Impact of vitamin A supplementation to rural children on morbidity due to diarrhoea

Background & objectives : A number of studies have shown the association be tween vitamin A deficiency and the increased risk of diarrhoeal and other c hildhood morbidities and mortality. However, some studies have raised contr oversies regarding the reduction of the incidence of diarrhoea after vitami n A supplementation to children. This study was undertaken to evaluate the effectiveness of vitamin A supplementation to young rural children in reduc ing the incidence of diarrhoea. Methods : A double-blind randomized intervention trial was carried out amon gst 404 rural children between 6-59 months of age to assess the impart of v itamin A supplementation on morbidity due to diarrhoea. Children aged 6-59 months were enrolled and allocated to receive either 200,000 or 50,000 IU o f vitamin A and the same dose was repeated after six months. Morbidity due to diarrhoea was observed by twice-a-week household surveillance, during th e subsequent one year of follow up. The incidence of diarrhoea was compared between the two supplemented groups. In addition, the overall incidence of diarrhoea in the two supplemented groups was also compared with the incide nce observed during the year preceding supplementation. Results : The incidence of diarrhoea was similar in the two supplemented gr oups (Incidence Rate Ratio = 1.05, 95% C.I. 0.79-1:401. However, the overal l incidence of diarrhoea among all the children in the two supplemented gro ups (0.56 episodes/child/year) was significantly lower than the incidence b efore supplementation (1.15 episodes/child/year). The Incidence Rate Ratio was 0.49 with 95%, C.I. 0.40-0.59. Interpretation & conclusions : The results of this study indicate that vita min A supplementation in a dose of 200,000 IU, has no additional advantage over 50,000 IU, at least when the aim is to reduce the incidence of diarrho ea. For control of morbidity due to diarrhoea, vitamin A supplementation in a dose of 50,000 IU every six months appears to be adequate, cost effectiv e and suitable for younger children.