The Effect of Vitamin D Supplementation on Breast Density Changes: A Clinical Trial Study

ABSTRACT

The aim of this study was to determine the effect of supplementation with 50,000 IU/monthly vitamin D for 1 yr on breast density in Iranian women. Methods: This double-blind, placebo-controlled, single center clinical trial was conducted among 400 women aged 40 yr and older. Participants were allocated to 2 groups. Group 1 received vitamin D (Cholecalciferol) 50,000 IU in tablet form, monthly, for 1 yr. Group 2 received vitamin E 400 IU in tablet form, monthly, for the same period of time. Participants had follow-up clinic visits every 6 mo and received an annual mammogram. Results: Final data were evaluated based on 216 and 194 women in the vitamin D and control groups. The mean decrease in mammographic density was −5.01%(95% CI, −9.9% to −0.01%) and −2.34 %(95% CI, −6.84% to −2.15%) in the vitamin D and control groups, respectively. There was no significant association between vitamin D consumption and breast density after 1 yr (OR = 0.7, 95% CI, 0.46 to 1.06; P = 0.1).Similar results were observed when multivariate model of logistic regression analysis was performed. Conclusions: This study showed that monthly consumption of 50,000 IU of vitamin D supplementation for 1 yr did not affect breast density.

Declaration of Interest

No potential conflicts of interest were disclosed.

Acknowledgment

We would like to thank the research development center of Arash women's hospital for their contributions in the process of preparing this article.

Additional information

Funding

This study was funded by Tehran University of Medical Sciences and Health Services no. (89-02-39-10530).