Assuring Quality of Dietary Supplements for Cancer Patients: An Integrative Formulary Systems Approach.

Context: The quality of dietary supplements is highly variable and, therefore, may pose unique risks to cancer patients, who increasingly use these products. Although they are highly regulated, the US Food and Drug Administration (FDA) has reported extensive noncompliance with current Good Manufacturing Practices (cGMPs), which further heightens concerns.

Objective: The study intended to investigate the dietary supplements quality practices of current and prospective suppliers of supplements.

Design: Thirteen manufacturers, marketing 19 dietary supplement brands, were selected for inclusion, and 9 participated.

Setting: This study took place at and was supported by the Cancer Treatment Centers of America (Boca Raton, FL, USA).

Outcome Measures: To ensure patients' safety, the research team established a dietary supplement formulary committee at the Cancer Treatment Centers of America. A proprietary survey tool was used to measure clinically critical quality markers and compliance with FDA regulations. Information was obtained from suppliers via nondisclosure agreements. Manufacturing documents were audited and compared with responses to the survey. The FDA's audit reports were obtained by request under the Freedom of Information Act. Several site audits were conducted, and third-party analytical testing was performed as needed.

Results: Although all companies claimed full compliance with cGMPs as of the survey's date, (1) 3 had received warning letters from the FDA for GMP violations, (2) 2 had recalled a product within the preceding 5 y, (3) 4 had reported products that failed independent testing for potency and purity, (4) 1 did not have product specifications, (5) 1 was found by the FDA to have inadequate testing, (6) 1 was found to have a lack of sufficient controls throughout the supply chain to guard against microbial contamination, and (7) 2 had confirmed melamine contamination or lack of melamine testing for protein powders.

Conclusions: These findings confirm the concern of variable dietary supplement quality and describe a rational process others can use to assess products' quality and ensure patients' safety. Although the current study focused on practitioners' branded products used in an oncology setting, the results are relevant to the use of all dietary supplements in both oncological and nononcological settings.