0/50 Improvement, RR [CI] Treatment Control Zhao (PSM) 72% 0.28 [0.08-0.93] progression 4/55 12/55 Ried (RCT) 31% 0.69 [0.54-0.89] no recov. 69/162 46/75 Tau​2 = 0.21, I​2 = 43.0%, p = 0.15 Early treatment 43% 0.57 [0.27-1.23] 74/265 58/180 43% improvement Krishnan 31% 0.69 [0.47-0.92] death 40/79 52/73 Improvement, RR [CI] Treatment Control Zhang (RCT) 50% 0.50 [0.20-1.50] death 6/27 11/29 Patel 29% 0.71 [0.43-1.14] death 22/96 26/80 Kumari (RCT) 36% 0.64 [0.26-1.55] death 7/75 11/75 Darban (RCT) 33% 0.67 [0.14-3.17] progression 2/10 3/10 CT​1 Gao 86% 0.14 [0.03-0.72] death 1/46 5/30 Hamidi-Ala.. (RCT) 44% 0.56 [0.20-1.51] death 5/40 9/40 CT​1 Mulhem -32% 1.32 [1.07-1.62] death 157/794 359/2,425 Gadhiya -1% 1.01 [0.48-1.91] death 19/55 36/226 Hakamifard (RCT) 46% 0.54 [0.14-2.08] ICU 3/38 5/34 CT​1 Suna 21% 0.79 [0.44-1.41] death 17/153 24/170 Li (PSM) -11% 1.11 [0.79-1.54] death 7/8 19/24 Vishnuram 54% 0.46 [0.24-0.86] death 164/8,634 10/241 Özgünay 9% 0.91 [0.63-1.30] death 17/32 75/128 Tan