Post-Diagnosis use of Antioxidant Vitamin Supplements and Breast Cancer Prognosis: A Systematic Review and Meta-Analysis

source extracted confidence: high 2026-04-09
#antioxidants #ascorbic-acid #breast-neoplasms #cancer-survivors #dietary-supplements

Post-Diagnosis use of Antioxidant Vitamin Supplements and Breast Cancer Prognosis: A Systematic Review and Meta-Analysis

Li et al., 2021 | Clin Breast Cancer | Meta Analysis

Citation

Li Yong, Lin Qimou, ... Li Weiwen. Post-Diagnosis use of Antioxidant Vitamin Supplements and Breast Cancer Prognosis: A Systematic Review and Meta-Analysis. Clin Breast Cancer. 2021-Dec;21(6):477-485. doi:10.1016/j.clbc.2021.09.001

Abstract

Antioxidant vitamin supplements (AVSs) are widely used among breast cancer survivors. Whether post-diagnosis use of AVSs would impair cancer survival is unclear. To assess the association between breast cancer survival and post-diagnosis AVSs use. We performed a literature search using PubMed, Cochrane Library, and Embase from their inception to October 1, 2020. Studies that investigated the association between breast cancer survival and post-diagnosis AVS use included. The AVSs included 1 or more of the following: vitamin A, C, or E. The meta-analysis included 8 studies with 17,062 patients. There was no significant difference between AVS use or not after diagnosis (HR 0.92, 95% CI 0•82-1•03) or during chemotherapy (HR 1.15, 95% CI 0.78-1.68) in overall survival (OS). Whenever during chemotherapy or after diagnosis, AVS users had a worse prognosis in the later studies. There was no significant inverse association between post-diagnosis vitamin A or E supplements use and OS. Vitamin C intake after breast cancer diagnosis was significantly associated with better OS (HR 0.84, 95% CI 0.76-0.93). Our findings suggest that post-diagnosis AVSs use would not worsen breast cancer survival, while vitamin C use after diagnosis might benefit OS. The discrepancy of survivals associated with post-diagnosis AVS use between earlier and later studies may cast doubt on the recommendation on guidelines. RCTs with large sample sizes are needed.

Key Findings

RCTs with large sample sizes are needed.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 17062
Age Range See abstract
Condition See abstract

MeSH Terms

  • Antioxidants
  • Ascorbic Acid
  • Breast Neoplasms
  • Cancer Survivors
  • Dietary Supplements
  • Female
  • Health Status
  • Humans
  • Primary Prevention
  • Vitamin A
  • Vitamin E

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: vitamin-a

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09