Vitamin a supplementation during pregnancy in shaping child growth outcomes: A meta-analysis

Abstract

Abnormal fetal growth increases risks of childhood health complications. Vitamin A supplementation (VAS) is highly accessible, but literature inconsistency regarding effects of maternal VAS on fetal and childhood growth outcomes exists, deterring pregnant women from VAS during pregnancy. This meta-analysis aimed to analyze effects of vitamin A only or vitamin A + co-intervention during pregnancy in healthy mothers (MH) or with complications (MC, night blindness and HIV positive) on perinatal growth outcomes, also assess VAS dose impacts. The Cochrane Library, PubMed, ScienceDirect, Scopus, Embase and Web of Science databases were searched from inception to July 15, 2021. We covered subgroup analyses, including VAS in MH or MC within randomized controlled trial (RCT) or observational studies (OS). Fifty-five studies were included in this meta-analysis (426,098 pregnancies). Vitamin A decreased risk of preterm birth by 9% in MH-RCT (P < 0.001), by 62% in MH-OS (P = 0.029), by 10% in MC-RCT (P = 0.089); decreased LBW by 24% in MC-RCT (P = 0.032); increased neonatal weight in MC-RCT (SMD 0.96; P = 0.051). Besides, vitamin A + co-intervention decreased risks of preterm by 18% in MH-OS (P = 0.021); LBW by 25% in MH-OS (P < 0.001); by 32% in MC-RCT (P = 0.006); decreased neonatal defects by 33% in MH-OS (P = 0.064); decreased anemia by 25% in MH-OS (P = 0.0003); increased neonatal weight in MH-OS (SMD 0.51; P = 0.014); and increased neonatal length in MH-OS (SMD 1.83; P = 0.013). Meta-regression of VAS dose with individual outcomes was not significant, and no side effects were observed for VAS doses up to 4000 mcg (RAE/d). Regardless of maternal health conditions, VAS during pregnancy can safely and effectively improve fetal development and neonatal health even in mothers without VAD.

Keywords:

• Pregnancy
• vitamin A deficiency
• supplementation
• fetal growth
• birth outcomes
• child health

Acknowledgements

Special thanks to Gengping Zhu (Department of Entomology, Washington State University), who helped us in the QGIS map development.

Authors’ contribution statement

The authors’ responsibilities were MD designed the research, contributed greatly to data interpretation, and critically revised the manuscript. GLM and YTC conducted the research, screened the references, extracted the data, analyzed the data, wrote the initial draft of the manuscript, and revised the final manuscript. XDL extracted the data, helped in data interpretation, and played critical role in revising the final manuscript. YG, JMD and MJZ contributed greatly to analyze data and revise the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

Data share statement

Data described in the manuscript, code book, and analytic code will be made available upon request pending application and approval.

Disclosure statement

All the authors declare that they have no conflicts of interest to this meta-analysis.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was funded by NIH R01 HD067449.