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42 vitamin C COVID-19 controlled studies, 12 RCTs
43% improvement
for early treatment, RR
0.57
[0.27-1.23]
https://c19vitaminc.com/meta.html
0
0.5
1
1.5+
All studies
18%
42
39,120
Improvement, Studies, Patients
Relative Risk
Mortality
25%
27
19,087
Ventilation
18%
4
470
ICU admission
15%
5
654
Hospitalization
14%
8
3,079
Recovery
23%
5
571
Cases
-8%
4
15,830
Viral clearance
10%
2
130
RCTs
20%
12
1,003
RCT mortality
17%
7
588
Peer-reviewed
20%
36
35,616
High dose IV
21%
16
1,726
Symptomatic
24%
38
23,290
Prophylaxis
-3%
8
19,347
Early
43%
3
445
Late
25%
31
19,328
Vitamin C for COVID-19
c19vitaminc.com May 2022
Favors vitamin C
Favors control
after exclusions
• Statistically significant improvements are seen for
mortality ,
ICU admission ,
progression , and
recovery . 14 studies from 14 independent teams in 7 different countries show statistically significant
improvements in isolation (7 for the most serious outcome).
0
0.5
1
1.5+
All studies
18%
42
39,120
Improvement, Studies, Patients
Relative Risk
Mortality
25%
27
19,087
Ventilation
18%
4
470
ICU admission
15%
5
654
Hospitalization
14%
8
3,079
Recovery
23%
5
571
Cases
-8%
4
15,830
Viral clearance
10%
2
130
RCTs
20%
12
1,003
RCT mortality
17%
7
588
Peer-reviewed
20%
36
35,616
High dose IV
21%
16
1,726
Symptomatic
24%
38
23,290
Prophylaxis
-3%
8
19,347
Early
43%
3
445
Late
25%
31
19,328
Vitamin C for COVID-19
c19vitaminc.com May 2022
Favors vitamin C
Favors control
after exclusions
• 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 2% 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.
• No treatment, vaccine, or intervention is 100%
available and effective for all variants. All practical, effective, and safe
means should be used.
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 .
Highlights
We show traditional outcome specific analyses and combined
evidence from all studies, incorporating treatment delay, a primary
confounding factor in COVID-19 studies.
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
Tau2 = 0.21, I2 = 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
ICU patients
Yüksel (ICU)
19%
0.81 [0.66-0.99]
death
31/42
40/44
ICU patients
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
ICU patients CT1
JamaliMo.. (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-A.. (RCT)
44%
0.56 [0.20-1.51]
death
5/40
9/40
CT1
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
CT1
Elhadi (ICU)
-12%
1.12 [0.96-1.31]
death
175/277
106/188
ICU patients
Suna
21%
0.79 [0.44-1.41]
death
17/153
24/170
Pourhoseingholi
13%
0.87 [0.63-1.19]
death
54/199
285/2,269
Li (ICU)
-11%
1.11 [0.79-1.54]
death
7/8
19/24
ICU patients
Vishnuram
54%
0.46 [0.24-0.86]
death
164/8,634
10/241
Özgünay (ICU)
9%
0.91 [0.63-1.30]
death
17/32
75/128
ICU patients
Tan
25%
0.75 [0.10-2.98]
death/int.
1/46
14/115
CT1
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
Shousha
94%
0.06 [0.01-0.37]
death
22/340
31/207
Tehrani (RCT)
87%
0.13 [0.01-2.25]
death
0/18
4/26
Majidi (DB RCT)
14%
0.86 [0.74-1.01]
death
26/31
67/69
ICU patients
Baguma
-48%
1.48 [0.41-4.70]
death
385 (n)
96 (n)
Yang (RCT)
15%
0.85 [0.68-1.06]
recov. time
10 (n)
10 (n)
LD2
Gavrielatou (ICU)
58%
0.42 [0.12-1.48]
death
2/10
49/103
ICU patients
Salehi (ICU)
10%
0.90 [0.65-1.25]
death
22/40
52/85
ICU patients
Coppock (RCT)
5%
0.95 [0.16-7.84]
progression
4/44
2/22
Hess (IPW)
20%
0.80 [0.40-1.60]
death
10/25
37/75
Tau2 = 0.15, I2 = 81.8%, p = 0.0019
Late treatment
25%
0.75 [0.63-0.90]
881/11,854
1,416/7,474
25% 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
Mahto
-26%
1.26 [0.63-2.28]
IgG+
34/140
59/549
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
Nimer
25%
0.75 [0.54-1.04]
hosp.
52/651
167/1,497
Shehab
4%
0.96 [0.46-1.99]
severe case
14/139
12/114
Tau2 = 0.03, I2 = 70.2%, p = 0.74
Prophylaxis
-3%
1.03 [0.87-1.22]
191/2,685
964/16,662
-3% improvement
All studies
18%
0.82 [0.73-0.92]
1,146/14,804
2,438/24,316
18% improvement
42 vitamin C COVID-19 studies
c19vitaminc.com May 2022
Tau2 = 0.07, I2 = 80.7%, p = 0.00096
Effect extraction pre-specified (most serious outcome, see appendix)
1 CT: study uses combined treatment 2 LD: comparison with low dose treatment
Favors vitamin C
Favors control
B
C
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.
Preclinical Research
An
In Vitro study supports the efficacy of vitamin C
[Goc ] .
Preclinical research is an important part of the development of
treatments, however results may be very different in clinical trials.
Preclinical results are not used in this paper.
Results
Figure 3 shows a visual overview of the results, with details in
Table 1 and
Table 2 .
Figure
4 ,
5 ,
6 ,
7 ,
8 ,
9 ,
10 ,
11 ,
12 ,
13 ,
14 , and
15
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, peer reviewed studies, and non-symptomatic vs. symptomatic results.
0
0.5
1
1.5+
ALL STUDIES
MORTALITY
VENTILATION
ICU ADMISSION
HOSPITALIZATION
RECOVERY
CASES
VIRAL CLEARANCE
RANDOMIZED CONTROLLED TRIALS
RCT MORTALITY
PEER-REVIEWED
HIGH DOSE IV
After Exclusions
ALL STUDIES
All
Prophylaxis
Early
Late
Vitamin C for COVID-19
C19VITAMINC.COM MAY 2022
Treatment time Number of studies reporting positive effects
Total number of studies Percentage 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
24
31
77.4%
25% improvement
RR 0.75 [0.63‑0.90]
p = 0.0019
Prophylaxis
4
8
50.0%
-3% improvement
RR 1.03 [0.87‑1.22]
p = 0.74
All studies
30
42
71.4%
18% improvement
RR 0.82 [0.73‑0.92]
p = 0.00096
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
Tau2 = 0.21, I2 = 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
ICU patients
Yüksel (ICU)
19%
0.81 [0.66-0.99]
death
31/42
40/44
ICU patients
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
ICU patients CT1
JamaliMo.. (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-A.. (RCT)
44%
0.56 [0.20-1.51]
death
5/40
9/40
CT1
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
CT1
Elhadi (ICU)
-12%
1.12 [0.96-1.31]
death
175/277
106/188
ICU patients
Suna
21%
0.79 [0.44-1.41]
death
17/153
24/170
Pourhoseingholi
13%
0.87 [0.63-1.19]
death
54/199
285/2,269
Li (ICU)
-11%
1.11 [0.79-1.54]
death
7/8
19/24
ICU patients
Vishnuram
54%
0.46 [0.24-0.86]
death
164/8,634
10/241
Özgünay (ICU)
9%
0.91 [0.63-1.30]
death
17/32
75/128
ICU patients
Tan
25%
0.75 [0.10-2.98]
death/int.
1/46
14/115
CT1
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
Shousha
94%
0.06 [0.01-0.37]
death
22/340
31/207
Tehrani (RCT)
87%
0.13 [0.01-2.25]
death
0/18
4/26
Majidi (DB RCT)
14%
0.86 [0.74-1.01]
death
26/31
67/69
ICU patients
Baguma
-48%
1.48 [0.41-4.70]
death
385 (n)
96 (n)
Yang (RCT)
15%
0.85 [0.68-1.06]
recov. time
10 (n)
10 (n)
LD2
Gavrielatou (ICU)
58%
0.42 [0.12-1.48]
death
2/10
49/103
ICU patients
Salehi (ICU)
10%
0.90 [0.65-1.25]
death
22/40
52/85
ICU patients
Coppock (RCT)
5%
0.95 [0.16-7.84]
progression
4/44
2/22
Hess (IPW)
20%
0.80 [0.40-1.60]
death
10/25
37/75
Tau2 = 0.15, I2 = 81.8%, p = 0.0019
Late treatment
25%
0.75 [0.63-0.90]
881/11,854
1,416/7,474
25% 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
Mahto
-26%
1.26 [0.63-2.28]
IgG+
34/140
59/549
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
Nimer
25%
0.75 [0.54-1.04]
hosp.
52/651
167/1,497
Shehab
4%
0.96 [0.46-1.99]
severe case
14/139
12/114
Tau2 = 0.03, I2 = 70.2%, p = 0.74
Prophylaxis
-3%
1.03 [0.87-1.22]
191/2,685
964/16,662
-3% improvement
All studies
18%
0.82 [0.73-0.92]
1,146/14,804
2,438/24,316
18% improvement
42 vitamin C COVID-19 studies
c19vitaminc.com May 2022
Tau2 = 0.07, I2 = 80.7%, p = 0.00096
Effect extraction pre-specified (most serious outcome, see appendix)
1 CT: study uses combined treatment 2 LD: comparison with low dose treatment
Favors vitamin C
Favors control
Figure 4. 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
Tau2 = 0.00, I2 = 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
ICU patients
Yüksel (ICU)
19%
0.81 [0.66-0.99]
31/42
40/44
ICU patients
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
JamaliMo.. (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-A.. (RCT)
44%
0.56 [0.20-1.51]
5/40
9/40
CT1
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
Elhadi (ICU)
-12%
1.12 [0.96-1.31]
175/277
106/188
ICU patients
Suna
21%
0.79 [0.44-1.41]
17/153
24/170
Pourhoseingholi
13%
0.87 [0.63-1.19]
54/199
285/2,269
Li (ICU)
-11%
1.11 [0.79-1.54]
7/8
19/24
ICU patients
Vishnuram
54%
0.46 [0.24-0.86]
164/8,634
10/241
Özgünay (ICU)
9%
0.91 [0.63-1.30]
17/32
75/128
ICU patients
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
Shousha
94%
0.06 [0.01-0.37]
22/340
31/207
Tehrani (RCT)
87%
0.13 [0.01-2.25]
0/18
4/26
Majidi (DB RCT)
14%
0.86 [0.74-1.01]
26/31
67/69
ICU patients
Baguma
-48%
1.48 [0.41-4.70]
385 (n)
96 (n)
Gavrielatou (ICU)
58%
0.42 [0.12-1.48]
2/10
49/103
ICU patients
Salehi (ICU)
10%
0.90 [0.65-1.25]
22/40
52/85
ICU patients
Hess (IPW)
20%
0.80 [0.40-1.60]
10/25
37/75
Tau2 = 0.17, I2 = 84.7%, p = 0.0038
Late treatment
26%
0.74 [0.61-0.91]
871/11,706
1,392/7,283
26% improvement
All studies
25%
0.75 [0.61-0.91]
872/11,754
1,392/7,333
25% improvement
27 vitamin C COVID-19 mortality results
c19vitaminc.com May 2022
Tau2 = 0.17, I2 = 84.2%, p = 0.0043
1 CT: study uses combined treatment
Favors vitamin C
Favors control
Figure 5. 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
JamaliMo.. (RCT)
-25%
1.25 [0.37-4.21]
5/30
4/30
Özgünay (ICU)
-1%
1.01 [0.79-1.29]
23/32
91/128
ICU patients
Hess (IPW)
40%
0.60 [0.28-1.00]
18/25
54/75
Tau2 = 0.07, I2 = 61.4%, p = 0.27
Late treatment
18%
0.82 [0.57-1.16]
58/162
164/308
18% improvement
All studies
18%
0.82 [0.57-1.16]
58/162
164/308
18% improvement
4 vitamin C COVID-19 mechanical ventilation results
c19vitaminc.com May 2022
Tau2 = 0.07, I2 = 61.4%, p = 0.27
Favors vitamin C
Favors control
Figure 6. 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)
ICU patients CT1
Improvement, RR [CI]
Treatment
Control
Hakamifard (RCT)
46%
0.54 [0.14-2.08]
3/38
5/34
CT1
Suna
-2%
1.02 [0.46-2.24]
11/153
12/170
Simsek
10%
0.90 [0.55-1.46]
18/58
28/81
Hess (IPW)
27%
0.73 [0.41-1.04]
22/25
63/75
Tau2 = 0.01, I2 = 36.8%, p = 0.048
Late treatment
15%
0.85 [0.72-1.00]
54/284
108/370
15% improvement
All studies
15%
0.85 [0.72-1.00]
54/284
108/370
15% improvement
5 vitamin C COVID-19 ICU results
c19vitaminc.com May 2022
Tau2 = 0.01, I2 = 36.8%, p = 0.048
1 CT: study uses combined treatment
Favors vitamin C
Favors control
Figure 7. 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
Tau2 = 0.00, I2 = 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
JamaliMo.. (RCT)
-31%
1.31 [1.03-1.66]
hosp. time
30 (n)
30 (n)
Hamidi-A.. (RCT)
38%
0.62 [0.45-0.86]
hosp. time
40 (n)
40 (n)
CT1
Hakamifard (RCT)
1%
0.99 [0.91-1.07]
hosp. time
38 (n)
34 (n)
CT1
Tehrani (RCT)
18%
0.82 [0.60-1.13]
hosp. time
18 (n)
26 (n)
Tau2 = 0.04, I2 = 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
Nimer
25%
0.75 [0.54-1.04]
hosp.
52/651
167/1,497
Tau2 = 0.00, I2 = 0.0%, p = 0.053
Prophylaxis
24%
0.76 [0.58-1.00]
60/783
189/1,792
24% improvement
All studies
14%
0.86 [0.73-1.02]
62/1,032
192/2,047
14% improvement
8 vitamin C COVID-19 hospitalization results
c19vitaminc.com May 2022
Tau2 = 0.03, I2 = 74.1%, p = 0.091
1 CT: study uses combined treatment
Favors vitamin C
Favors control
Figure 8. 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
Tau2 = 0.00, I2 = 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
ICU patients CT1
Improvement, RR [CI]
Treatment
Control
Tan
73%
0.27 [0.09-0.61]
7/46
41/115
CT1
Coppock (RCT)
5%
0.95 [0.16-7.84]
4/44
2/22
Tau2 = 0.13, I2 = 23.9%, p = 0.028
Late treatment
59%
0.41 [0.19-0.91]
13/100
46/147
59% improvement
All studies
66%
0.34 [0.20-0.58]
17/155
58/202
66% improvement
4 vitamin C COVID-19 progression results
c19vitaminc.com May 2022
Tau2 = 0.00, I2 = 0.0%, p < 0.0001
1 CT: study uses combined treatment
Favors vitamin C
Favors control
Figure 9. 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
Tau2 = 0.00, I2 = 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
Yang (RCT)
15%
0.85 [0.68-1.06]
recov. time
10 (n)
10 (n)
LD1
Coppock (RCT)
22%
0.78 [0.61-0.98]
no disch.
31/44
20/22
Tau2 = 0.00, I2 = 0.0%, p < 0.0001
Late treatment
23%
0.77 [0.69-0.86]
31/129
20/107
23% improvement
All studies
23%
0.77 [0.70-0.84]
100/339
66/232
23% improvement
5 vitamin C COVID-19 recovery results
c19vitaminc.com May 2022
Tau2 = 0.00, I2 = 0.0%, p < 0.0001
1 LD: comparison with low dose treatment
Favors vitamin C
Favors control
Figure 10. 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
Tau2 = 0.04, I2 = 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 May 2022
Tau2 = 0.04, I2 = 83.4%, p = 0.52
Favors vitamin C
Favors control
Figure 11. Random effects meta-analysis for cases.
0
0.25
0.5
0.75
1
1.25
1.5