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World J Methodol. May 20, 2022; 12(3): 164-178
Published online May 20, 2022. doi: 10.5662/wjm.v12.i3.164
Participant attrition and perinatal outcomes in prenatal vitamin D-supplemented gestational diabetes mellitus patients in Asia: A meta-analysis
Sumanta Saha, Sujata Saha
Sumanta Saha, Department of Community Medicine, R. G. Kar Medical College, Kolkata 700004, West Bengal, India
Sujata Saha, Department of Mathematics, Mankar College, Mankar 713144, West Bengal, India
Author contributions: Sumanta Saha conceptualized, designed, analyzed, and drafted the first and final versions of the manuscript; all authors contributed to the study selection, data abstraction, and risk of bias assessment of this manuscript; all authors have read and approved the final manuscript.
Conflict-of-interest statement: The authors declare there are no conflicts of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2020 statement Checklist, and the manuscript was prepared and revised according to the PRISMA 2020 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Sumanta Saha, DNB, MBBS, Doctor, Teacher, Department of Community Medicine, R. G. Kar Medical College, Kolkata, 700004 West Bengal India, Kolkata 700004, West Bengal, India.
Received: December 1, 2021
Peer-review started: December 1, 2021
First decision: January 12, 2022
Revised: January 20, 2022
Accepted: March 26, 2022
Article in press: March 26, 2022
Published online: May 20, 2022
Research background

The role of vitamin D in gestational diabetes mellitus (GDM) is not established. Several randomized controlled trials (RCT) have tested it.

Research motivation

The burden and risk of participant attrition from vitamin D receiving treatment arm/s of these trials are unclear. Also, the effect of vitamin D and its co-supplemented forms and other supplements on the mother’s glycemic control and perinatal outcomes remains unclear.

Research objectives

This study aimed to address these issues.

Research methods

Eligible clinical trials were retrieved by searching the PubMed, Embase, and Scopus databases. The burden and risk of participant attrition got determined by random-effect prevalence and pairwise meta-analysis, respectively. The effect of different nutritional supplements on the perinatal outcomes got estimated by fixed-effect network meta-analysis. All analysis ensued in Stata statistical software (v16).

Research results

The database search produced 13 RCTs conducted in Iran and China. The participant attrition from vitamin D treated arms was 6% (95% confidence interval [CI]: 0.03, 0.10), and this risk did not vary from its non-recipient arms. The cesarean section risk decreased with the combined supplementation of vitamin D and calcium [risk ratio (RR): 0.37; 95%CI: 0.18, 0.74]. The vitamin D alone and its co-supplemented forms with calcium and omega-3 fatty acids decreased the risk of newborn- hyperbilirubinemia or hospitalization. The probiotics co-supplemented form of vitamin D decreased newborn hyperbilirubinemia risk (RR: 0.28; 95%CI: 0.09, 0.91). The fasting plasma glucose levels didn’t vary across the compared interventions.

Research conclusions

This study suggests that vitamin D supplementation is a relatively well-tolerated intervention in GDM patients resulting in relatively low participant attrition from RCTs testing it. Also, this study suggests that some nutritional supplements can be beneficial in reducing perinatal outcomes.

Research perspectives

Given the low burden of participant attrition from the vitamin-supplemented arms of RCTs, future trialists may find the conduct of RCTs with a larger sample size reasonable to produce rigorous results.