Kessler's log, supplemental.

THE OPENING ACT OF A WASHINGTON power grab always makes for fascinating, if now increasingly common, spectacle. But Food and Drug Administration Commissioner David Kessler's war on vitamins, minerals, and other dietary supplements is a real standout.

Kessler knows how to put on a show in the committee hearing rooms of Capitol Hill, where in the last few months he has been promoting his plan to impose sweeping new regulations on supplements. His assistants are even making the rounds of newspaper editorial rooms to press the FDA's case.

Kessler adamantly denies that the FDA will in any way limit access to or doses of vitamins and other supplements. He accuses critics of scaremongering. Yet the FDA's advance notice of proposed rule making in the June 18 Federal Register, the government's regulatory bible, indicates otherwise. Indeed, one gets a sense of cognitive dissonance listening to Kessler and reading the official record, which says that the agency would like to regulate amino acids as drugs, remove a number of herbs from the market, and set safety limits on vitamin and mineral potencies.

Matching Kessler's public statements against the scientific evidence can easily give the impression that it is the FDA chief who is doing the scaremongering. Perhaps the extreme positions outlined in the Federal Register notice were mere trial balloons. Nevertheless, Kessler has made it clear that the FDA wants to suppress consumer information about nutrients by forbidding manufacturers from making any health claims without prior FDA approval. Such a position is dubious at best, given the breath-taking new findings about the critical role nutrients play in preventing the chronic diseases that kill modern Americans--cancer, heart disease, diabetes, osteoperosis--as well as cataracts, infectious diseases, neural-tube birth defects, and other conditions. The potential human cost of restricting such information is huge.

When his time comes to testify at a subcommittee hearing, Kessler strides to the witness table and a bevy of aides springs into action. They set up large colored charts illustrating supplement dangers and heap on floors and tables big clear plastic bags filled with supplement bottles, presumably dangerous, fraudulent, or both.

His voice rising in indignation, Kessler insists that, contrary to what the $4-billion dietary supplement industry says, he is not out to deprive anyone of vitamins. (The $4-billion figure implies an unspoken connection between industry revenue and public danger.) Charges that the FDA is out to restrict consumer access or limit potencies, he insists, are "absolutely false." But if someone wants to sell such products, he adds, the FDA has to make sure that there is "no problem with safety," that "the potencies are reasonable," and that any health claims are supported by "significant scientific agreement."

AS IT TURNS OUT, THOSE ARE MAJOR RESTRICTIONS. Kessler believes that the dietary supplement market is "awash in unsubstantiated claims," that manufacturers are bilking consumers by selling "snake oil" cures for everything from baldness to AIDS. False claims, he says, not only cost unwitting consumers millions but so mislead them that they neglect proper medical treatment.

The solution, Kessler insists, is prior FDA approval of any health claim. But prior approval requires considerably more than the reasonable-sounding plea that health claims be "scientifically valid." It amounts to subjecting vitamin health claims to something like the extensive clinical trials that the FDA now requires for drug approvals, a cumbersome process that takes over a decade and costs some $230 million. For a patentable pharmaceutical. FDA's nod might be worth the investment. For inexpensive vitamins and minerals long in the public domain, such a process presents an insuperable barrier.

"There is a downside, and that's cost." Kessler concedes to one skeptical congressman. But righteous indignation rises again to dispel such worries. "The answer is not to throw up our hands," he adds. "The choice is whether to hold |supplements~ to a scientific standard or not. Somebody's going to have to fund the research to do that."

So far, the FDA has rejected every nutrient/disease claim except the link between calcium and prevention of osteoperosis, and approval for that claim came nearly a decade after the National Institutes of Health confirmed the connection. Two years after the Centers for Disease Control said that folic-acid supplements reduce the risk of neural-tube detects, the FDA still has not authorized that claim, although it says it will. Meanwhile, some 2,500 such birth defects occur each year. The FDA continues to reject claims about dietary fiber and cardiovascular disease and cancer, zinc and immune function in the elderly, omega-3 fatty acids and heart disease, and the antioxidant vitamins A, C, and E and cancer.

In just the last five years, massive new evidence has poured forth on the role nutrients play in preventing heart disease and cancer. Highly credible studies are indicating astonishing rates of disease reduction--as much as 40 percent in heart disease with vitamin E supplementation. If a pharmaceutical were discovered that reduced the risk of heart disease by 40 percent with no toxicity and cost pennies a day, it would no doubt be hailed as a miracle drug.

In a revealing moment, Kessler acknowledges to a subcommittee that nutrition science is "evolving." But he adds that his grandmother taught him to eat a well-balanced diet, and that is "certainly the best approach. It was good back then and it's still good today." Jeffrey Blumberg, a nutrition professor at Tufts University in Boston, says such a statement "tends to deny the last 40 years of research in nutrition science," implying that "Kessler's grandmother represented the state of the art 40 years ago and today as well, and that's wrong."

After Kessler's appearance (and the departure of most reporters), Gladys Block, a nutrition scientist at the University of California at Berkeley, testifies that the FDA's drug model simply does not fit nutrition. "The search for a 'magic bullet,' for the right nutrient, comes from a medical model of the right drug to kill a microbe and cure a disease," Block says. "Public health, health promotion, demands a different model. There is no one right nutrient."

WHILE KESSLER CATEGORICALLY DENIES that the FDA will limit "megadose" vitamin supplements, the agency made clear the direction it favors in its Federal Register notice. There is a "need for a comprehensive science-based evaluation of evaluation of the potential toxicity of vitamins and minerals at various intake levels," the agency says, and a "need to establish the levels of intake" that are safe. The notice cites FDA task force recommendations for a new "dietary supplement limit," or DSL, "for each vitamin and essential mineral." The agency elaborates at length on how a large number of supplements on the market exceed the government's existing RDAs, or Recommended Daily Allowances. These are levels that nutrition scientists say are the bare minimum necessary to gradually reverse such acute nutrient-deficiency syndromes as scurvy.

The FDA has tried to limit vitamin and mineral doses before. It was stopped only when Congress intervened in 1976 with the Proxmire Amendment, which continues to prohibit the agency from doing so. Yet if the FDA establishes so-called DSLs, the result could well be a de-facto potency limit for manufacturers afraid to market anything more than what is deemed safe by the FDA.

Kessler's real trump card, however, is a contaminated batch of the amino acid L-tryptophan, linked to 38 deaths and 1,500 injuries in the United States. For Kessler, L-tryptophan is the new thalidomide, the 1950s-era drug that caused hideous birth defects in Europe and led to a huge expansion of FDA power (even though the FDA's regulatory authority was strong enough at the time that thalidomide was never approved for sale in the United States).

Kessler repeatedly cites the L-tryptophan incident, despite convincing evidence that the contaminant was solely to blame. The agency now goes so far as to say that the essential amino acid itself could be the culprit. Blumberg, the Tufts nutrition professor, himself no devotee of amino acids, says the FDA position is "very hard to understand. I have not seen any evidence, none, zero, and the FDA hasn't put any forth. They've just made this speculation." Indeed, the FDA continues to allow L-tryptophan in infant formulas and hospital intravenous feeding--presumably because the ingestion of this suspected "toxin" is essential to maintaining health.

At each congressional hearing on supplements, several unfortunate victims of the L-tryptophan incident testify to the members, who cannot fail to be moved by their tragic stories (each of them linked only to the contaminated batch). As Connecticut Democrat Rosa DeLauro leans forward to nod in sympathy, as committee chairmen John Dingell and Henry Waxman warn darkly of the dangers of unregulated snake oils, as the weather vane Washington Post runs its piece on how Utah Republican Orrin Hatch, the FDA's chief opponent in the vitamin wars, is a paid-off stooge for the vitamin industry, one has to admire David Kessler's masterful performance.

Contributing Editor Carolyn Lochhead is Washington correspondent of the San Francisco Chronicle.