The U. S. Food and Drug Administration warned Procter & Gamble Co that two of its products, Vicks DayQuil and NyQuil, with vitamin C have false and misleading labeling, in response to which the P&G said that it would work with the agency to resolve its concerns.

The FDA added that the products are misbranded since vitamin C is included in the list of ingredients which are inactive.

The FDA wrote to P&G President and Chief Executive Bob McDonald, “Because the vitamin C in these products is an active drug ingredient, it is therefore both false and misleading to state that it is an inactive ingredient in these drug products”.

The FDA spokesman Christopher Kelly said that it was not denying the agency’s letter but also told the Reuters that the warning letter was sent by mistake.

P&G advertises that DayQuil Plus Vitamin C has more than 150 percent of the recommended value of Vitamin C.

The company said, "Marketing within the FDA regulations and will work with the FDA to resolve the concern together."

P&G, while advertising for Vicks, says that the vitamin can definitely help in reducing the effects of cold.

The FDA has been given the responsibility to verify the marketing claims of the drug.