Xerophthalmia has been found to be an important cause of blindness in the Philippines. An earlier study had investigated its prevalence and epidemiology on the island of Cebu. The research now presented consists of an evaluation of the relative effectiveness of three different intervention strategies to control vitamin A deficiency in Cebu. These interventions were 1) a public health and horticulture intervention, 2) the provision of 200,000 IU of vitamin A to children every 6 months (the "capsule intervention"), and 3) the fortification of monosodium glutamate with vitamin A. A total of 12 areas or barangays were included. Each intervention was monitored in four different barangays, two urban and two rural, for almost 2 years. Similar examinations were performed before and after the interventions. The monosodium glutamate fortification was the only intervention that resulted both in a significant reduction in clinical signs of xerophthalmia and in a significant rise in serum vitamin A levels. Fortification is now being planned in three Philippine provinces.