Dietary supplement safety should be treated as a "relative concept" under the Institute of Medicine's proposed scheme for a systematic approach to evaluating supplements, CHPA Senior VP-Director of Science & Technology William Soller, PhD, suggested July 24.

Commenting on an IoM committee's Proposed Framework for Evaluating the Safety of Dietary Supplements released that day, Soller said the Consumer Healthcare Products Association is "generally supportive" of the committee's work.

But he drew attention to issues CHPA asserts merit continued attention and refinement, including the very concept of safety.

Under the three-step evaluation system developed by the panel, safety monographs would assess current data for supplement ingredients selected for review (see ¹ Also see "Three-Step Supplement Safety Review Model Proposed by IoM" - Pink Sheet, 29 July, 2002.). The monographs could be drafted in-house by FDA or contracted out to consultants.

The monographs would contain "recommendations and conclusions about the safety" of ingredients, according to the IoM committee's report, Soller noted during the question-and-comment period at the committee's briefing. "What constitutes the definition of 'safety' here?" he asked.

"Safety is not an absolute concept, it's a relative concept," he said. Experience with other FDA processes, including OTC drug review, have shown that definition of terms can significantly affect the outcome of a review process, he added. Soller also questioned whether the monographs would reach specific recommendations for FDA action or report only scientific conclusions.

While the committee's report refers to the monographs as containing safety "recommendations," it also describes them as "collating" information, with FDA deciding on whether to take action based on the "totality" of scientific information obtained.

Addressing Soller's comments, IoM Committee Chair and UC/Davis nutrition professor Barbara Schneeman, PhD, said: "One of the issues that the committee has had to come to grips with is that the process that we have been asked to engage in is not about declaring things to be 'safe.'" She continued: "What we were being asked for from FDA is how to prioritize the different types of data they have, to make decisions about where there are risks that something could cause harm."

Also suggesting the need for specificity and nuance in identifying safety issues, Council for Responsible Nutrition VP-Nutritional & Regulatory Science John Hathcock, PhD, commented: "It's more interesting ultimately to identify the level at which some adverse event may occur than to decide whether an adverse event might occur."

There are "plenty of examples to justify that kind of viewpoint," he added. To illustrate, he said, "I don't think anyone doubts that vitamin A can be toxic. The real question is at what level does this occur." Hathcock expressed hope that this "perspective can be pulled into the monograph format."

"We did take this into consideration," committee member Elizabeth Jeffery, PhD, University of Illinois-Urbana, responded, agreeing that addressing issues such as "dose and duration are extremely important."

The proposed framework focuses solely on supplement safety, per FDA's request. This focus is "appropriate since dietary supplements are regulated as foods that must be safe, rather than as drugs requiring a risk-benefit analysis." The panel notes also that FDA has the burden of proof in evaluating supplements because, like foods, they are assumed safe unless the agency shows evidence otherwise.

The framework centers on supplement ingredients, rather than finished products, which may vary substantially in their safety profiles due to differing amounts of the ingredients, presence of other substances or combination with other ingredients. Jeffery pointed out that an ingredient monograph would have wider applicability than one based on individual products.

Previous public comment had suggested that multi-ingredient products have particular priority for safety evaluations (² Also see "Multi-Ingredient Supplements Warrant Priority Safety Review - Whitehall Rep" - Pink Sheet, 15 October, 2001., p. 4). After the briefing, Schneeman said that combination ingredient products are an important issue, but FDA must first set up a workable process to review single ingredients before taking up such products.

The IoM panel will hear further comment on its proposed framework at a planned September public forum. It has pushed back the anticipated completion of its final report to FDA to March 2003.

IoM Supplement Framework Should Reflect “Relative” Safety – CHPA

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