More than 30% of multivitamins tested recently by ConsumerLab.com contained significantly more or less of an ingredient than claimed, or were contaminated with lead, the company reports.
ConsumerLab.com, based in White Plains, New York, is privately held and provides consumer information and independent evaluations of products that affect health and nutrition. According to the company, it is neither owned by nor has a financial interest in any companies that make, distribute or sell consumer products.
Several multivitamin products tested, including three for children, exceeded tolerable upper limits established by the Institute of Medicine for ingredients such as vitamin A, folic acid, niacin and zinc, according to the report posted on www.ConsumerLab.com.
For example, the Institute of Medicine sets a recommended daily allowance (RDA) of 1,300 international units (IU) of vitamin A for children ages 4 to 8 years and an upper tolerable limit of 3,000 IU. However, one multivitamin tested provided 5,000 IU of vitamin A.
In the short term, too much vitamin A may cause nausea and blurred vision, and, in the long-term, may lead to bone softening and liver problems.
Upper tolerable limits for niacin and zinc were also exceeded by some of the supplements for young children tested. Excess niacin may cause skin tingling and flushing and high levels of zinc may cause immune deficiency and anemia.
Tests turned up problems with some men's multivitamin products as well. Two of three men's multivitamins failed to pass testing. One contained too much folic acid, which may increase the risk of prostate cancer, while another was contaminated with lead.
Among four women's multivitamins tested, one provided only 66 percent of its claimed vitamin A; one of five seniors' multivitamins selected contained only 44 percent of its vitamin A; and among three prenatal vitamins, one was short on vitamin
Two out of five general multivitamins were short on ingredients: one provided only 50 percent of its claimed folic acid and the other was missing 30 percent of its calcium.
A vitamin water tested by ConsumerLab.com had 15 times its stated amount of folic acid, so drinking one bottle would exceed the tolerable limit for adults; less than half a bottle would put children over the limit, the company warns on its website.