112 The World Health Report 2002 based on an estimation of the amount of recommended daily allowance anticipated to be taken in from other sources and the average per capita intake of sugar in different settings A trend analysis of a number of different fortification programmes in central America shows relative reduction of about 60% in the prevalence of vitamin A deficiency associated with the introduction of fortification (33). Intervention includes provision of guidelines for qual ty control of sugar fortification in the mills, regular visits to mills by inspectors, and regular sampling and testing of sugar taken from mills, markets and homes for vitamin A content Samples from homes are taken opportunistically during mass surveys carried out for other Results As with iron, vitamin A fortification is more cost-effective than supplementation in regions, because of its lower costs. Supplementation will, however, have a substantia large benefit in terms of population health- approximately twice as high as fortification although at a higher cost. It is also very cost-effective in its own right. Both remain either cost-effective or very cost-effective in all regions included in the analysis when coverage is increased to the maximum possible level ZINC DEFICIENCY Interventions Zinc supplementation. During one of the first immunization contacts in infancy, the ealth worker prescribes zinc gluconate or sulfate(10 mg in solution) as part of a routine Thereafter, the zinc solution is administered by a carer at home daily to every child until the child reaches five years of age. Effectiveness of the intervention is adjusted by expected adherence for medications needing to be taken daily. Zinc fortification The intervention has the same characteristics as for Vitamin A fortifi cation except the food vehicle is wheat, not sugar. Note that in the absence of effectiveness data,the assumption has been made that zinc fortification is half as efficacious as zinc supplementation, consistent with that made for iron fortificatic As with iron and vitamin A, zinc supplementation and fortification both prove to be very cost-effective interventions in all subregions. Fortification is more cost-effective than sup plementation and is also slightly more cost-effective than vitamin A supplementation in most regions evaluated. Even though zinc fortification is very cost-effective, erall impact on population health of this intervention is lower than the gains associated with vitamin a fortification ons where vitamin a deficiency is a problem. It should, of course, be remembered that no large-scale zinc fortification programme has yet been car- ried out, so the results are based on the effect on health of assumed increases in zinc intake DTHER INDIVIDUAL- BASED INTERVENTIONS FOCUSING ON CHILDREN UNDER FIVE YEARS OF AGE Interventions Although not strictly risk-reducing strategies, two ways of reducing the risk of death associated with the risk factors outlined above are considered here Oral rehydration therapy Health workers are trained to use an algorithm for the as- sessment and management of dehydration caused by diarrhoea in children under five years of age Children brought to a health facility with watery stools are assessed for signs of112 The World Health Report 2002 based on an estimation of the amount of recommended daily allowance anticipated to be taken in from other sources and the average per capita intake of sugar in different settings. A trend analysis of a number of different fortification programmes in central America shows a relative reduction of about 60% in the prevalence of vitamin A deficiency associated with the introduction of fortification (33). Intervention includes provision of guidelines for qual￾ity control of sugar fortification in the mills, regular visits to mills by inspectors, and regular sampling and testing of sugar taken from mills, markets and homes for vitamin A content. Samples from homes are taken opportunistically during mass surveys carried out for other purposes. Results As with iron, vitamin A fortification is more cost-effective than supplementation in all regions, because of its lower costs. Supplementation will, however, have a substantially large benefit in terms of population health – approximately twice as high as fortification – although at a higher cost. It is also very cost-effective in its own right. Both remain either cost-effective or very cost-effective in all regions included in the analysis when coverage is increased to the maximum possible level. ZINC DEFICIENCY Interventions Zinc supplementation. During one of the first immunization contacts in infancy, the health worker prescribes zinc gluconate or sulfate (10 mg in solution) as part of a routine. Thereafter, the zinc solution is administered by a carer at home daily to every child until the child reaches five years of age. Effectiveness of the intervention is adjusted by expected adherence for medications needing to be taken daily. Zinc fortification. The intervention has the same characteristics as for Vitamin A fortifi￾cation except the food vehicle is wheat, not sugar. Note that in the absence of effectiveness data, the assumption has been made that zinc fortification is half as efficacious as zinc supplementation, consistent with that made for iron fortification. Results As with iron and vitamin A, zinc supplementation and fortification both prove to be very cost-effective interventions in all subregions. Fortification is more cost-effective than sup￾plementation and is also slightly more cost-effective than vitamin A supplementation in most regions evaluated. Even though zinc fortification is very cost-effective, the overall impact on population health of this intervention is lower than the gains associated with vitamin A fortification in regions where vitamin A deficiency is a problem. It should, of course, be remembered that no large-scale zinc fortification programme has yet been car￾ried out, so the results are based on the effect on health of assumed increases in zinc intake. OTHER INDIVIDUAL-BASED INTERVENTIONS FOCUSING ON CHILDREN UNDER FIVE YEARS OF AGE Interventions Although not strictly risk-reducing strategies, two ways of reducing the risk of death associated with the risk factors outlined above are considered here. Oral rehydration therapy. Health workers are trained to use an algorithm for the as￾sessment and management of dehydration caused by diarrhoea in children under five years of age. Children brought to a health facility with watery stools are assessed for signs of