scholarly journals Excessive Vitamin A Supplementation Increased the Incidence of Acute Respiratory Tract Infections: A Systematic Review and Meta-Analysis

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4251
Author(s):  
Yihan Zhang ◽  
Yifei Lu ◽  
Shaokang Wang ◽  
Ligang Yang ◽  
Hui Xia ◽  
...  

(1) Background: vitamin A deficiency (VAD) is highly prevalent in children living in poor conditions. It has been suggested that vitamin A supplementation (VAS) may reduce the risk of acute respiratory tract infections (ARTI). Our study provides updates on the effects of oral VAS (alone) in children on ARTI and further explores the effect on interesting subgroups. (2) Methods: eight databases were systematically searched from their inception until 5 July 2021. The assessments of inclusion criteria, extraction of data, and data synthesis were carried out independently by two reviewers. (3) Results: a total of 26 randomized trials involving 50,944 participants fulfilled the inclusion criteria. There was no significant association of VAS with the incidence of ARTI compared with the placebo (RR 1.03, 95% CI 0.92 to 1.15). Subgroup analyses showed that VAS higher than WHO recommendations increased the incidence of ARTI by 13% (RR 1.13, 95% CI 1.07 to 1.20), and in the high-dose intervention group, the incidence rate among well-nourished children rose by 66% (RR 1.66, 95% CI 1.30 to 2.11). (4) Conclusions: no more beneficial effects were seen with VAS in children in the prevention or recovery of acute respiratory infections. Excessive VAS may increase the incidence of ARTI in children with normal nutritional status.

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaoyan Wang ◽  
Xingming Li ◽  
Chunhua Jin ◽  
Xinyuan Bai ◽  
Xinran Qi ◽  
...  

To evaluate the association between serum vitamin A levels and the prevalence of recurrent respiratory tract infections (RRTIs) in children and adolescents and to provide evidence that would help decrease the prevalence of respiratory tract infections (RTIs) in children. This cross-sectional study included 8034 children and adolescents in Beijing aged 6 months to 17 years. RRTI and RTI symptoms were diagnosed according to the Clinical Concept and Management of Recurrent Respiratory Tract Infections in Children. Multivariate logistic regression models were used to evaluate the association between serum vitamin A levels and RRTIs after adjusting for potential confounders. Among the included children, 721 (8.97%) were diagnosed with vitamin A deficiency, whereas 3,073 (38.25%) were diagnosed with subclinical vitamin A deficiency. Only 28.8% (208/721) of children with vitamin A deficiency and 53.1% (1,631/3,073) of children with subclinical vitamin A deficiency had no RRTI and RTI symptoms, respectively. Compared with children with normal vitamin A levels, those with vitamin A deficiency and subclinical vitamin A deficiency had a greater risk for RRTIs, with an odds ratio (OR) of 6.924 [95% confidence interval (CI): 5.433–8.824] and 2.140 (95% CI: 1.825–2.510), respectively]. Vitamin A levels were also positively associated with RTI symptoms, with those having vitamin A deficiency and subclinical vitamin A deficiency showing an OR of 1.126 (95% CI: 0.773–1.640) and 1.216 (95% CI: 1.036–1.427), respectively. The present cross-sectional study found that low serum vitamin A levels were significantly associated with RRTI or RTI prevalence in children and adolescents.


2007 ◽  
Vol 97 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Kurt Z. Long ◽  
Jorge L. Rosado ◽  
Herbert L. DuPont ◽  
Ellen Hertzmark ◽  
Jose Ignacio Santos

Previous clinical vitamin A trials have found no consistent effect on diarrhoeal disease and respiratory tract infection. These inconsistent results may be due to the distinct effects vitamin A supplementation has among children stratified by factors related to socio-economic status, nutritional status and season. We evaluated the effect of supplementation on the overall incidence of diarrhoeal disease and respiratory tract infections and on the incidence among children stratified by these factors. A total of 188 children, aged 6–15 months, from periurban, marginalized communities of Mexico City were assigned to receive vitamin A ( < 12 months of age, 20 000 IU retinol; ≥ 12 months, 45 000 IU retinol) or a placebo every 2 months, and were followed for up to 15 months. Project personnel visited households twice a week to determine the onset and duration of diarrhoeal disease and respiratory tract infections. Vitamin A supplementation had no significant effect on risk of overall diarrhoeal disease but reduced mild watery diarrhoea (incidence rate ratio (RR) 0·69; 95 % CI 0·50, 0·93) and cough with fever (RR 0·69; 95 % CI 0·48, 0·98). Vitamin A supplementation decreased diarrhoeal disease during the summer (RR 0·74; 95 % CI 0·57, 0·94), among non-stunted children (RR 0·69; 95 % CI 0·52, 0·93) and among children from households with better socio-economic measures. Heterogeneity in the response to vitamin A supplementation may reflect heterogeneity in the aetiology and epidemiology of diarrhoeal disease and respiratory tract infections and the impact that supplementation has on the immune response.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Rafik Dey ◽  
Melanie A. Folkins ◽  
Nicholas J. Ashbolt

AbstractHuman respiratory syncytial virus (RSV) is a major cause of acute respiratory tract infections in children and immunocompromised adults worldwide. Here we report that amoebae-release respirable-sized vesicles containing high concentrations of infectious RSV that persisted for the duration of the experiment. Given the ubiquity of amoebae in moist environments, our results suggest that extracellular amoebal-vesicles could contribute to the environmental persistence of respiratory viruses, including potential resistance to disinfection processes and thereby offering novel pathways for viral dissemination and transmission.


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