Because of our intervention design, we could not attribute the
decrease in morbidity to individual micronutrients in the
multiple-micronutrient–fortified seasoning powder group.
Because zinc has a key role in enhancing immune function [36]
and potential antiviral properties [37], the zinc fortification
was most likely responsible for the additional decreased
morbidity reported in the present study compared with the
vitamin A–only and vitamin A plus iron groups.