Reconsidering the Tolerable Upper Levels of Zinc Intake among Infants and Young Children: A Systematic Review of the Available Evidence.
Nutrients
; 14(9)2022 May 05.
Article
en En
| MEDLINE
| ID: mdl-35565906
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 (p = 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.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Zinc
/
Estado Nutricional
Tipo de estudio:
Systematic_reviews
Límite:
Adult
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Child
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Child, preschool
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Humans
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Infant
Idioma:
En
Revista:
Nutrients
Año:
2022
Tipo del documento:
Article
País de afiliación:
Canadá