A survey of 324 multivitamin-mineral products by scientists from the Center for Food Safety and Applied Nutrition, US Food and Drug Administration (FDA) estimates that exposure to lead was below the provisional total tolerable intake levels (PTTI).
“These safe/tolerable levels are referred to as the provisional total tolerable intake levels (PTTI) and are 6, 15, 25, and 75 micrograms of lead per day for young children, older children, pregnant or lactating women, and adult women, respectively,” wrote the authors in the Journal of Agricultural and Food Chemistry.
“Estimates of lead exposures were below the PTTI levels for the four population groups,” they added.
The results were welcomed by the industry. John Hathcock, PhD, senior vice president, scientific and international affairs for the Council for Responsible Nutrition (CRN) complimented the researchers for their use of state-of-the-art methodology.
Daniel Fabricant, PhD, vice president, scientific and regulatory affairs at the Natural Products Association told NutraIngredients-USA.com: "Testing of finished products is something the FDA is doing more of and I believe by having the methodology out there that they are using to evaluate products is very valuable to both the industry with GMPs now being enforced, and the consumer in that there are apples to apples comparisons.”
William Mindak, John Cheng, Benjamin Canas and Michael Bolger surveyed 324 multivitamin-mineral products labeled for use by women or children. “Samples were chosen at random without respect to market share, brand or other factors,” explained the scientists.
Using microwave assisted nitric acid digestion and inductively coupled plasma mass spectrometry (ICD-MS), Mindak and co-workers estimated lead exposures for four population groups: young children (0-6 yrs), older children (7+ yrs), pregnant or lactating women, and adult women.
For the respective groups, the average lead exposures were 0.123, 0.356, 0.845, and 0.842 micrograms per day. The maximum lead exposures were 2.88, 1.78, 8.97, and 4.92 micrograms of lead per day for young children (0-6 yrs), older children (7+ yrs), pregnant or lactating women, and adult women, respectively.
“Most samples were extremely low in lead, with a median value of 0.160 mg/kg and only four samples exceeding 1 mg/kg,” wrote Mindak and co-workers.
“The mean and maximum estimates of lead exposure for all the products are below the tolerable intake levels for the at risk population groups of children, pregnant women, and adult women and only comprise a small percentage of the tolerable intake level.”
Reacting to the survey, the CRN’s Dr Hathcock said it was a “very reassuring report, with levels as low as one can hope for”. However, the results also showed that lead is not an issue for dietary supplements, “because we have these kinds of results”.
“I am glad the tests were done using state-of-the-art methodology,” he said.
Dr Fabricant told NutraIngredients-USA.com: “The FDA testing also begins to address the science behind the actual levels of exposure, which is critical in the current regulatory climate which is based on risk-assessment.
“From our vantage, having a third party GMP certification program we were very pleased to see that those products making GMP label statements had lower mean lead mass fractions than those without.
“While not conclusive it certainly bodes well for the value of third-party programs and their ability to assist manufacturers in producing quality products," added Dr Fabricant.
The full list of supplements and lead mass fraction and exposure results is available free of charge at the American Chemical Society’s website: http://pubs.acs.org .
Source: Journal of Agricultural and Food ChemistryPublished online ahead of print, ASAP Article, doi: 10.1021/jf801236w"Lead in Women’s and Children’s Vitamins"Authors: W.R. Mindak, J. Cheng, B.J. Canas, P.M. Bolger