. "3 A Model for the Development of Tolerable Upper Intake Levels." Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: The National Academies Press, 1997.
The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
DRI DIETARY REFERENCE INTAKES FOR Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride
The process for deriving the UL is described in this section and is summarized in Box 3-1. It includes selection of the critical data set, identification of a critical endpoint with its NOAEL (or LOAEL), and assessment of uncertainty.
Development of Tolerable Upper Intake Levels (ULs)
Evidence of adverse effects in humans
Relevance of experimental data
Mechanisms of toxic action
Quality and completeness of the database
Identification of distinct and highly sensitive subpopulations
Identification of no-observed-adverse-effect level (NOAEL) (or lowest-observed-adverse-effect level [LOAEL]) and critical endpoint
Derivation of a UL
Characterization of the estimate and special considerations
The data evaluation process results in the selection of the most appropriate or critical data set(s) for deriving the UL. Selecting the critical data set includes the following considerations:
Human data are preferable to animal data.
In the absence of appropriate human data, information from an animal species whose biological responses are most like those of humans is most valuable.
If it is not possible to identify such a species or to select such