AbstractRecent investigations conducted in Indonesia have identified an important role for adequate vitamin A nutriture in preventing mortality in young children. A randomized, community‐based trial of vitamin A supplementation in northern Sumatra demonstrated a 34 per cent reduction in mortality among pre‐school aged children who received twice yearly vitamin A supplementation. These results have stimulated renewed interest in vitamin A as a potentially important mediator of improved child survival. Cost and efficiency considerations are important in these types of trials but must be balanced with logistical constraints that are unique to these environments. A number of these issues are discussed and some general guidelines are proposed for such investigati