Imdad A, Bhutta ZA. 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. BMC Public Health 2011; 11 (Suppl 3): S22.
- The association of zinc deficiency and growth retardation and hypogonadism is well established from animal and human studies demonstrating that zinc plays a critical role in cellular growth, cellular differentiation and metabolism (1, 2)
Zinc Supplementation on Linear Growth
- Positive effect of zinc supplementation on linear growth (weighed mean difference: 0.13; 95% CI 0.04-0.21) – 36 studies
- Subgroup analysis from studies that reported actual increase in length (cm) showed that a dose of 10 mg zinc/day for 24 weeks led to a net gain of 0.37 (+0.25) cm – 15 studies (moderate quality of evidence)
Zinc Supplementation (with Iron) on Linear Growth
- Subgroup analysis, excluding those data sets where zinc was supplemented in combination with iron, showed a more pronounced effect (weighed mean difference 0.19; 95% CI 0.08-0.30) – 34 studies
- Subgroup analysis, where zinc was given in combination with iron, showed a negative trend (weighed mean difference -0.10; 95% CI -0.21-0.01)
- These analyses strongly suggest that the addition of iron decreases the positive effect of zinc supplementation linear growth through potential interference with absorption or bio-availability.
- Preventive zinc supplementation in a dose of 10mg/day for 24 weeks in children < 5 years of age leads to a net gain of 0.37 (+0.25) cm in zinc supplemented group compared to control in developing countries.
References from Imdad Paper Cited Here
- Moynahan EJ. Letter: Acrodermatitis enteropathica: a lethal inherited human zinc-deficiency disorder. Lancet. 1974; 2(7877):399–400.
- Prasad AS. Discovery of human zinc deficiency and studies in an experimental human model. Am J Clin Nutr. 1991; 53(2):403–412.