Kellogg Co. says it will pull immunity claims from its Rice Krispies and Cocoa Krispies cereal boxes amid the public's growing concern about swine flu.

Kellogg began adding extra antioxidants to its cereal last year, which it says help support the immune system. The company began advertising the change with large labels on cereal boxes that read in bold letters: "Now helps support your child's immunity."

But the food maker said Wednesday that given the public attention to swine flu, it has decided to phase out the message from its packages.

Kellogg, based in Battle Creek, Mich., said it has heard very little concern from consumers about the claim, but is responding to concerns in the media about the timing of this front-of-the-box claim and the swine flu outbreak.

Company spokeswoman Susanne Norwitz said swine flu was not a concern when the product was in development, and was intended to respond to consumer desire for improved nutrition.

Kellogg said it will take several months to phase out the packaging but it will continue to offer the increased levels of certain vitamins in the cereal.

Food makers have been facing increasing scrutiny for the labels that they put on their products, which have increased in number and scope in recent years.

General Mills was chided by the FDA for claiming Cheerios could lower cholesterol, saying only FDA-approved drugs are allowed to make such claims.

But the Food and Drug Administration said manufacturers are responsible for truth of claims such as Kellogg's.

The FDA monitors the claims, but something like "supports immunity" is considered a structure or function claim -- which describes the role of a nutrient or ingredient and doesn't require the same scrutiny that other health claims might.

So a company can say "calcium builds strong bones" or "fiber maintains bowel regularity," but it's up to the manufacturer to ensure the accuracy and truthfulness of the claim, and they are not preapproved by the FDA.

Kellogg shares gained 79 cents to $51.90 in afternoon trading.