Acute respiratory infections, mostly in the form of pneumonia, are the leading cause of death in children under five years of age living in low-income countries. Vitamin A supplementation has been found to reduce mortality and the severity of respiratory infections in children with measles. This updated review was undertaken to assess the effectiveness of vitamin A adjunctive therapy in children with non-measles respiratory infections, particularly pneumonia.
We found six trials (1740 participants) that used vitamin A adjunctive therapy in children with non-measles pneumonia. There was no significant reduction in mortality or duration of hospital stay. Supplementary high-dose vitamin A may result in a worsening of the disease, and low-dose vitamin A significantly reduces the recurrence of bronchopneumonia. Moderate-dose vitamin A significantly reduces the time to remission of signs in children with normal serum retinol. The possible reason of the lack of benefit of vitamin A in non-measles pneumonia is that the effects of vitamin A may be disease-specific, with vitamin A only being effective when pneumonia is complicated with measles. Further high-quality research is required.
The evidence does not suggest a significant reduction in mortality, measures of morbidity, nor an effect on the clinical course of pneumonia with vitamin A adjunctive treatment in children with non-measles pneumonia. However, not all studies measured all outcomes, which limited the number of studies that could be incorporated into the meta-analyses, so that there may have been a lack of statistical power to detect statistically significant differences.
Acute respiratory infections, mostly in the form of pneumonia, are the leading causes of death in children under five years of age in low-income countries. Some clinical trials have demonstrated that vitamin A supplementation reduces the severity of respiratory infections and mortality in children with measles.
To determine whether adjunctive vitamin A is effective in children diagnosed with non-measles pneumonia.
We searched The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL 2010, issue 3) which contains the Acute Respiratory Infections Group's Specialised Regsiter, MEDLINE (1996 to July week 3, 2010), EMBASE (1990 to August 2010), LILACS (1985 to August 2010), CINAHL (1990 to August 2010), Biological Abstracts (1990 to August 2010), Current Contents (1990 to August 2010) and the Chinese Biomedicine Database (CBM) (1994 to June 2010).
Only parallel-arm, randomized controlled trials (RCTs) and quasi-RCTs, in which children (younger than 15 years of age) with non-measles pneumonia were treated with adjunctive vitamin A, were included.
Two review authors independently extracted data and assessed trial quality. Study authors were contacted for additional information.
Six trials involving 1740 children were included. There was no significant reduction in mortality associated with pneumonia in children treated with vitamin A compared to those who were not (pooled odds ratio (OR) 1.29; 95% confidence interval (CI) 0.63 to 2.66). Also, there was no statistically significant difference in duration of hospital stay (mean difference (MD) 0.08; 95% CI -0.43 to 0.59). Disease severity after supplementary high-dose vitamin A was significantly worse compared with placebo. However, low-dose vitamin A significantly reduced the recurrence rate of bronchopneumonia (OR 0.12; 95% CI 0.03 to 0.46). Moderate vitamin A significantly reduced the time to remission of signs in children with normal serum retinol (> 200 ug/L).