Melamine, a chemical found in plastics, glue and counter tops, has been discovered in nearly half of samples of popular local nutritional supplements. Dr Gary Gabriels, a researcher in the University of Cape Town's department of pharmacology, tested 138 imported and locally produced supplements and found 64 products had low levels of melamine that were not indicated on the labelling.Gabriels tested the supplements for melamine after a 2008 scandal in China, where high concentrations of the chemical in baby formula killed at least six infants.In large doses, the chemical can cause kidney damage.Melamine contamination of pet food has killed dogs and cats.Gabriels's 2013 study, the results of which were released last week in Nutrition Journal, tested some of the top products on local shelves.Further testing would be needed to see if the products still contained melamine.The melamine content in the samples tested by Gabriels was found to be very low, way below what the World Health Organisation deems to be a tolerable daily intake for humans .Gabriels said users of supplements should not worry if they take the products, but consumer activist Dr Harris Steinman said melamine should not be in supplements."It's like saying that the levels of mercury in a vitamin pill are so low as not to cause harm."Would people want to be regularly consuming a product that contains even a minuscule amount of mercury?"Steinman and Gabriels contend that the World Health Organisation determination of how much melamine is safe does not take into account long-term exposure or repeated use .So how does a consumer know if a supplement or vitamin is safe?Gabriels said standardised lab tests are needed but they would have to be regulated, enforced and accepted by the industry as the required "gold standard".Steinman said vitamins and complementary medicines were not consistently tested.The Health Products Association's Norman Fels said consumers could ask product manufacturers if a pharmacist had been involved in the manufacturing process...