Vitamin E and vitamin C supplementation does not improve the clinical course of measles with pneumonia in children: a controlled trial

Vitamin C supplementation for prevention and treatment of pneumonia

BACKGROUND

According to the Global Burden of Disease Study 2015, lower respiratory tract infection is the leading cause of infectious disease death, and the fifth most common cause of death overall. Vitamin C has a role in modulating resistance to infectious agents, therefore vitamin C supplementation may be important in preventing and treating pneumonia.

OBJECTIVES

To assess the impact of vitamin C supplementation to prevent and treat pneumonia in children and adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed, CINAHL, LILACS, Web of Science, and two trials registers to 4 March 2020. We also checked references to identify additional studies. We did not apply any publication status or language filters.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (studies using allocation methods that are not random, e.g. date of birth, medical record number) assessing the role of vitamin C supplementation in the prevention and treatment of pneumonia in children and adults compared to control or placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included five studies in the review and identified two ongoing studies. The five included studies involved a total of 2655 participants; two studies were RCTs and three were quasi-RCTs. The included studies were conducted in one high-income country (USA) and three lower-middle-income countries (Bangladesh and Pakistan). Three studies were conducted in hospital inpatient settings, one in school, and one in a military training centre. Three studies included children under five years of age, one study included school-aged children, and one study included adult participants. Two studies assessed the effect of vitamin C supplementation for pneumonia prevention; and three studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment. For pneumonia prevention, the included studies provided supplementation in doses of 1 g daily for 14 weeks, 2 g daily for 8 weeks, and 2 g daily for 14 weeks. For pneumonia treatment, the included studies provided vitamin C supplementation in doses of 125 mg daily and 200 mg daily until the symptoms resolved or discharge, as an adjunct to the pneumonia treatment. Overall, the included studies were judged to be at either high or unclear risk of bias for random sequence generation, allocation concealment, and blinding; and the evidence certainty was very low. Two studies assessed the effect of vitamin C supplementation for pneumonia prevention; we judged the certainty of the evidence as very low. We are uncertain about the effect of vitamin C supplementation on pneumonia incidence and adverse events (urticaria). None of the included studies reported other primary outcomes (pneumonia prevalence and mortality) or any of the secondary outcomes. Three studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment; we judged the certainty of the evidence as very low. We are uncertain of the effect of vitamin C supplementation on duration of illness and hospitalisation. None of the included studies reported other primary or secondary outcomes.

AUTHORS' CONCLUSIONS

Due to the small number of included studies and very low certainty of the existing evidence, we are uncertain of the effect of vitamin C supplementation for the prevention and treatment of pneumonia. Further good-quality studies are required to assess the role of vitamin C supplementation in the prevention and treatment of pneumonia.

Vitamin C supplementation for prevention and treatment of pneumonia

BACKGROUND

According to the Global Burden of Disease Study 2015, lower respiratory tract infection is the leading cause of infectious disease death, and the fifth most common cause of death overall. Vitamin C has a role in modulating resistance to infectious agents, therefore vitamin C supplementation may be important in preventing and treating pneumonia.

OBJECTIVES

To assess the impact of vitamin C supplementation to prevent and treat pneumonia in children and adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed, CINAHL, LILACS, Web of Science, and two trials registers to 4 March 2020. We also checked references to identify additional studies. We did not apply any publication status or language filters.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (studies using allocation methods that are not random, e.g. date of birth, medical record number) assessing the role of vitamin C supplementation in the prevention and treatment of pneumonia in children and adults compared to control or placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included seven studies in the review and identified two ongoing studies. The seven included studies involved a total of 2774 participants; five studies were RCTs and two were quasi-RCTs. The included studies were conducted in high-income countries (UK, USA and Chile) and lower-middle-income countries (Bangladesh and Pakistan). Four studies were conducted in hospital inpatient settings, two in schools, and one in a military training centre. Three studies included children under five years of age, two school-aged children, one adult participants, and one older participants aged 60 to 90 years. Two studies assessed the effect of vitamin C supplementation for pneumonia prevention; four studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment; and one study assessed the role of vitamin C for both prevention and treatment of pneumonia. For pneumonia prevention, the included studies provided supplementation in doses of 500 mg daily for 14 weeks, 2 g daily for 8 weeks, and 2 g daily for 12 weeks. For pneumonia treatment, the included studies provided vitamin C supplementation in doses of 125 mg daily (until discharge), 200 mg for 4 weeks, and 200 mg until discharge, as an adjunct to the pneumonia treatment. We assessed the included studies as at overall either high or unclear risk of bias for random sequence generation, allocation concealment, and blinding. We judged the quality of the evidence as very low. Three studies assessed the effect of vitamin C supplementation for pneumonia prevention; we judged the quality of the evidence as very low. We are uncertain about the effect of vitamin C supplementation on pneumonia incidence (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.06 to 3.61; 2 studies, 736 participants; I² = 75%; very low-quality evidence) and adverse events (urticaria) (RR 3.11, 95% CI 0.13 to 76.03; 1 study, 674 participants; very low-quality evidence). No included studies reported our other primary outcomes (pneumonia prevalence and mortality) or any of our secondary outcomes. Five studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment; we judged the quality of the evidence as very low. One study reported a decrease in the duration of illness in the vitamin C supplementation group (3.4 days ± 2.54) compared to the control group (4.5 days ± 2.35), and one study reported a decrease in number of days required for improvement in oxygen saturation (1.03 days ± 0.16 versus 1.14 days ± 1.0) and respiratory rate (3.61 days ± 1.50 versus 4.04 days ± 1.62) in the vitamin C supplementation group compared to the control group. We are uncertain of the effect of vitamin C supplementation on mortality due to pneumonia (RR 0.21, 95% CI 0.03 to 1.66; 1 study, 57 participants; very low-quality evidence). One study reported that the mean duration of hospital stay was 6.75 days amongst children in the vitamin C supplementation group and 7.75 days in the control group; another study reported a lower mean duration of hospital stay in the vitamin C supplementation group compared to the control group (109.55 hours ± 27.89 versus 130.64 hours ± 41.76).

AUTHORS' CONCLUSIONS

Due to the small number of included studies and very low quality of the existing evidence, we are uncertain of the effect of vitamin C supplementation for the prevention and treatment of pneumonia. Further good-quality studies are required to assess the role of vitamin C supplementation in the prevention and treatment of pneumonia.

Vitamin C for preventing and treating pneumonia

BACKGROUND

Pneumonia is one of the most common serious infections, causing two million deaths annually among young children in low-income countries. In high-income countries pneumonia is most significantly a problem of the elderly.

OBJECTIVES

To assess the prophylactic and therapeutic effects of vitamin C on pneumonia.

SEARCH METHODS

We searched CENTRAL 2013, Issue 3, MEDLINE (1950 to March week 4, 2013), EMBASE (1974 to April 2013) and Web of Science (1955 to April 2013).

SELECTION CRITERIA

To assess the therapeutic effects of vitamin C, we selected placebo-controlled trials. To assess prophylactic effects, we selected controlled trials with or without a placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently read the trial reports and extracted data.

MAIN RESULTS

We identified three prophylactic trials which recorded 37 cases of community-acquired pneumonia in 2335 people. Only one was satisfactorily randomised, double-blind and placebo-controlled. Two trials examined military recruits and the third studied boys from "lower wage-earning classes" attending a boarding school in the UK during World War II. Each of these three trials found a statistically significant (80% or greater) reduction in pneumonia incidence in the vitamin C group. We identified two therapeutic trials involving 197 community-acquired pneumonia patients. Only one was satisfactorily randomised, double-blind and placebo-controlled. That trial studied elderly patients in the UK and found lower mortality and reduced severity in the vitamin C group; however, the benefit was restricted to the most ill patients. The other therapeutic trial studied adults with a wide age range in the former Soviet Union and found a dose-dependent reduction in the duration of pneumonia with two vitamin C doses. We identified one prophylactic trial recording 13 cases of hospital-acquired pneumonia in 37 severely burned patients; one-day administration of vitamin C had no effect on pneumonia incidence. The identified studies are clinically heterogeneous which limits their comparability. The included studies did not find adverse effects of vitamin C.

AUTHORS' CONCLUSIONS

The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have a high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied, especially in patients with low plasma vitamin C levels. The current evidence is too weak to advocate prophylactic use of vitamin C to prevent pneumonia in the general population. Nevertheless, therapeutic vitamin C supplementation may be reasonable for pneumonia patients who have low vitamin C plasma levels because its cost and risks are low.

Micronutrient concentrations in respiratory syncytial virus and human metapneumovirus in Yemeni children

BACKGROUND

Acute respiratory infections (ARI) cause significant childhood mortality. Nutritional homeostasis, particularly micronutrient levels, is important in modulating response to infection. More information is required regarding micronutrient levels in ARI viral infections, especially newly identified viruses such as human metapneumovirus (HMPV).

AIM

To describe zinc, copper, selenium and vitamins A and E concentrations in children with respiratory syncytial virus (RSV) and/or HMPV in relation to levels of C-reactive protein (CRP).

METHODS

The presence of RSV/HMPV in nasopharyngeal aspirates (NPA) was identified in 246 children using RTPCR. Zinc, copper, selenium and vitamins A and E concentrations were measured using inductive coupled plasma mass spectrometry and high performance liquid chromatography.

RESULTS

183 children had RSV, 39 had HMPV and 24 were co-infected. Zinc concentrations were lower in children with HMPV than in children with RSV or RSV/HMPV co-infection. Copper concentrations were lower in children with RSV than in children with RSV/HMPV or HMPV and zinc/copper ratios were lower in children with HMPV/RSV or RSV than in children with HMPV alone. Retinol and a alpha-tocopherol were lower in children with RSV than in children with HMPV. Most children had low selenium concentrations. Children with RSV and raised CRP (>5 mg/L) had higher copper and lower zinc/copper ratios than those with low CRP (< or =5 mg/L). Children with HMPV and raised CRP had higher copper and lower zinc concentrations than children with low CRP. Children with RSV/HMPV and raised CRP had higher copper concentrations. Children with RSV/HMPV and raised CRP had higher a alpha-tocopherol concentrations.

CONCLUSION

The profiles of micronutrients differ in children with RSV and HMPV and are confounded by CRP. These results may guide strategies for micronutrient supplementation in ARI.

Vitamin C for preventing and treating pneumonia

BACKGROUND

Pneumonia is one of the most common serious infections, causing two million deaths annually among young children in developing countries. In developed countries pneumonia is most significantly a problem of the elderly.

OBJECTIVES

To assess the prophylactic and therapeutic effects of vitamin C on pneumonia.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), OLD MEDLINE (1950 TO 1965), MEDLINE (1966 to February Week 2, 2006), EMBASE (1974 to March 2006), Web of Science (1945 to February 2006) and reference lists of reviews and articles.

SELECTION CRITERIA

To assess the therapeutic effects of vitamin C, we selected placebo-controlled trials. To assess prophylactic effects, we selected controlled trials with or without a placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently read the trial reports and extracted data.

MAIN RESULTS

We identified three prophylactic trials which recorded 37 cases of pneumonia in 2,335 people. Only one was satisfactorily randomised, double-blind and placebo-controlled. Two trials examined military recruits and the third studied boys from "lower wage-earning classes" attending a boarding school in the UK during World War II. Each of these trials found a statistically significant (80% or greater) reduction in pneumonia incidence in the vitamin C group. We identified two therapeutic trials involving 197 pneumonia patients. Only one was satisfactorily randomised, double-blind and placebo-controlled. One studied elderly patients in the UK which found lower mortality and reduced respiratory symptom scores in the vitamin C group; however, the benefit was restricted to the most ill patients. The other studied adults (with a wide age range) in the former Soviet Union and found a dose-dependent reduction in the time to recovery with two vitamin C doses.

AUTHORS' CONCLUSIONS

The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied especially in patients with low plasma vitamin C levels. The current evidence is too weak to advocate widespread prophylactic use of vitamin C to prevent pneumonia in the general population. However, therapeutic vitamin C supplementation may be reasonable for pneumonia patients who have low vitamin C plasma levels because its cost and risks are low.