Application of the concepts of risk assessment to the study of amino acid supplements

Risk assessment is defined as the use of available scientific information to characterize potentially adverse effects associated with exposure of humans to an agent under known or expected conditions. Practically, risk assessment is intended to provide the scientifically sound basis for regulatory or nonregulatory action to manage the risks in humans from the agent. Therefore, the final goal of risk assessment for supplementary use of amino acids is to provide scientific evidence and scientific logic for the establishment of tolerable upper intake levels (UL) for amino acids. At present, however, execution of risk assessment for amino acids is hampered by deficiencies in necessary scientific information, particularly, experimental or clinical/epidemiological data related to the estimation of no-observed-adverse-effect-levels (NOAEL), and scientific principles for the allocation of uncertainty factors (UF) in extrapolation from experimental/clinical data to the general human population. This paper attempts to identify the scientific data and scientific thoughts/methodologies required for deriving UL or assessing the margin of safety for the supplementary use of amino acids. J. Nutr. 133: 2021 S-2024S, 2003.