Effects of iron and zinc fortified milk supplementation on working memory of underweight poor-urban school children: A randomized double blind controlled trial

Abstract

Background Undernutrition associated micronutrient
deficiencies in children are still prevalent in most developing
countries. Iron and zinc deficiencies are the most common
micronutrient deficiency globally, which significantly contribute
deficits in cognitive function. Fortification with iron and zinc has
proven successfully in reducing certain cognitive impairments
like memory.
Objective To determine the effects of milk fortified with iron and
zinc on memory of underweight poor-urban schoolchildren.
Methods A double blind randomized controlled trial was
conducted on 218 underweight poor-urban schoolchildren aged
7-9 years old; 113 children were supplemented twice daily with
27 gram of milk fortified with iron pyrophosphate (12.15 mg) and
zinc sulfate (4.4 mg) for three months, 105 children served as
controls. Anthropometry measured including bodyweight, height,
sitting height and middle upper arm circumference. Memory was
measured using digit span backward test in Wechsler Intelligence
Scales III. Statistical analyses were performed with SPSS for
Windows, version 11.0.
Results Baseline data of digit span backward score in iron and
zinc group was 2.4 (SD 1.2), and control group was 3.0 (SD 1.8).
After intervention, mean digit span backward score in iron and
zinc group was 3 .1 (SD 1.2) and in control group 3.0 (SD 1.3).
There was no improvement digit span backward score in control
group after intervention, compared with 0.7 point improvement
in iron and zinc group (P=0.009).
Conclusion Milk fortified with iron and zinc improves working
memory of underweight poor-urban schoolchildren.