WASHINGTON — The Food and Drug Administration is publishing a final rule that prohibits certain nutrient content claims for foods that contain omega-3 fatty acids, the agency said April 25.

The rule prohibits statements on the labels of food products, including dietary supplements, claiming the products are “high” in two kinds of omega-3 fatty acids: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Synonyms such as “rich in” and “excellent source of” also are prohibited.

In regard to similar claims for alpha-linolenic acid (ALA), another omega-3 fatty acid, the F.D.A. said it will take no regulatory action at this time on one set of nutrient content claims, but it will prohibit another set of nutrient content claims.

The F.D.A. had issued a proposed rule in the Federal Register on Nov. 27, 2007. The final rule, scheduled to be published April 28 in the Federal Register, is effective Jan. 1, 2016.

The final rules said that under the Federal Food, Drug and Cosmetic Act, nutrient content claims such as “high in” are allowed only for nutrients for which the claim refers has been set. The F.D.A. has not established nutrient levels that serve as the basis for nutrient content claims for DHA, EPA or ALA.

The F.D.A. said a notification of ALA nutrient content claims submitted by Martek Biosciences Corp. in 2005 will be allowed to remain on the market (Royal DSM nv completed its acquisition of Martek in 2011). For a “high” claim, a product must have 320 mg or more of ALA per reference amounts customarily consumed (RACC). For a “good source” claim, a product must have 160 mg or more of ALA per RACC. For a “more” claim, a product must have 160 mg or more of ALA per RACC than an appropriate reference food.

Another notification for ALA, DHA and EPA came to the F.D.A. in 2004 from Alaska General Seafoods, Ocean Beauty Seafoods, Inc. and Trans-Ocean Products, Inc. The F.D.A. prohibited the nutrient content claims from the three seafood processors.

In regard to ALA, the F.D.A. said the seafood processors used a population-weighted approach as opposed to a population-coverage approach used by Martek.

“In most situations, the reference value that results from the population-coverage approach will be higher than the reference value that results from the population-weighted approach,” the F.D.A. said. “Thus, by using the latter method, a company can in effect hold itself to a lower standard when making claims such as “good source” or “high.”