Safety of dietary supplements use among patients with cancer: A systematic review

Dietary supplements (DS) are commonly taken by patients with cancer, but safety of DS use remains unclear. A systematic literature search was conducted using PubMed, ClinicalTrials.gov, International Pharmaceutical Abstracts and Alt HealthWatch databases from inception through October 12, 2018. Included studies were limited to clinical trials including patients with cancer, DS products as interventions, evaluation of safety endpoints of DS use, and published in English. Sixty-five studies were included to evaluate 20 different DS among patients with 12 types of cancer. Botanical DS (n = 13), vitamins (n = 8), and probiotics/synbiotics (n = 7) were the top 3 types of DS evaluated in these trials. Majority of studied DS appeared safe. Among 19 trials including patients with cancer undergoing chemotherapy, most (n = 18) of studied DS (e.g., vitamins, botanical, omega-3 fatty acid) were found to be safe. Evaluation of DS use and its safety should be regularly incorporated in clinical trials among patients with cancer.