Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc

TABLE 2-1 Estimated Growth Factor, by Age Group

Age Group	Growth Factor
7 mo–3 y	0.30
4–8 y	0.15
9–13 y	0.15
14–18 y
Males	0.15
Females	0.0
SOURCE: Proportional increase in protein requirements for growth from FAO/WHO/ UNA (1985) used to estimate the growth factor.

Setting the Tolerable Upper Intake Level for Children

When data are not available to set the Tolerable Upper Intake Level (UL) for children, the UL for adults is extrapolated down using the reference body weights in Table 1-1:

UL_child = UL_adult × Weight_adult/Weight_child.

Method for Extrapolating Data from Young to Older Infants

Using the metabolic weight ratio method to extrapolate data from young to older infants involves metabolic scaling but does not include an adjustment for growth because it is based on a value for a growing infant. To extrapolate from the AI for infants ages 0 through 6 months to an AI for infants ages 7 through 12 months, the following formula is used:

AI₇–_{12 mo} = AI₀–6 mo × F,

where F = (Weight₇–_12mo/Weight0_–6 _mo)0^.75.

Methods for Determining Increased Needs for Pregnancy

It is known that the placenta actively transports certain nutrients from the mother to the fetus against a concentration gradient (Hytten and Leitch, 1971). However, for many nutrients, experimental data that could be used to set an EAR and RDA or an AI for pregnancy are lacking. In these cases, the potential increased need for these nutrients during pregnancy is based on theoretical consid-

Table of Contents

Front Matter R1-R24

Summary 1-28

1 Introduction to Dietary Reference Intakes 29-43

2 Overview and Methods 44-59

3 A Model for the Development of Tolerable Upper Intake Levels 60-81

4 Vitamin A 82-161

5 Vitamin K 162-196

6 Chromium 197-223

7 Copper 224-257

8 Iodine 258-289

9 Iron 290-393

10 Manganese 394-419

11 Molybdenum 420-441

12 Zinc 442-501

13 Arsenic, Boron, Nickel, Silicon, and Vanadium 502-553

14 Uses of Dietary Reference Intakes 554-579

15 A Research Agenda 580-586

Appendix A Origin and Framework of the Development of Dietary Reference Intake 587-590

Appendix B Acknowledgments 591-593

Appendix C Dietary Intake Data from the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994 594-643

Appendix D Dietary Intake Data from the Continuing Survey of Food Intakes by Individuals (CSFII), 1994-1996 644-653

Appendix E Dietary Intake Data from the U.S. Food and Drug Administration Total Diet Study, 1991-1997 654-673

Appendix F Canadian Dietary Intake Data, 1990 674-679

Appendix G Biochemical Indicators for Iron, Vitamin A, and Iodine from the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994 680-691

Appendix H Comparison of Vitamin A and Iron Intake and Biochemical Indicators from the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994 692-696

Appendix I Iron Intakes and Estimated Percentile of the Distribution of Iron Requirements from the Continuing Survey of Food Intakes by Individuals (CSFII), 1994-1996 697-703

Appendix J Glossary and Acronyms 704-708

Appendix K Conversion of Units 709-709

Appendix L Options for Dealing with Uncertainties 710-714

Appendix M Biographical Sketches of Panel and Subcommittee Members 715-728

Index 729-769

Summary Table, Dietary Reference Intakes: Recommended Intakes for Individuals, Vitamins 770-771

Summary Table, Dietary Reference Intakes: Recommended Intakes for Individuals, Elements 772-773

Setting the Tolerable Upper Intake Level for Children

Method for Extrapolating Data from Young to Older Infants

Methods for Determining Increased Needs for Pregnancy