Just a few weeks after the high profile withdrawal of supplements produced by Nature's Way following the discovery of excessive amounts of lead, the US-based independent product tester ConsumerLab.com has reported that up to 10 per cent of certain mineral supplements could also be contaminated.
Over the last nine months, ConsumerLab.com has evaluated 56 supplements containing iron, magnesium or potassium, and discovered that between 5 and 10 per cent of them were contaminated with lead.
With more than 11 million bottles of these minerals bought each year in the US alone, this has the potential to be a serious problem. But as ConsumerLab.com pointed out, it is also a problem which could easily be avoided.
"Mineral supplements can be lifesaving, but should not increase the risk of lead poisoning," said Tod Cooperman, ConsumerLab.com's president.
"Lead contamination has long been an issue with mineral supplements. We were pleased two years ago to find that none of the calcium supplements we tested had unacceptable lead levels. However, more recently, we have been disturbed to find lead contamination not only among potassium supplements, as reported today, but also in magnesium (reported in May) and iron supplements (reported last October). Manufacturers must focus on getting the lead out of all supplements - which can easily be done."
In its latest review of potassium supplements, ConsumerLab.com found lead contamination in one of the 18 products tested. This product contained some of its potassium in the form of potassium chloride, which has a recognised risk of containing higher lead levels. If used to treat potassium deficiency, a daily dose of the contaminated product would contain about 10 to 20 micrograms of lead, the organisation said, compared to the estimated average total daily lead exposure in the US of less than 5 mcg per day.
None of the other products contained more than 0.1 mcg of lead per tablet.
Lead exposure is particularly dangerous for foetuses, infants, young children and pregnant or lactating women, whose consumption of lead should not exceed 6 mcg per day. Lead can be transferred from mother to child and even low levels of lead can adversely affect children's neuro-behavioural development and cognitive function. In adults, lead at somewhat higher levels can cause elevated blood pressure, anaemia and adversely affect the nervous and reproductive systems.
ConsumerLab.com's earlier tests revealed that one of 19 iron supplements and two of 19 magnesium supplements were found to be contaminated with lead. Other problems, such as too little or too much mineral, were also found among some products.
The full list the products tested by ConsumerLab.com can be found on the website.