Zinc supplementation boosts immune system in children, review finds Zinc supplements reduce diarrhea and other infections in malnourished children, and may prevent death, according to a new study published in The Cochrane Library . The study is the first Cochrane systematic review to focus on zinc as a means to prevent childhood death, including deaths caused by diarrhea, one of the biggest killers of under-fives. Zinc is a micronutrient with important roles in growth and in the immune, nervous and reproductive systems. The human body cannot make it, so it has to come from our diet. It is estimated that more than 1 in 6 people globally are deficient in zinc and that around 1 in every 58 deaths in children under five is related to zinc deficiency. Zinc deficiency is common in Southeast Asia, sub-Saharan Africa and parts of Latin America. The authors were interested in whether zinc supplements could reduce childhood death and disease, and help support growth. They ...