The safety testing of amino acids

The risk assessment of compounds added to foods or taken as supplements is usually based on hazard characterization studies performed in animal test species. A large default uncertainty factor, or margin or exposure, is usually required to allow for possible species differences and human variability in the toxicokinetics and toxicodynamics of the compound. The development of biomarkers offers the potential to rationalize the risk assessment of amino acids, and to refine the extrapolation of data from animals to humans. The use of high resolution nuclear magnetic resonance spectroscopy applied to readily accessible biological fluids, such as urine and plasma, offers great potential for the identification of toxicologically relevant biomarkers in animal studies that can then be applied to studies in humans.