The U. S. Food and Drug Administration have issued a warning letter to the Coca-Cola Co to say that their product Diet Coke Plus is "misbranded." Coca-Cola Co's claims that its Diet Coke Plus is fortified with vitamins and minerals does not meet FDA's standards and the agency "does not consider it appropriate to fortify snack foods such as carbonated beverages."

Diet Coke Plus was launched by Coca Cola in the United States in April 2007 as a low calorie option to the regular drinks in the Coca Cola stable. The company marketed the product as "a good source of vitamins B3, B6, and B12, and the minerals zinc and magnesium."

The FDA letter also states that the product's label does not include the additional amounts of nutrients that are included in the "plus" product as per the agency's requirements.

Scott Williamson, a Coca-Cola North America spokesman said, "This does not involve any health or safety issues, and we believe the label on Diet Coke Plus complies with FDA's policies and regulations." He added that Coca Cola will provide a detailed response to the FDA in early January.

The letter, dated Dec. 10, 2008, is posted on the FDA's web site and the company has 15 days to outline plans to correct the violation. Dozens of warning letters are issued by the FDA each year and while most get resolved without further issues the FDA can levy fines or even seize products if deemed necessary.