UPDATE 2-US FDA warns over Diet Coke Plus nutrition claims

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By Susan Heavey

WASHINGTON, Dec 23 (Reuters) - Coca-Cola Co's (KO.N) claims that Diet Coke Plus includes a variety of vitamins and minerals violate U.S. policy against marketing soda and other snack foods as more nutritious, or "fortified," health regulators said in a warning letter to the company.

"The FDA does not consider it appropriate to fortify snack foods such as carbonated beverages," the U.S. Food and Drug Administration agency told the beverage giant in a letter dated Dec. 10 and made public on Tuesday.

It was not clear if the FDA was seeking to remove the product from the U.S. market, and a spokesman for the FDA had no immediately comment.

"You should take prompt action to correct the violations," the FDA wrote. The agency could take further action, including seizing products, seeking injunctions and levying fines.

Manufacturers routinely try to boost the value of their foods and beverages by adding extra nutrients.

The FDA allows such claims when foods or beverages contain at least 10 percent of the recommended daily allowance of a vitamin or mineral. But the claims cannot apply to soda or certain foods, including candy, its regulations state.

Representatives for Coca-Cola defended the calorie-free product's claims.