Role of micronutrients namely vitamin A, zinc and folate, as adjunct therapy of illness episodes in children in developing countries have been discussed in the light of health policy. Apart from a selective review, attempts have been made to statistically combine results of several studies to address policy issues. In children, vitamin A supplementation during illness has (a) a profound effect in reducing mortality in measles, (b) possibly a significant effect in reducing persistent diarrhea episodes in children with acute diarrhea, and (c) no benefit in pneumonia.
Use of large dose vitamin A is recommended during measles episodes but not in non-measles pneumonia. Its use in acute diarrhea is debatable but recommended in persistent diarrhea and in severe malnutrition as a component of a micronutrient mixture. Large dose vitamin A supplementation should be used with caution in young infants as there are unresolved concerns about its safety particularly, bulging fontanelle observed in infants when co-administered at immunization. In children, zinc supplementation during illness, (a) had a marked effect in reducing prolonged episodes and a modest effect on episode duration in acute diarrhea, (b) resulted in reduced rate of treatment failure and death in persistent diarrhea, (c) had no effect in measles and non-measles pneumonia, and (d) probably had a detrimental effect of increasing death rate when a large dose was used in severely malnourished children. The desirability of routine zinc supplementation therapy of undernourished children with acute diarrhea should be assessed further. Concerning policy, zinc supplementation as a component of a micronutrient mixture is recommended in the rehabilitation of severely malnourished children and in persistent diarrhea. However, recommendation for its routine use in all cases of acute diarrhea in children needs additional studies on effectiveness, cost, operations and safety. In two randomized controlled trials folate has been evaluated in acute and persistent diarrhea and found to have no beneficial effect. Folate is not recommended as adjunct therapy of diarrhea. Role of folate in preventing severe disease and/or death deserves further evaluation.