Meta-Analysis of Zinc Deficiency and Its Influence Factors in Children Under 14-year-old in China

Research Article

J Fam Med. 2021; 8(5): 1257.

Meta-Analysis of Zinc Deficiency and Its Influence Factors in Children Under 14-year-old in China

Cai-Jin Y1, Jing-Ying S1 and Gang-Xi L1,2,3*

¹Department of Pediatrics, The First Affiliated Hospital of Xiamen University, The School of Clinical Medicine, Fujian Medical University, Xiamen, China

²Pediatric Key Laboratory of Xiamen, Xiamen, China

³Institute of Pediatrics, School of Medicine, Xiamen University, Xiamen, China

*Corresponding author: Lin Gang-Xi, Department of Pediatrics, The First Affiliated Hospital of Xiamen University, The School of Clinical Medicine, Fujian Medical University, Xiamen, China; Pediatric Key Laboratory of Xiamen, Xiamen, China; Institute of Pediatrics, School of Medicine, Xiamen University, Xiamen 361003, China

Received: April 13, 2021; Accepted: June 07, 2021; Published: June 14, 2021


Background: In recent years, zinc deficiency in children has attracted global attention. There are some differences in zinc deficiency in different countries and regions. However, there are few multi-center and large-sample studies on zinc deficiency in children in mainland China.

Objective: To evaluate the status of zinc deficiency and its influence factors in children under 14-year-old in mainland China, and to provide evidence-based evidence for the strategy of prevention and treatment of zinc deficiency in children.

Methods: PubMed, Embase, CNKI and other databases were searched about the cross-sectional survey literature on zinc deficiency and its influencing factors of under 14-year-old children in mainland China from 2005 to 2021. Stata 14.0 statistical software was used for Meta-analysis. Two independent reviewers identified eligible studies.

Results: We identified 55 studies with 292,877 healthy children and adolescents in the Meta-analysis. The overall zinc deficiency rate was 27.0% (95% CI 22.8%-31.3%). From coastal areas of China showed that the zinc deficiency rate was 21.7% (95% CI 16.2%-27.1%) as 29.6% (95% CI 24.9%- 34.4%) from inland area of China. The zinc deficiency rate in the male group was greater than in the female group, and the difference was statistically significant [OR=1.052, 95% CI (1.019, 1.087), p=0.002]. The zinc deficiency rate in infant group was higher than that in toddler group [OR=1.38, 95% CI (1.16, 1.64), p=0.000], preschool group [OR=1.475, 95% CI (1.163, 1.870), p=0.001], and school-age group [OR=1.746, 95% CI (1.257, 2.425), p=0.001], with statistical significance. There was no significant difference in zinc deficiency rate between the toddler group and the preschool group [OR=1.059, 95% CI (0.918, 1.222), p=0.429], the toddler group and the school-age group [OR=1.136, 95% CI (0.848, 1.523), p=0.394], and the preschool group and the school-age group [OR=0.986, 95% CI (0.754, 1.291), p=0.919]. There was no statistically significant difference in zinc deficiency rate between the groups of well-educated and the poor-educated dietary provider. (OR=1.095, 95% CI (0.867, 1.383), p=0.446), and no statistical significance in zinc deficiency rate between urban group and rural group [OR=1.152, 95% CI (0.810, 1.637), p=0.432].

Conclusions: At present, zinc deficiency in children and adolescents in mainland China is still serious, especially in infants. The zinc deficiency rate in male children was more serious than that of female children. The zinc deficiency rate of children in inland areas was higher than that in coastal areas. Factors such as different educational level of food providers and different areas from urban or rural were not the major influencing factors of zinc deficiency.

Keywords: Zinc; Zinc deficiency; Factors; Children; Meta-Analysis


Zinc is an essential micronutrient distributed throughout the body, which is involved in a variety of metabolic processes in the body. Zinc deficiency will affect a variety of body functions, including growth and development, immune function, reproductive function and neurobehavioral development, which will bring serious harm to the health of the body. In 1963, Prasad et al. [1] reported on cases of adolescent hypogonadism and dwarfism caused by zinc deficiency [2]. Thus, uncovering the important impact of zinc deficiency on human health for the first time. In 1974, Moynahan [3] described that Acrodermatitis Enteropathica (AE) is associated with severe zinc deficiency, which is an autosomal recessive genetic disease related to zinc metabolism defects, further confirming zinc Importance to human health. It is reported that approximately 116,000 child death in 2011 was related to zinc deficiency, mainly due to the prevalence and severity of infectious diseases such as diarrhea [4]. Walker et al. [5] showed that the prevalence of zinc deficiency is more serious in three regions of the world (Africa, Asia and Latin America). There are different in the status of zinc deficiency in different countries. At present, there are few multi-center studies on zinc deficiency in China. The main purpose of this study is to conduct systematic reviews and meta-analysis by collecting relevant studies to explore the overall zinc deficiency status of children aged 0-14 years in mainland China in the past 15 years and some related influencing factors, in order to provide evidence-based basis and data support for the comprehensive prevention and treatment of zinc deficiency in children in China. The research results are reported as following.


Literature and search strategy

Search Chinese and English databases such as PubMed, Embase, Cochrane Library, Web of Science, China Biomedical Literature Database (CBM) and other Chinese and English databases until February 8, 2021. Search terms are "Zinc", "Zinc deficiency", "Zinc status", "Micronutrient deficiencies", "Micronutrient status", "Micronutrient deficiency", "China/Chinese", and "Child/Children". The search is based on a combination of subject terms and free words. And incorporate unpublished documents including dissertations, conference reports and other unpublished documents through manual retrieval and literature retrospective methods. The search is carried out independently by two reviewers, and when there is a disagreement, through consultation or a third reviewer joins in the analysis and discussion and reaches a consensus.

Inclusion and exclusion criteria

Inclusion criteria: 1) The subjects of the study were healthy children and adolescents aged 0-14 years in mainland China; 2) The outcome of the study is the plasma (serum) zinc level, and the testing equipment is not limited; 3) The types of studies include published and unrestricted A publicly published cross-sectional study on zinc levels and zinc deficiency in children; 4) The study languages are limited to Chinese and English.

Exclusion criteria: 1) The subject is in the period of acute infection and inflammation, such as fever, acute diarrhea and other diseases; 2) The outcome indicator of the study is not plasma (or serum) zinc, such as hair zinc, nail zinc and other detection methods; 3) The research sample size is less than 1000 cases, and the research time is earlier than 2005; 4) The literature for which the research data cannot be extracted; 5) The literature of systematic reviews or reviews, case reports, etc.

Data extraction and quality evaluation

Data extraction was conducted after literature screening, including the first author, publication year, research area, research sample size, zinc level and zinc deficiency rate, and related influencing factors. According to the cross-sectional study quality evaluation checklist recommended by the Agency for Healthcare Research Quality (AHRQ) [6], two researchers independently evaluated the quality of the final included studies. When there is a disagreement, discuss with the third researcher and reach an agreement. The evaluation list includes 11 items. For each item, the answer is "yes", "no" or "do not know". The total score is 11 points, of which the answer to "yes" is 1 point, and the answer to "no" or "do not know" The score is 0. The higher the total score, the better the quality of the research. 0 to 3 are classified as low-quality studies, 4 to 7 are classified as mediumquality studies, and 8 to 11 are classified as high-quality studies.

Statistical analysis

Stata14.0 software (version 11) was used for statistical analysis. Q test and I2 value were used to quantitatively evaluate the heterogeneity among the included studies. If there is no significant heterogeneity among the included studies or the heterogeneity is small (P≥0.10 and/ or I2 value ≤50%), the fixed effects model is used for Meta-analysis; if the heterogeneity is large [P<0.10 and (or) I2 value >50%], then use subgroup analysis, Meta regression or one-by-one elimination of sensitivity analysis to further analyze the source of heterogeneity. If there is still heterogeneity after treatment, then use random effects model for Meta-analysis, the analysis result is P<0.05 indicating that the difference is statistically significant. The outcome indicators of zinc deficiency rate were expressed by odds ratio (OR value) and its 95% confidence intervals (CI); the funnel chart method was used and the Egger test was used to quantitatively identify publication bias.


Literature search results

Preliminary search was used to obtain 5835 documents, Endnote document management software was used to eliminate duplicate documents, and 278 documents were obtained by browsing document titles and abstracts to enter the full-text reading screening, and finally 55 documents [7-61] were included in the Meta-analysis and evaluation of this article. The sample size was 292,877 cases. The literature screening process is shown in Figure 1, and the basic information of the included literature is shown in Table 1.