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.