Caltrate Absorption Comparison With Citracal Needs Clarification – NAD

Promotional claims implying the absorption of Wyeth's Caltrate calcium supplement is equivalent to Mission Pharmacal's Citracal should be modified "to more clearly reflect the conditions under which bioequivalence was demonstrated," the National Advertising Division concludes following a recent inquiry.

The ad monitoring division of the Council of Better Business Bureaus agrees that supporting data referenced by Wyeth provides a "reasonable basis in support of its claims" that the calcium from calcium carbonate, which is used in Caltrate, has equivalent absorbability to calcium citrate (Citracal).

However, the group concludes the data could not support a parity claim citing the finished products because they were not directly compared in the research.

Mission Pharmacal took issue with the parity claim as presented in a now-discontinued product brochure and a physician-directed newsletter. The brochure originally claimed "The calcium in Caltrate absorbed as well as the calcium in Citracal when taken with food."

However, the brochure was discontinued prior to resolution of the challenge and the claim was revised to state: "Equivalent to calcium citrate when taken with food."

The newsletter to physicians claimed that "the calcium absorption of the two most commonly available salts, calcium carbonate (e.g., Caltrate) and calcium citrate is equivalent."

The primary study cited by Wyeth in support of its claims was conducted by Robert Heaney, Creighton University, et al. and appeared in the Journal of the American College of Nutrition in 2001.

According to Mission, "Wyeth, in support of its claims, relied on testing of calcium compounds rather than the commercially available competing products," noting that the study used GlaxoSmithKline's Os-Cal and not Caltrate to represent calcium carbonate.

"NAD has established that the actual product advertised must be used in a study for substantiation of a claim," Mission said, pointing to a previous case in which NAD rejected the use of a study that "did not speak to the actual commercially available competing products."

In response, Wyeth noted that "a head-to-head study was not necessarily the only potential source of such support" and contended that it "presented a reasonable basis for presuming that there were no material differences between the absorbability of Caltrate and Os-Cal."

NAD acknowledged that the company "provided a scientific and logical explanation why it may be expected that Caltrate's absorption should be equivalent to Os-Cal."

However, NAD also noted that "there are numerous factors that may impact the disintegration, dissolution, and absorption of calcium."

As a result, NAD determined that "it is unclear whether consumers and/or physicians reasonably interpret the claim to be a comparison involving the Caltrate product or whether the comparison is limited to the salt, calcium carbonate."

The watchdog group also suggested that details of the scientific findings would be beneficial to physicians who read the newsletter where the claim appeared.

Mission pointed to the fact that participants were supplemented with a vitamin D product ( Calderol ) as a second flaw in the 2001 Heaney study.

According to Mission, "the advertising for Caltrate fails to disclose to consumers that vitamin D supplementation was required to obtain equivalency of calcium absorption and, consequently, the product parity claim is misleading."

However, NAD did not agree that vitamin D supplementation undermines the conclusions regarding absorption of the two forms of calcium.

Calcium absorption parity claims have been an ongoing point of contention between Mission, Wyeth and GlaxoSmithKline and have come before NAD in the past. In 2002, both Wyeth and GSK challenged Mission's ad claim that Citracal was better absorbed than calcium carbonate. NAD concluded that the claims should be discontinued in two separate cases (¹ (Also see "Citracal Quantified Calcium Absorption Superiority Claims Unproven – NAD" - Pink Sheet, 5 Aug, 2002.), p. 7 and ² 'The Tan Sheet' May 19, 2003, In Brief).