Researchers Troubled by Calcium Supplement Lead Levels

GAINESVILLE, Fla.-- The amount of lead found in some calcium products may lead to "avoidable" health concerns, according to a study published in the Sept. 20 issue of the Journal of the American Medical Association (JAMA) (284:1425-1429, 2000).

Twenty-three calcium products were analyzed: 21 formulations of nonprescription calcium carbonate (seven natural [i.e. from oyster shell] and 14 refined), one brand of prescription-only calcium acetate and one non-calcium synthetic phosphate binder. The researchers set the absolute dietary limit for lead content at 6 mcg of lead per 800 to 1,500 mg/d of calcium. Researchers set the absolute limit for lead in dietary supplements at 1 mcg/d.

Four out of seven natural calcium products contained 1 mcg of lead per 800 mg/d and 1 to 2 mcg of lead per 1,500 mg/d. High calcium doses treating osteoporosis and kidney function yielded higher amounts of lead [between 3 and 20 mcg/d]. No lead was detected in the calcium acetate or polymer products.

In an editorial published in the same issue of JAMA, Dr. Robert Heaney rebutted the study's results. Heaney, who is affiliated with Creighton University and works as a consultant and scientist for many U.S. calcium suppliers, wrote that calcium actually blocks lead absorption, contraindicating the harmful effects of lead. Calcium barricades intestinal lead absorption and reduces access to endogenous lead deposits. Heaney conceded that calcium supplements that have been tested for lead should be labeled.

Albion Laboratories, which manufactures calcium amino acid chelates and other complex calcium forms, is one company that makes sure its calcium has been tested before and after production. "It is up to the producer of the calcium ingredients and the marketers of the calcium products to insure that the lead level is acceptable for their consumers," said Max Motyka, director of the human products division at Albion. "It is not required by law [that calcium lead levels be regulated], so if the customer is concerned, they need to check with their calcium product's company [in regards to lead content]."

For a copy of this study, visit http://jama.ama-assn.org/