» Articles » PMID: 35565906

Reconsidering the Tolerable Upper Levels of Zinc Intake Among Infants and Young Children: A Systematic Review of the Available Evidence

Overview
Journal Nutrients
Date 2022 May 14
PMID 35565906
Authors
Affiliations
Soon will be listed here.
Abstract

Safe upper levels (UL) of zinc intake for children were established based on either (1) limited data from just one study among children or (2) extrapolations from studies in adults. Resulting ULs are less than amounts of zinc consumed by children in many studies that reported benefits of zinc interventions, and usual dietary zinc intakes often exceed the UL, with no apparent adverse effects. Therefore, existing ULs may be too low. We conducted a systematic bibliographic review of studies among preadolescent children, in which (1) additional zinc was provided vs. no additional zinc provided, and (2) the effect of zinc on serum or plasma copper, ceruloplasmin, ferritin, transferrin receptor, lipids, or hemoglobin or erythrocyte super-oxide dismutase were assessed. We extracted data from 44 relevant studies with 141 comparisons. Meta-analyses found no significant overall effect of providing additional zinc, except for a significant negative effect on ferritin ( = 0.001), albeit not consistent in relation to the zinc dose. Interpretation is complicated by the significant heterogeneity of results and uncertainties regarding the physiological and clinical significance of outcomes. Current zinc ULs should be reassessed and potentially revised using data now available for preadolescent children and considering challenges regarding interpretation of results.

Citing Articles

Current and potential contributions of large-scale food fortification to meeting micronutrient requirements in Senegal: a modelling study using household food consumption data.

Adams K, Engle-Stone R, Wibberley B, Tsang B, Tarini A, Beye M BMJ Public Health. 2025; 2(2):e001221.

PMID: 39822945 PMC: 11737596. DOI: 10.1136/bmjph-2024-001221.


Tracing Zinc's Role in Preterm Infants' Health: A Narrative Review.

Consales A, Agostoni C, Cazzola R, Ottria R, Gianni M Adv Nutr. 2024; 15(12):100295.

PMID: 39675840 PMC: 11705620. DOI: 10.1016/j.advnut.2024.100295.


Estimating food consumption, micronutrient intake and the contribution of large-scale food fortification to micronutrient adequacy in Tanzania.

Goto R, Mlambo L, Segovia De La Revilla L, Swai A, Mshida H, Amos A Public Health Nutr. 2024; 27(1):e230.

PMID: 39526477 PMC: 11645117. DOI: 10.1017/S136898002400199X.


Mandatory large-scale food fortification programmes can reduce the estimated prevalence of inadequate zinc intake by up to 50% globally.

Wessells K, Manger M, Tsang B, Brown K, McDonald C Nat Food. 2024; 5(7):625-637.

PMID: 38898330 PMC: 11272573. DOI: 10.1038/s43016-024-00997-w.


Potential Complementary Effect of Zinc and on Gut Health and Immunity: A Narrative Review.

Wong-Chew R, Nguyen T, Rogacion J, Herve M, Pouteau E Nutrients. 2024; 16(6).

PMID: 38542798 PMC: 10976165. DOI: 10.3390/nu16060887.


References
1.
Alarcon K, Kolsteren P, Prada A, Chian A, Velarde R, Pecho I . Effects of separate delivery of zinc or zinc and vitamin A on hemoglobin response, growth, and diarrhea in young Peruvian children receiving iron therapy for anemia. Am J Clin Nutr. 2004; 80(5):1276-82. DOI: 10.1093/ajcn/80.5.1276. View

2.
Wuehler S, Sempertegui F, Brown K . Dose-response trial of prophylactic zinc supplements, with or without copper, in young Ecuadorian children at risk of zinc deficiency. Am J Clin Nutr. 2008; 87(3):723-33. DOI: 10.1093/ajcn/87.3.723. View

3.
Sian L, Hambidge K, WESTCOTT J, MILLER L, Fennessey P . Influence of a meal and incremental doses of zinc on changes in zinc absorption. Am J Clin Nutr. 1993; 58(4):533-6. DOI: 10.1093/ajcn/58.4.533. View

4.
Hess S, Abbeddou S, Jimenez E, Some J, Vosti S, Ouedraogo Z . Small-quantity lipid-based nutrient supplements, regardless of their zinc content, increase growth and reduce the prevalence of stunting and wasting in young burkinabe children: a cluster-randomized trial. PLoS One. 2015; 10(3):e0122242. PMC: 4376671. DOI: 10.1371/journal.pone.0122242. View

5.
Veenemans J, Milligan P, Prentice A, Schouten L, Inja N, van der Heijden A . Effect of supplementation with zinc and other micronutrients on malaria in Tanzanian children: a randomised trial. PLoS Med. 2011; 8(11):e1001125. PMC: 3222646. DOI: 10.1371/journal.pmed.1001125. View