Does vitamin A supplementation protect schoolchildren from acquiring soil-transmitted helminthiasis? A randomized controlled trial

Background: despite the intensive global efforts to control intestinal parasitic infections,the prevalence of soil-transmitted helminth (sth) infections is still very high in many developing countries particularly among children in rural areas.methods. a randomized,double-blind,placebo-controlled trial was conducted on 250 aboriginal schoolchildren in malaysia to investigate the effects of a single high-dose of vitamin a supplementation (200 000 iu) on sth reinfection. the effect of the supplement was assessed at 3 and 6 months after receiving interventions; after a complete 3-day deworming course of 400 mg/daily of albendazole tablets.results: almost all children (98.6%) were infected with at least one sth species. the overall prevalence of ascariasis,trichuriasis and hookworm infection was 67.8%,95.5% and 13.4%,respectively. reinfection rates of ascaris,trichuris and hookworm were high; at 6 months,assessment reached 80% of the prevalence reported before treatment. there were no significant differences in the reinfection rates and intensities of sth between vitamin a supplemented-children and those who received placebo at 3 and 6 months (p > 0.05).conclusions: vitamin a supplementation showed no protective effect against sth reinfection and this could be due to the high endemicity of sth in this community. long-term interventions to reduce poverty will help significantly in reducing this continuing problem and there is no doubt that reducing intestinal parasitic infection would have a positive impact on the health,nutrition and education of these children. trial registration. this trial was registered at clinicaltrials.gov as nct00936091. © 2014al-mekhlafi et al.; licensee biomed central ltd.