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Review
, 11 Suppl 3 (Suppl 3), S22

Effect of Preventive Zinc Supplementation on Linear Growth in Children Under 5 Years of Age in Developing Countries: A Meta-Analysis of Studies for Input to the Lives Saved Tool

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Review

Effect of Preventive Zinc Supplementation on Linear Growth in Children Under 5 Years of Age in Developing Countries: A Meta-Analysis of Studies for Input to the Lives Saved Tool

Aamer Imdad et al. BMC Public Health.

Abstract

Introduction: Zinc plays an important role in cellular growth, cellular differentiation and metabolism. The results of previous meta-analyses evaluating effect of zinc supplementation on linear growth are inconsistent. We have updated and evaluated the available evidence according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria and tried to explain the difference in results of the previous reviews.

Methods: A literature search was done on PubMed, Cochrane Library, IZiNCG database and WHO regional data bases using different terms for zinc and linear growth (height). Data were abstracted in a standardized form. Data were analyzed in two ways i.e. weighted mean difference (effect size) and pooled mean difference for absolute increment in length in centimeters. Random effect models were used for these pooled estimates. We have given our recommendations for effectiveness of zinc supplementation in the form of absolute increment in length (cm) in zinc supplemented group compared to control for input to Live Saves Tool (LiST).

Results: There were thirty six studies assessing the effect of zinc supplementation on linear growth in children < 5 years from developing countries. In eleven of these studies, zinc was given in combination with other micronutrients (iron, vitamin A, etc). The final effect size after pooling all the data sets (zinc ± iron etc) showed a significant positive effect of zinc supplementation on linear growth [Effect size: 0.13 (95% CI 0.04, 0.21), random model] in the developing countries. A subgroup analysis by excluding those data sets where zinc was supplemented in combination with iron showed a more pronounced effect of zinc supplementation on linear growth [Weighed mean difference 0.19 (95 % CI 0.08, 0.30), random model]. A subgroup analysis from studies that reported actual increase in length (cm) showed that a dose of 10 mg zinc/day for duration of 24 weeks led to a net a gain of 0.37 (± 0.25) cm in zinc supplemented group compared to placebo. This estimate is recommended for inclusion in Lives Saved Tool (LiST) model.

Conclusions: Zinc supplementation has a significant positive effect on linear growth, especially when administered alone, and should be included in national strategies to reduce stunting in children < 5 years of age in developing countries.

Figures

Figure 1
Figure 1
Synthesis of study identification in review of the effects of zinc supplementation on growth.
Figure 2
Figure 2
Effect sizes for height gain in zinc intervention trials among children less than 5 years of age in developing countries. Final estimate from 48 data sets of 36 studies. (Includes data sets with zinc + iron)[]
Figure 3
Figure 3
Effect sizes for height gain in zinc intervention trials among children less than 5 years of age in developing countries. Final estimate from 39 data sets of 34 studies. (Includes data sets with zinc supplementation alone)
Figure 4
Figure 4
Main gain in height (in cm) in zinc supplemented (alone) group compared to control. Data from 28 studies in the form 32 data sets irrespective of dose and duration of supplementation.
Figure 5
Figure 5
Forest plot for mean gain in height (cm) after zinc supplementation alone in children less than 5 years of age: Subgroup analysis according to different dosages
Figure 6
Figure 6
Mean gain in height (cm) after 10 mg zinc supplementation alone for 24 weeks in children < 5 years of age in developing countries

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References

    1. Moynahan EJ. Letter: Acrodermatitis enteropathica: a lethal inherited human zinc-deficiency disorder. Lancet. 1974;2(7877):399–400. doi: 10.1016/S0140-6736(74)91772-3. - DOI - PubMed
    1. Prasad AS. Discovery of human zinc deficiency and studies in an experimental human model. Am J Clin Nutr. 1991;53(2):403–412. - PubMed
    1. Brown KH, Peerson JM, Baker SK, Hess SY. Preventive zinc supplementation among infants, preschoolers, and older prepubertal children. Food Nutr Bull. 2009;30(1 Suppl):S12–40. - PubMed
    1. Brown KH, Peerson JM, Rivera J, Allen LH. Effect of supplemental zinc on the growth and serum zinc concentrations of prepubertal children: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2002;75(6):1062–1071. - PubMed
    1. Ramakrishnan U, Nguyen P, Martorell R. Effects of micronutrients on growth of children under 5 y of age: meta-analyses of single and multiple nutrient interventions. Am J Clin Nutr. 2009;89(1):191–203. doi: 10.3945/ajcn.2008.26862. - DOI - PubMed
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