Cochrane · systematic review · CD013134
Vitamin C supplementation for prevention and treatment of pneumonia
Padhani, ZA, Moazzam, Z, Ashraf, A, et al. · Cochrane Database of Systematic Reviews · 2021 · Cochrane Library
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
8
current version
GRADE rated
3
No studies
5
Included studies
NR
No studies 5 · 62.5%Ungraded 0 · 0%Very low 3 · 37.5%Low 0 · 0%Moderate 0 · 0%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Questions and results
Current version onlyVitamin C compared to placebo for prevention of pneumonia
Population: school‐aged children (6 to 15 years) and marine corps recruits (mean age 18.5 years)
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Incidence of pneumonia Defined as patient admitted to hospital with a diagnosis of pneumonia Dose: 2 g per day Vitamin C vs placebo | RR 0.15 [0.02, 1.2] | 1 study · 674 participants | Very low Downgraded: risk of bias, imprecision |
Prevalance of pneumonia Vitamin C vs placebo | no estimate extracted | NR | No studies |
Mortality due to pneumonia Vitamin C vs placebo | no estimate extracted | NR | No studies |
Adverse effects (urticaria) Defined as participants reporting urticaria (hives) Dose: 2 g per day Vitamin C vs placebo | RR 3.11 [0.13, 76.03] | 1 study · 674 participants | Very low Downgraded: risk of bias, imprecision |
Vitamin C compared to placebo for treatment of pneumonia
Population: children under 5 years of age
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Duration of illness Defined as number of days until illness improved Dose: 200 mg daily Vitamin C vs placebo | no estimate extracted | NR | Very low Downgraded: risk of bias, imprecision |
Clinical cure rate Vitamin C vs placebo | no estimate extracted | NR | No studies |
Mortality due to pneumonia Vitamin C vs placebo | no estimate extracted | NR | No studies |
Adverse effects Vitamin C vs placebo | no estimate extracted | NR | No studies |
Vitamin C compared to placebo for prevention of pneumonia
Population: school‐aged children (10 to 15 years) and marine corps recruits
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Incidence of pneumonia Defined as patient admitted to hospital with a diagnosis of pneumonia Dose: 2 g per day Vitamin C vs placebo | RR 0.46 [0.06, 3.61] | 2 studies · 736 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Prevalance of pneumonia Vitamin C vs placebo | no estimate extracted | NR | No studies |
Mortality due to pneumonia Vitamin C vs placebo | no estimate extracted | NR | No studies |
Adverse effects (urticaria) Defined as participants reporting urticaria (hives) Dose: 2 g per day Vitamin C vs placebo | RR 3.11 [0.13, 76.03] | 1 study · 674 participants | Very low Downgraded: risk of bias, imprecision |
Vitamin C compared to placebo for treatment of pneumonia
Population: children under 5 years of age and adults
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Duration of illness Defined as number of days until illness improved Dose: 200 mg daily and 2 g daily Vitamin C vs placebo | no estimate extracted | 1 study · 130 participants | Very low Downgraded: risk of bias, imprecision |
Clinical cure rate Vitamin C vs placebo | no estimate extracted | NR | No studies |
Mortality due to pneumonia Defined as deaths due to pneumonia Dose: 200 mg Vitamin C vs placebo | RR 0.21 [0.03, 1.66] | 1 study · 57 participants | Very low Downgraded: risk of bias, imprecision |
Adverse effects Vitamin C vs placebo | no estimate extracted | NR | No studies |