Os-Cal, Citracal Parity Claims Modification Recommended By NAD

GlaxoSmithKline's ad claims that its Os-Cal calcium supplement is absorbed "just as well as" Mission Pharmacal's Citracal may be misleading without "more clearly communicat[ing] the basis of the declared comparison," the National Advertising Division of the Council of Better Business Bureaus concludes in a recently released Case Report.

After reviewing clinical data submitted by GSK in support of the claims, NAD recommended the company modify its parity statements "to reflect the conditions under which bioequivalence was demonstrated." The inquiry into the Os-Cal advertising was prompted by Mission Pharmacal.

NAD determined unqualified equal absorption claims "overstated the limited scope" of a study, conducted by Robert Heaney, MD, Creighton University, et al., and published in June 2001. The study served as a primary basis for the claims.

The print advertising in question refuted the propo-sition that calcium citrate (Citracal) is a more readily absorbable form of the nutrient than calcium carbonate, which is contained in Os-Cal. "Let's set the story straight," one claim stated, "Os-Cal calcium is absorbed just as well as Citracal."

NAD expressed concern the Heaney study may not be representative of "real world" conditions, because it involved administration of prescription strength vitamin D along with the calcium supplements. The vitamin D was given to normalize levels of the nutrient in participants and create an "even playing field" between the two products, the group notes.

GSK said that, although it "disagrees with NAD's findings that because Dr. Heaney used a vitamin D supplement in his study, the results do not apply to all consumers of calcium supplements, it accepts NAD's recommendation that it modify its parity claims to clarify that Dr. Heaney's study demonstrates that the products are equally absorbable in people who are vitamin D sufficient."

NAD also expressed concern with statements that Os-Cal is the more economical choice because it is less expensive, yet equally as effective, as its competitor. The group concurred with GSK's offer to include a disclosure statement specifying what strengths of Os-Cal and Citracal are involved in the comparison.

In a network TV ad for Os-Cal that recently began airing, Olympic figure skater Peggy Fleming states "Os-Cal has the most concentrated form of calcium, so even though an Os-Cal tablet is smaller, it has about 60% more calcium than Citracal." An on-screen super notes the comparison reflects "Os-Cal 500 mg vs. Citracal 315 mg per tablet."

NAD additionally advises GSK to modify claims that Os-Cal is "recommended by more doctors" and is "clinically proven effective to help maintain bone mass in more studies."

The ad review group noted survey data provided the basis for the doctor recommendation claim. In the survey, conducted by NDC Health, internists were asked to choose which calcium supplement was preferred for their patients, for women at risk of osteoporosis and for women who are "serious about their bone health."

NAD advised the claim be changed to "more accurately reflect the wording of the survey." In response, GSK said it will "modify this claim to make it a brand preference claim rather than a 'doctor recommended' claim."

To substantiate its claim referencing "more clinical studies" for Os-Cal, GSK noted 17 studies have been conducted on the efficacy of the supplement in maintaining bone mass.

However, NAD advised that GSK "either modify the context in which these studies are referenced so as to avoid any potential implication that simply because more studies have been conducted for its product than for a competitor's, its product is superior, or limit the use of the referenced studies to a monadic context."

NAD has been involved in an ad dispute between the two calcium supplement marketers before. In a case announced in August 1998, the group concluded Mission Pharmacal's studies did not support superiority claims for Citracal (¹ (Also see "Mission Pharmacal Citracal superior calcium bioavailability claims unsupported -- NAD." - Pink Sheet, 10 Aug, 1998.), p. 4).

Citracal and Os-Cal are virtually tied in the calcium supplement market in food, drug and mass outlets, with dollar shares of 12.6% and 12.5%, respectively, in the 52 weeks ended Dec. 9, according to data from Information Resources, Inc. During the period, Citracal sales rose 6.6% while Os-Cal revenues fell 4.1%.