B O S T O N, Sept. 19, 2000 -- People who take calcium supplements usually hope to build strong bones, not heavy metals.
But that’s exactly what may be happening, according to a team of researchers who found traces of lead in several calcium supplements currently on grocery and pharmacy shelves.
Nutritional experts fear this discovery might unnecessarily scare the 5 percent of the population who currently take the mineral. But by highlighting the issue for consumers, investigators say they hope to motivate all the calcium supplement manufactures to reduce lead levels to undetectable amounts.
Earlier research detected the lead in calcium tablets and activist groups had pushed to regulate those levels. But the lead levels persist, the new study finds.
A Third of Pills Contained Lead Researchers at the University of Florida, Gainesville, are reporting that eight of the 22 calcium products they tested — including popular national brands such as Caltrate 600 — contained lead, the toxic metal that can lead to anemia, high blood pressure, brain and kidney damage in adults and developmental damage in children.
The study, published in the current issue of the Journal of the American Medical Association, found several of the products contained as much as 3 micrograms per 1,500 milligrams of calcium, approaching the Food and Drug Administration’s recommended safety cutoff of 6 micrograms per day. This is of special concern for those who may take calcium in high amounts, such as those on dialysis who need extra calcium and women battling osteoporosis.
“This should not be a reason to stop taking calcium supplements,” says Dr. Edward A. Ross, lead author of the paper and head of the renal disease program at the University of Florida’s School of Medicine. “But it should be a reason to look for better ones.”
But Dr. Robert Heaney, a professor at Creighton University in Omaha, Neb., who consults for some calcium supplement manufacturers, argues in an accompanying editorial that all the products tested were well below the FDA’s cutoff limit.
“In truth, this is not bad, but good news,” he writes. “The calcium sources available today are generally very safe.”
Lead, Lead Everywhere Lead is present in the air, soil and water around us, as well as foods such as berries, raisins and salads, forcing us to take in small levels every day, Heaney explains.
So how does lead end up in the calcium tablets? Many calcium products that tout themselves as “natural” come from oyster shells mined from mineral beds in the ocean that naturally contain lead.
Thanks to regulations eliminating lead from the gas we pump, the paint we use and the cans and bottles we eat from, the FDA reports that ingested lead levels have dropped significantly in this country, from 30 micrograms a day in the early ’80s to fewer than 5 micrograms a day in the mid ’90s. Corresponding levels of lead in our blood have dropped as well.
But for some, such as poverty-stricken children exposed to lead dust and paint in older homes, lead exposure still is a risk.
It is only because lead has been dramatically reduced from our environment that it is worth worrying about these small amounts in nutritional supplements, Ross contends.
But Heaney points out that because calcium itself happens to be a mineral that blocks the absorption of lead, it basically counteracts any possible lead contamination in the body.
“A backlash against calcium supplements — evoked by a lead scare — would unquestionably do far more harm than continued ingestion of supplements,” Heaney writes.
Dr. David Heber, head of the UCLA center for human nutrition, agrees. “This article was a little bit alarmist,” he cautions. “The health benefits of calcium supplementation far outweigh any dangers of lead ingestion.”
Findings Mimic Earlier Results The presence of lead in calcium supplements had been made public decades ago. A widely reported study published in the American Journal of Public Health in 1993 found a quarter of the 70 calcium supplements tested exceeded the daily levels the FDA set for young children.
In 1997, the Natural Resources Defense Council, a New York City-based environmental group, petitioned the FDA to lower acceptable lead levels in supplements to 0.5 micrograms a day and filed a lawsuit against calcium makers. The lawsuit was settled by the manufacturers and resulted in those standards being enacted only in California. There was no change in the FDA’s national regulations.
Michael Bolger, chief of the division of risk assessment at the FDA, says a tenfold margin of safety is built into the agency’s current guidelines, so no change was warranted. The levels of lead detected in these supplements are so low, he adds, it should concern only those dialysis patients requiring the high doses.
And experts at the Council for Responsible Nutrition, a Washington, D.C.-based trade group representing supplement manufacturers, who opposed the change in FDA regulations, say the study shows the industry has responded to this issue by improving refinement techniques and mining sites.
“The products out there now are even cleaner and purer than before,” says Annette Dickinson, vice president of scientific and regulatory affairs for the trade group. “There’s no basis for concerns at levels this low.”
Shoot to Be Lead-Free
But Ross responds that there is no “safe” level of lead. If you can avoid lead, you ought to,” he says.
And if manufacturers can now produce lead-free products, consumers have a right to them, he says. “There are many products on the market already without detectable quantities,” he says. “It should not be guesswork.”
For those who want to their calcium pills “unleaded,” Ross suggests looking to buy calcium supplements that are already specifically labeled as “lead-free.”
“How much lead,” he asks, “are you willing to get from your supplement?”