Page 108 - EJMO-9-3

Eurasian Journal of Medicine

and Oncology

ORIGINAL RESEARCH ARTICLE
The association between Vitamin D and breast

cancer: A two-sample Mendelian randomization
study

Yang Xiao 1 , Mei Yin 2 , and Xingyi Song *
2
1 Department of Breast and Thyroid Surgery, Peking University Shenzhen Hospital, Shenzhen,
Guangdong, China
2 Department of Humanities and Social Sciences, Harbin Medical University, Harbin, Heilongjiang,
China

Abstract

Introduction: Breast cancer, as a significant threat to women’s health globally, has
a complex pathogenesis. Vitamin D, a steroid hormone with diverse physiological
functions, has garnered increasing attention in breast cancer research. Numerous
studies have been conducted to elucidate the relationship between Vitamin D and
breast cancer, yet no definitive conclusions have been reached. Objective: Hence, in
this study, we conducted a two-sample Mendelian randomization (MR) analysis to
investigate the association between Vitamin D and breast cancer.
Methods: Genetic variants associated with Vitamin D levels and breast cancer data
were obtained from the genome-wide association study database and version R11 of
*Corresponding author: the FinnGen study dataset, respectively. The inverse variance-weighted (IVW) method
Xingyi Song served as the primary analytical approach, supplemented by various sensitivity
(xy19460809@163.com) analyses. Horizontal pleiotropy was tested using MR-Egger and MR-Pleiotropy
Citation: Xiao Y, Yin M, Song X. RESidual Sum and Outlier methods, while sensitivity analysis was conducted using
The association between Vitamin the leave-one-out method to assess the reliability of the results.
D and breast cancer: A two-sample
Mendelian randomization study. Results: Based on instrumental variable assumptions, 111 single nucleotide
Eurasian J Med Oncol. polymorphisms were suitable for subsequent analyses after matching the results.
2025;9(3):100-109. The MR analysis demonstrated no evidence of a causal relationship between Vitamin
doi: 10.36922/EJMO025130064 D and breast cancer. The IVW method yielded a non-significant association (p=0.968;
Received: March 24, 2025 odds ratio = 1.002, 95% confidence interval: 0.896 – 1.119), and the other methods
Revised: April 5, 2025 pointed out the same direction of effect, and the subsequent pleiotropic analysis and
sensitivity analysis confirmed the accuracy of the results.
Accepted: April 16, 2025 Conclusion: At the genetic level, no causal relationship between Vitamin D and
Published online: May 14, 2025 breast cancer was found; thus, our findings do not support a clinically significant role
Copyright: © 2025 Author(s). of Vitamin D supplementation in breast cancer risk reduction
This is an Open-Access article
distributed under the terms of the
Creative Commons Attribution Keywords: Vitamin D; Breast cancer; Mendelian randomization
License, permitting distribution,
and reproduction in any medium,
provided the original work is
properly cited. 1. Introduction
Publisher’s Note: AccScience Breast cancer, as one of the most common cancers, is one of the leading causes of death
Publishing remains neutral with for women worldwide. Over the past 20 years, breast cancer rates have continued to
1
regard to jurisdictional claims in 2
published maps and institutional rise in most countries. In 2022, there were approximately 2.309 million new cases of
affiliations. breast cancer globally, ranking second among all cancers, with a corresponding crude

Volume 9 Issue 3 (2025) 100 doi: 10.36922/EJMO025130064