Respiratory infections reduce the growth response to vitamin A supplementation in a randomized controlled trial.
BACKGROUND
Studies on the effect of vitamin A supplementation on growth have yielded various results. It is possible that such growth is dependent on the burden of infectious diseases in the population.


METHODS
We analysed data from a randomized, double-masked, placebo-controled trial to examine the role of respiratory infections and diarrhoea in modifying the growth response to vitamin A supplementation. A single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months, and 4430 child treatment cycles were used in this analysis.


RESULTS
Vitamin A supplementation modestly improved linear but not ponderal growth of children who experienced little respiratory infection and especially of those who had vitamin A intake below the normative requirement (<400 RE/day). Children who received vitamin A and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height than the placebo group, but those with > or =21.5% of days of respiratory infection did not show a significant growth response to vitamin A supplementation. Children who experienced no respiratory infection and had vitamin A intake <400 RE/day benefited most, gaining 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height compared to the placebo group. Diarrhoea was associated with poorer growth, but did not significantly modify the effect of vitamin A supplementation on growth.


CONCLUSIONS
Vitamin A supplementation improves the linear growth of children who have a low intake of vitamin A but this impact is muted with increasing levels of respiratory infections.
Hadi
H
H
Department of Public Health, Faculty of Medicine, Gadjah Mada University, Yogyakarta, Indonesia. givi@yogya.wasantara.net.id
Stoltzfus
R J
RJ
Moulton
L H
LH
Dibley
M J
MJ
West
K P
KP
D001827:Body Height / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002675:Child, Preschool; D016001:Confidence Intervals; D003967:Diarrhea / Q000150:complications* / Q000175:diagnosis; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006130:Growth Disorders / Q000150:complications / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D008297:Male; D012016:Reference Values; D012141:Respiratory Tract Infections / Q000150:complications* / Q000175:diagnosis; D016896:Treatment Outcome; D014801:Vitamin A / Q000008:administration & dosage*
D014801:Vitamin A