AUTHOR=Hu Jun , Sang Jiajia , Hao Feng , Liu Li 

TITLE=Association between vitamin A and asthma: A meta-analysis with trial sequential analysis

JOURNAL=Frontiers in Pharmacology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2023.1100002

DOI=10.3389/fphar.2023.1100002

ISSN=1663-9812

ABSTRACT=<p><bold>Objective:</bold> To explore the association between vitamin A (vit A) status and risk of asthma.</p><p><bold>Methods:</bold> PubMed, Web of Science, Embase and the Cochrane Library were electronically searched to identify related studies that reported the association between vit A status and asthma. All databases were searched from inception to November 2022. Two reviewers independently screened literature, extracted data, and assessed risk bias of included studies. Meta-analysis was performed on R software Version 4.1.2 and STATA Version 12.0.</p><p><bold>Results:</bold> A total of 19 observational studies were included. A pooled analysis showed that the serum vit A concentrations in patients with asthma was lower than that in healthy controls (standard mean difference (SMD)= −2.479, 95% confidence interval (CI): −3.719, −.239, 95% prediction interval (PI): −7.510, 2.552), and relatively higher vit A intake in pregnancy was associated with an increased risk of asthma at age 7 years (risk ratio (RR)= 1.181, 95% CI: 1.048, 1.331). No significant correlation was observed between serum vit A levels or vit A intake and the risk of asthma.</p><p><bold>Conclusion:</bold> Our meta-analysis confirms that serum vit A levels are lower in patients with asthma than in healthy controls. Relatively higher vit A intake during pregnancy is associated with an increased risk of asthma at age 7 years. There is no significant correlation between vit A intake and asthma risk in children, nor between serum vit A levels and asthma risk. The effect of vit A may depend on age or developmental stage, diet and genetics. Therefore, further studies are needed to explore the association of vit A and asthma.</p><p><bold>Systematic Review Registration:</bold><ext-link ext-link-type="uri" xlink:href="https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021222541" xmlns:xlink="http://www.w3.org/1999/xlink">https://www.crd.york.ac.uk/prospero/CRD42022358930</ext-link>, identifier CRD42022358930</p>