SAFETY LEVELS

US Food and Nutrition Board (FNB) Tolerable Upper Intake Level
FNB defines the UL as “the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects to almost all individuals in the general population.” The UL is calculated by identifying a No Observed Adverse Intake Level (NOAEL) (or the Lowest Observed Adverse Intakes, or LOAEL) and dividing by an uncertainty factor (UF), which is the numerical value assigned to uncertainty in the data.

The UL was developed on the principle of risk assessment. The first step in the process of developing the UL was hazard identification. Six key issues addressed in the data evaluation were: (1) evidence of adverse effects in humans, (2) causality, (3) relevance of experimental data, (4) mechanisms of toxic action, (5) quality and completeness of the data base, and (6) identification of distinct and highly sensitive populations.

The second step in the process was dose-response assessment. The FNB selected the most appropriate or critical data sets for deriving the UL based on set criteria, and then identified the "no-observed-adverse-effect level" (NOAEL) or, if that was not available, the "lowest-observed adverse-effect level" (LOAEL). These figures were then adjusted based on the degree of uncertainty to arrive at the Upper Limit. The larger the uncertainty, the smaller the Upper Limit, which is consistent with the ultimate goal of the risk assessment—to provide an estimate of a level of intake that will protect a healthy population.

FDA Recommended Dietary Allowances
In 1941, the first Food and Nutrition Board established dietary standards for evaluating the nutritional intakes of large populations. This board developed the first Recommended Dietary Allowances (RDAs). The RDA for a nutrient is based on the amount needed to prevent a deficiency. Every ten years, the RDAs are revised as better scientific knowledge becomes available. The main RDAs include recommendations for energy (calories), protein, and many vitamins and minerals.

As noted, RDA stands for Recommended Dietary Allowances, not Required Daily Amount, as popularly supposed. Because RDAs are developed for groups rather than individuals, RDAs should be used primarily to plan and evaluate the diets of groups of people. You don’t need to eat the RDA for each nutrient every day because your body stores nutrients for later use.

The Council for Responsible Nutrition (CRN)
CRN is a trade association representing the dietary supplement industry. CRN is dedicated to enhancing the health of the U.S. population through responsible nutrition, including the appropriate use of supplements.