EFFECT OF VITAMIN-A SUPPLEMENTATION ON DIARRHEA AND ACUTE LOWER-RESPIRATORY-TRACT INFECTIONS IN YOUNG-CHILDREN IN BRAZIL

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 diar rhoea and acute lower-respiratoty-tract infections (ALRI) in children from northeastern Brazil in a randomised, double-blind, placebo-contro lled community trial. 1240 children aged 6-48 months were assigned vit amin 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 respirato ry rate above 40 breaths per min was visited by a paediatrician. The o verall 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 0.90-0.9 8]). The benefi t of supplementation was greater as regards severe episodes of diarrho ea; the incidence was 20% lower in the vitamin A group than in the pla cebo group (rate ratio 0.80 [0.65-0.98]). With the standard definition of diarrhoea (greater than or equal to 3 liquid or semi-liquid stools in 24 h) the effect of vitamin A on mean daily prevalence did not rea ch significance, but as the definition of diarrhoea was made more stri ngent (increasing number of stools per day), a significant benefit bec ame apparent, reaching for diarrhoea with 6 or more liquid or semi-liq uid stools in 24 h a 23% lower prevalence. We found no effect of vitam in A supplementation on the incidence of ALRI. The reduction in severi ty of diarrhoea may be the most important factor in the lowering of mo rtality by vitamin A supplementation.