Scientists have known for nearly sixty years that zinc is an essential nutrient. Without it, children's growth slows and adults' cognition falters. Researchers recently gave the mineral's effect on children a closer look--this time in China, where zinc deficiency is common.

They rounded up 372 children, six to nine years old, from elementary schools in three low-income districts and divided them into treatment groups. Group one received 20 mg zinc/day; group two, 20 mg zinc with a multivitamin; group three, the multivitamin alone. Teachers dispensed the vitamins six days a week for ten weeks. Researchers collected blood and hair samples (to measure changes in zinc concentrations) both before and after supplementation, assessed growth (based on the change in length of the lower leg), and conducted neuropsychological tests. The tests measured fine and gross motor skills, eye-hand coordination, attention span, visual perception, memory, concept formation and abstract reasoning.

Growth increased significantly in the children taking a multivitamin, but results were most dramatic in children who received both zinc and multivitamins. Zinc given alone produced the smallest effect. The researchers concluded that the children were probably deficient in several nutrients needed for growth.

In terms of neuropsychological function, children performed better after treatments one (zinc) and two (zinc + multivitamin) than after treatment three (multivitamin). These findings confirm the necessity of zinc for children's growth and show, for the first time, that zinc is important for their proper neuropsychological function as well.
--Am J of Clin Nutr, 65: 1803-9, June 1997