The effect of vitamin D supplementation on insulin-like growth factor-1: A systematic review and meta-analysis of randomized controlled trials

Fatemeh Meshkini; Shima Abdollahi; Cain C T Clark; Sepideh Soltani

doi:10.1016/j.ctim.2020.102300

The effect of vitamin D supplementation on insulin-like growth factor-1: A systematic review and meta-analysis of randomized controlled trials

Complement Ther Med. 2020 May:50:102300. doi: 10.1016/j.ctim.2020.102300. Epub 2020 Jan 7.

Authors

Fatemeh Meshkini¹, Shima Abdollahi², Cain C T Clark³, Sepideh Soltani⁴

Affiliations

¹ Department of Biochemistry, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran; Student Research Committee, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
² Department of Nutrition and Public Health, School of Public Health, North Khorasan University of Medical Sciences, Bojnurd, Iran.
³ Faculty Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, CV1 5FB, UK.
⁴ Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, 74877-94149, Iran. Electronic address: s.soltani1979@yahoo.com.

PMID: 32444034
DOI: 10.1016/j.ctim.2020.102300

Abstract

Purpose: There is equivocality regarding the interaction between vitamin D and insulin-like growth factor-1 (IGF-1). Thus, the aim of this study was to elucidate the effect of vitamin D supplementation on serum levels of IGF-1 by conducting a systematic review and meta-analysis of randomized controlled trials (RCTs).

Methods: PubMed, Scopus, and ISI Web of Science databases were searched up to May 2019 for RCTs that evaluated the effect of vitamin D supplementation on IGF-1 levels. Mean and standard deviation changes of IGF-1 in each treatment group were considered for analysis and pooled using random-effect model. Risk of bias for included studies was assessed by the Cochrane scale and the NutriGrade approach was applied to evaluate the quality of evidence.

Results: Six trials (n = 773 participants) were included in the meta-analysis. Compared with control group, vitamin D supplementation yielded no significant effect on serum level of IGF-1 (weighted mean difference [WMD] =4.66 ng/ml, 95 % CIs: -6.72 to 16.03, P = 0.42, I² = 74.8, P_{-heterogeneity} = 0.001). Additionally, no meaningful changes were observed in subgroup analyses.

Conclusion: The evidence from the limited number of published trials does not convincingly show that vitamin D supplementation elicits any clinically relevant effects on IGF-1 levels. More high-quality studies are needed to reach a consensual conclusion in this area.

Keywords: Growth factor; Insulin-Like growth Factor-1; Meta-analysis; Vitamin D.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Dietary Supplements*
Humans
Insulin-Like Growth Factor I / analysis*
Randomized Controlled Trials as Topic
Vitamin D / pharmacology*

Substances

Vitamin D
Insulin-Like Growth Factor I