title: Effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections in young children in Brazil.
abstract: A beneficial effect of periodic vitamin A supplementation on childhood mortality has been demonstrated, but the effect on morbidity is less clear. We investigated the effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections (ALRI) in children from northeastern Brazil in a randomised, double-blind, placebo-controlled community trial. 1240 children aged 6-48 months were assigned vitamin A or placebo every 4 months for 1 year. They were followed up at home three times a week, and data about the occurrence and severity of diarrhoea and ALRI were collected. Any child with cough and respiratory rate above 40 breaths per min was visited by a paediatrician. The overall incidence of diarrhoea episodes was significantly lower in the vitamin-A-supplemented group than in the placebo group (18.42 vs 19.58 x 10(-3) child-days; rate ratio 0.94 [95% Cl 0.90-0.98]). The benefit of supplementation was greater as regards severe episodes of diarrhoea; the incidence was 20% lower in the vitamin A group than in the placebo group (rate ratio 0.80 [0.65-0.98]). With the standard definition of diarrhoea (> or = 3 liquid or semi-liquid stools in 24 h) the effect of vitamin A on mean daily prevalence did not reach significance, but as the definition of diarrhoea was made more stringent (increasing number of stools per day), a significant benefit became apparent, reaching for diarrhoea with 6 or more liquid or semi-liquid stools in 24 h a 23% lower prevalence. We found no effect of vitamin A supplementation on the incidence of ALRI. The reduction in severity of diarrhoea may be the most important factor in the lowering of mortality by vitamin A supplementation.
authors.affiliation: Department of Preventive Medicine, Federal University of Bahla, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Barreto
authors.forename: L M
authors.initials: LM
authors.lastname: Santos
authors.forename: A M
authors.initials: AM
authors.lastname: Assis
authors.forename: M P
authors.initials: MP
authors.lastname: Araújo
authors.forename: G G
authors.initials: GG
authors.lastname: Farenzena
authors.forename: P A
authors.initials: PA
authors.lastname: Santos
authors.forename: R L
authors.initials: RL
authors.lastname: Fiaccone
mesh_terms: D000208:Acute Disease; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology / Q000517:prevention & control*; D003968:Diarrhea, Infantile / Q000453:epidemiology / Q000517:prevention & control; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000517:prevention & control*; D014801:Vitamin A / Q000008:administration & dosage*
chemical_list: D014801:Vitamin A