WASHINGTON -- The Supreme Court Monday rejected a challenge to the government's practice of barring health claims on labels of dietary supplements unless the Food and Drug Administration determines there is "significant scientific agreement" they are valid.

The court, without comment, turned away an appeal that argued the FDA regulations violate free-speech rights.A 1990 federal law, the Nutrition Labeling and Education Act, gives the FDA authority over health claims by dietary supplement products such as medicinal herbs and vitamins sold over the counter.

The agency has since issued regulations imposing significant scientific agreement as the standard for deciding whether asserted health claims are valid. Anyone may petition the FDA to authorize a health claim on a dietary supplement's label, and the agency must respond within a certain period, although a final rule can be put off for up to 18 months.

The Nutritional Health Alliance, a group of manufacturers, retailers and consumers of dietary supplements sued over the FDA regulations along with a health food store, New Nutrisserie. They contended that the labeling restriction amounts to an unlawful prior restraint of truthful commercial speech.

A federal judge in New York and the 2nd U.S. Circuit Court of Appeals ruled against the challengers.

"Given the need to protect consumers before any harm occurs, we conclude that the . . . prior restraint is sufficiently narrowly tailored" to be deemed constitutional, the appeals court ruled. "It grants a limited, but reasonable, time within which the FDA can evaluate the evidence in support of the labeling claims."

Justice Department lawyers defended the regulations' constitutionality and urged the court to reject the appeal. They also contended that the appeal is premature because the challengers have not asked the FDA to authorize any particular health claim.

The appeal did mention, however, that a claim of Vitamin E aiding the prevention of heart attacks is currently banned from dietary supplement labels "even though the claim is supported by several reputable research studies published in recent years."