"Almost everybody's diet falls short somewhere," said Dickinson.
Dickinson also agrees that some unscrupulous manufacturers have given the entire supplement industry a black eye. One egregious example, she says, occurred with the efforts to stop the sale of supplements containing ephedra, a compound linked to several deaths nationwide.
"The controversy over ephedra dragged on years longer than it should have," Dickinson said. "The most we can do is petition the [enforcement] agencies to take action."
In 2004, sales of the substance were banned by the Food and Drug Administration, following their review of ephedra's safety and effectiveness from clinical studies and numerous reports of the compound's adverse effects.
But the length of time it took before ephedra was removed from store shelves -- and the deaths that occurred before it was banned -- highlight the weaknesses in the regulatory environment under which the supplement industry operates.
The Dietary Supplement Health and Education Act, signed into law in 1994, determined that supplements should be regulated not like drugs, but like foods. By making this determination, according to today's IOM report, supplement manufacturers were exempt under DSHEA from conducting any safety or efficacy testing.
To many industry critics, the net effect of DSHEA has been to limit the FDA's role to a reactive, post-market role. Only after the FDA determines that a substance, when used as recommended, presents a risk to consumers can the agency remove it from the market.
And because manufacturers are not required to report adverse effects from a substance, the burden for proving that a substance is harmful falls to the FDA.
But Dickinson and others believe the fallout from the ephedra controversy has made the regulatory framework for supplement manufacturers more robust.
"For the first six or eight years after DSHEA was passed, the FDA didn't do much to implement the law," Dickinson concedes. But then came the ephedra controversy.
"It used to be called the 'body rule,' " says ConsumerLab's Cooperman, referring to the number of deaths that were needed to prompt an investigation from the agency. "You needed to have a lot of adverse effects before you could go looking for a cause. ... But ephedra has emboldened the FDA to act more quickly."
Now, Dickinson says, "the FDA is taking strong enforcement action to fully implement DSHEA" -- something she says her group welcomes. She believes criticisms that the supplement industry is unregulated are entirely unfair.
But some critics are not mollified by these assurances.
"As I see it, the main effect of the DSHEA has been to allow supplement companies to run rampant and make claims that are not substantiated," said Dr. Kevin Scott Ferentz, residency director in the Department of Family Medicine at the University of Maryland School of Medicine in Baltimore.
"They sell products that do not contain what they are supposed to. They do not have efficacy data, safety data, quality control data or anything that any pharmaceutical product in America must have," he said. "There are few, if any, supplements that have a data base that is sufficient to recommend their use."
In almost all cases, experts advise consumers to approach dietary supplements with caution -- and with reliable information.
"Consult with your physician," said Brooks. "And use reliable sources for information. We have people come in with all sorts of Internet ads."
"Consumers need to inform themselves about what they're using," said Dickinson. "The primary risk is from their own ignorance."
This is especially true for patients taking prescription drugs. "If they're taking other medications, they should check with their primary care physician just in case there are contraindications," said Cooperman.
And Ferentz notes that no dietary supplement should be considered a panacea. "People want to think there is a magic pill out there for everything," he said. "They assume that because something is a 'natural supplement' that it has to be safe and effective. Nothing could be further from the truth."