Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride

sults. Although presenting a number of plausible risk estimates has clear advantages in that it would seem to reflect more faithfully the true state of scientific understanding, there are no well-established criteria for using such complex results in risk management.

The various approaches to dealing with uncertainties inherent to risk assessment, and discussed in the foregoing sections, are summarized in Table C-1.

As will be seen in the chapters on each nutrient, specific default assumptions for assessing nutrient risks have not been recommended. Rather, the approach calls for case-by-case judgments, with the recommendation that the basis for the choices made be explicitly stated. Some general guidelines for making these choices will, however, be offered.

TABLE C-1 Approaches for Dealing with Uncertainties in a Risk-Assessment Program

Program Model	Advantages	Disadvantages
Case-by-case judgments by experts	Flexibility High potential to maximize use of most relevant scientific information bearing on specific issues	Potential for inconsistent treatment of different issues Difficulty in achieving consensus Need to agree on defaults
Written guidelines specifying defaults for data and model uncertainties (with allowance for departures in specific cases)	Consistent treatment of different issues Maximize transparency of process Allow resolution of scientific disagreements by resort to defaults	May be difficult to justify departure, or to achieve consensus among scientists that departures are justified in specific cases Danger that uncertainties will be overlooked
Assessors asked to present full array of estimates, using all scientifically plausible models	Maximize use of scientific information Reasonably reliable portrayal of true state of scientific understanding	Highly complex characterization of risk, with no easy way to discriminate among estimates Size of required effort may not be commensurate with utility of the outcome

Table of Contents

Front Matter R1-R16

Summary 1-20

1 Dietary Reference Intakes 21-37

2 Calcium and Related Nutrients: Overview and Methods 38-50

3 A Model for the Development of Tolerable Upper Intake Levels 51-70

4 Calcium 71-145

5 Phosphorus 146-189

6 Magnesium 190-249

7 Vitamin D 250-287

8 Fluoride 288-313

9 Uses of Dietary Reference Intakes 314-324

References 325-374

Appendix A Origin and Framework of the Development of Dietary Reference Intakes 375-380

Appendix B Acknowledgments 381-382

Appendix C Options for Dealing with Uncertainties 383-386

Appendix D 1994 CSFII Adjusted Data for Calcium, Phosphorus, and Magnesium 387-393

Appendix E Model for Estimating Calcium Intake for Desirable Calcium Retention 394-398

Appendix F Biographical Sketches of Committee, Subcommittee, Panel Members and Staff 399-412

Index 413-432