Coexistence of micronutrient malnutrition: implication for nutrition policy and programs in Asia.

Micronutrients (MN) share common metabolic pathways, or work in complementarity. Missing or having too much of one micronutrient may tip the balance, resulting in manifested deficiencies of one or more micronutrients. Coexistence of micronutrient deficiencies have been reported from developing countries. This raises the concern of the commonly implemented single micronutrient supplementation. Efficacy of high dose of multiple micronutrient supplementation has been tested but results are mixed. This may be dependent on which outcomes were measured. It is possible that interaction is more likely with high dose of MN supplementation. Shifting from single to multiple micronutrient supplementation will still encounter the same challenges to program effectiveness. Food-based strategy is a promising public nutrition measure. However, it requires a holistic environment to be effective. More evidence on efficacy and/or effectiveness of food-based interventions is urgently needed, to establish policy and program options to deal with coexistence of multiple micronutrient deficiencies. Interactions among micronutrients are recognized, and should be taken into account for designing appropriate intervention program.