A report conducted by Consumerlab.com
has found that many multivitamin manufacturers have dangerous imbalances among the individual vitamins and minerals contained in their products. In fact, more than 30 percent of the multivitamins tested contained more or less of the ingredients claimed on the label.
Among the findings, dangerous ingredients such as Vitamin A, folic acid, niacin, and zinc were found to be notably over the limits set by the Institute of Medicine. Three manufacturers of children's multivitamins were over the daily limits for Vitamin A - too much of which could lead long-term to liver problems and softened bones.
"Upper tolerable limits for niacin and zinc were also exceeded by some of the supplements for young children tested," Reuters reported
. "Excess niacin may cause skin tingling and flushing and high levels of zinc may cause immune deficiency and anemia."
Several men's multivitamin products yielded troubling results in the tests, including elevated exposure to folic acid - which has been tied to increased risk for prostate cancer. Some of the men's multivitamins tested were also contaminated with lead.
This is not the first time Consumerlab.com has found lead in multivitamins. A study in 2007 found lead contamination in women's multivitamins - as was reported here
The report also found that many multivitamin products were short on the ingredients detailed on the packaging.