Recently, concerns have been expressed that some excipients in nutriceuticals could carry extra dangers for consumers namely, the largely unquantifiable risks from genetically modified (GM) ingredients. Most health supplements not licensed as medicines are classed as foods and are obliged to warn the consumer on the label if they contain GM ingredients. But supplements that are licensed medicines (for example, some folic acid and cod liver oil supplements) do not have this requirement.

According to the UK Genetic Food Alert (GFA), unless expressly denied by manufacturers, the following may be GM:Derivatives of soya, maize (corn), cotton or rapeseed, including oils, used as carriers for vitamins (A, D and E) in supplements; lecithin and vitamin E; and sweeteners such as dextrose, glucose, dextrins, maltodextrins and sorbitol;

Microorganisms, including certain bacteria, and brewers and bakers yeast or their byproducts, such as aspartame, and enzymes used as processing aids (which may not be listed on the label) such as a acetolactate decarboxylase, a amylase, catalase, chymosin A or B, cyclodextrin glucosyl transferase, b glucanase, glucose isomerase, glucose oxidase, hemicellulase, lipase, triacylglycerol, maltogenic amylase, pectinesterase, protease and pullulanase;

Products such as gelatine, bonemeal and albumin from animals raised on GM ingredients, or injected with GM growth hormones such as BST.

A list of guaranteed GM free supplements can be accessed on the GFA's website (www.geneticfoodalert.supanet.com) along with other information on GM additives in supplements.