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DRIDIETARY REFERENCE INTAKES FOR Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc A Report of the Panel on Micronutrients, Subcommittees on Upper Reference Levels of Nutrients and of Interpretation and Uses of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes Food and Nutrition Board Institute of Medicine NATIONAL ACADEMY PRESS Washington, D.C.
NATIONAL ACADEMY PRESS â¢ 2101 Constitution Avenue, N.W. â¢ Washington, DC 20418 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This project was funded by the U.S. Department of Health and Human Services Office of Disease Prevention and Health Promotion, Contract No. 282-96-0033, T03; the National Institutes of Health Office of Dietary Supplements; the Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition and Physical Activity; Health Canada; the Institute of Medicine; the Dietary Reference Intakes Private Foundation Fund, including the Dannon Institute and the Inter- national Life Sciences Institute; and the Dietary Reference Intakes Corporate Donorsâ Fund. Contributors to the Fund to date include Daiichi Fine Chemicals, Inc., Kemin Foods, L.C., M&M/Mars, Mead Johnson Nutritionals, Nabisco Foods Group, Natural Source Vitamin E Association, Roche Vitamins Inc., U.S. Borax, and Weider Nutritional Group. The opinions or conclusions expressed herein do not necessarily reflect those of the funders. Library of Congress Cataloging-in-Publication Data Dietary reference intakes for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc : a report of the Panel on Micronutrients ... [et al.], Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. p. cm. Includes bibliographical references and index. ISBN 0-309-07279-4 (pbk.)âISBN 0-309-07290-5 (hc.) 1. Trace elements in nutrition. 2. Vitamin A in human nutrition. 3. Vitamin K. 4. Reference Values (Medicine) I. Institute of Medicine (U.S.). Panel on Micronutrients. QP534 .D54 2002 612.3â²924- -dc21 2001052139 This report is available for sale from the National Academy Press, 2101 Constitution Avenue, N.W., Box 285, Washington, DC 20055; call (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area), or visit the NAPâs on-line bookstore at http://www.nap.edu. For more information about the Institute of Medicine or the Food and Nutrition Board, visit the IOM home page at http://www.iom.edu. Copyright 2001 by the National Academy of Sciences. All rights reserved. Printed in the United States of America The serpent has been a symbol of long life, healing, and knowledge among almost all cultures and religions since the beginning of recorded history. The image adopted as a logotype by the Institute of Medicine is based on a relief carving from ancient Greece, now held by the Staatliche Museen in Berlin.
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National Academy of Sciences National Academy of Engineering Institute of Medicine National Research Council The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M. Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engi- neering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm. A. Wulf is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academyâs purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. Wm. A. Wulf are chairman and vice chairman, respectively, of the National Research Council.
PANEL ON MICRONUTRIENTS ROBERT RUSSELL (Chair), Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts JOHN L. BEARD, Department of Nutrition, The Pennsylvania State University, University Park ROBERT J. COUSINS, Center for Nutritional Sciences, University of Florida, Gainesville JOHN T. DUNN, University of Virginia Health System, Charlottesville GUYLAINE FERLAND, Department of Nutrition, University of Montreal, Quebec, Canada K. MICHAEL HAMBIDGE, Department of Pediatrics, University of Colorado Health Sciences Center, Denver SEAN LYNCH, Veterans Administration Medical Center, Hampton, Virginia JAMES G. PENLAND, U.S. Department of Agriculture Human Nutrition Research Center, Grand Forks, North Dakota A. CATHARINE ROSS, Department of Nutrition, The Pennsylvania State University, University Park BARBARA J. STOEKER, Department of Nutritional Sciences, Oklahoma State University, Stillwater JOHN W. SUTTIE, Department of Biochemistry, University of Wisconsin, Madison JUDITH R. TURNLUND, U.S. Department of Agriculture Western Human Nutrition Research Center, Davis, California KEITH P. WEST, Center for Human Nutrition, Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland STANLEY H. ZLOTKIN, Departments of Pediatrics and Nutritional Sciences, The Hospital for Sick Children and The University of Toronto, Ontario, Canada Consultants LEWIS BRAVERMAN, School of Medicine, Harvard University, Boston, Massachusetts FRANCOISE DELANGE, Department of Pediatrics, HÃ´pital Saint-Pierre, Brussels, Belgium Staff PAULA R. TRUMBO, Study Director ALICE L. VOROSMARTI, Research Associate MICHELE RAMSEY, Senior Project Assistant v
SUBCOMMITTEE ON UPPER REFERENCE LEVELS OF NUTRIENTS IAN C. MUNRO (Chair), CanTox, Inc., Mississauga, Ontario, Canada GEORGE C. BECKING, Phoenix OHC, Kingston, Ontario, Canada RENATE D. KIMBROUGH, Institute for Evaluating Health Risks, Washington, D.C. RITA B. MESSING, Division of Environmental Health, Minnesota Department of Health, St. Paul SANFORD A. MILLER, Graduate School of Biomedical Sciences, University of Texas Health Sciences Center, San Antonio HARRIS PASTIDES, School of Public Health, University of South Carolina, Columbia JOSEPH V. RODRICKS, The Life Sciences Consultancy LLC, Washington, D.C. IRWIN H. ROSENBERG, Clinical Nutrition Division, the Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University and New England Medical Center, Boston, Massachusetts STEVE L. TAYLOR, Department of Food Science and Technology and Food Processing Center, University of Nebraska, Lincoln JOHN A. THOMAS, Retired, University of Texas Health Science Center at San Antonio GARY M. WILLIAMS, Department of Pathology, New York Medical College, Valhalla Staff SANDRA SCHLICKER, Study Director ELISABETH A. REESE, Research Associate MICHELE RAMSEY, Senior Project Assistant vi
SUBCOMMITTEE ON INTERPRETATION AND USES OF DIETARY REFERENCE INTAKES SUZANNE MURPHY (Chair), Cancer Research Center of Hawaii, University of Hawaii, Honolulu LENORE ARAB, University of North Carolina School of Public Health, Chapel Hill SUSAN I. BARR, University of British Columbia, Vancouver SUSAN T. BORRA, International Food Information Council, Washington, D.C. ALICIA CARRIQUIRY, Iowa State University, Ames BARBARA L. DEVANEY, Mathematica Policy Research, Princeton, New Jersey JOHANNA T. DWYER, Frances Stern Nutrition Center, New England Medical Center and Tufts University, Boston, Massachusetts JEAN-PIERRE HABICHT, Cornell University, Ithaca, New York HARRIET V. KUHNLEIN, Centre for Indigenous Peoplesâ Nutrition and Environment, McGill University, Ste. Anne de Bellevue, Quebec, Canada Staff MARY POOS, Study Director ALICE L. VOROSMARTI, Research Associate SHELLEY GOLDBERG, Senior Project Assistant vii
STANDING COMMITTEE ON THE SCIENTIFIC EVALUATION OF DIETARY REFERENCE INTAKES VERNON R. YOUNG (Chair), Laboratory of Human Nutrition, School of Science, Massachusetts Institute of Technology, Cambridge JOHN W. ERDMAN, JR. (Vice-Chair), Division of Nutritional Sciences, College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign LINDSAY H. ALLEN, Department of Nutrition, University of California, Davis STEPHANIE A. ATKINSON, Department of Pediatrics, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada ROBERT J. COUSINS, Center for Nutritional Sciences, University of Florida, Gainesville JOHANNA T. DWYER, Frances Stern Nutrition Center, New England Medical Center and Tufts University, Boston, Massachusetts JOHN D. FERNSTROM, University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, Pittsburgh, Pennsylvania SCOTT M. GRUNDY, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas SANFORD A. MILLER, Graduate School of Biomedical Sciences, University of Texas Health Science Center, San Antonio WILLIAM M. RAND, Department of Family Medicine and Community Health, Tufts University School of Medicine, Boston, Massachusetts U.S. Government Liaison ELIZABETH CASTRO, Office of Disease Prevention and Health Promotion, U.S. Department of Health and Human Services, Washington, D.C. Canadian Government Liaison PETER W.F. FISCHER, Nutrition Research Division, Health Protection Branch, Health Canada, Ottawa Consultant GEORGE BEATON, GHB Consulting, Willowdale, Ontario, Canada Staff ALLISON A. YATES, Study Director SANDRA SCHLICKER, Senior Program Officer MARY POOS, Senior Program Officer viii
PAULA TRUMBO, Senior Program Officer ALICE L. VOROSMARTI, Research Associate KIMBERLY FREITAG, Research Assistant MICHELE RAMSEY, Senior Project Assistant GAIL E. SPEARS, Administrative Assistant ix
FOOD AND NUTRITION BOARD CUTBERTO GARZA (Chair), Division of Nutrition, Cornell University, Ithaca, New York ALFRED H. MERRILL, JR. (Vice Chair), Department of Biochemistry, Emory Center for Nutrition and Health Sciences, Emory University, Atlanta, Georgia ROBERT M. RUSSELL (Vice Chair), Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts VIRGINIA A. STALLINGS (Vice Chair), Division of Gastroenterology and Nutrition, The Childrenâs Hospital of Philadelphia, Pennsylvania LARRY R. BEUCHAT, Center for Food Safety and Quality Enhancement, University of Georgia, Griffin BENJAMIN CABALLERO, Center for Human Nutrition, Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland FERGUS M. CLYDESDALE, Department of Food Science, University of Massachusetts, Amherst ROBERT J. COUSINS, Center for Nutritional Sciences, University of Florida, Gainesville JOHANNA T. DWYER, Frances Stern Nutrition Center, New England Medical Center and Tufts University, Boston, Massachusetts SCOTT M. GRUNDY, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas SHIRIKI KUMANYIKA, University of Pennsylvania School of Medicine, Philadelphia LYNN PARKER, Child Nutrition Programs and Nutrition Policy, Food Research and Action Center, Washington, D.C. ROSS L. PRENTICE, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington A. CATHARINE ROSS, Department of Nutrition, The Pennsylvania State University, University Park ROBERT E. SMITH, R.E. Smith Consulting, Inc., Newport, Vermont STEVE L. TAYLOR, Department of Food Science and Technology and Food Processing Center, University of Nebraska, Lincoln Staff ALLISON A. YATES, Director GAIL E. SPEARS, Administrative Assistant GARY WALKER, Financial Associate x
Preface This report is one in a series that presents a comprehensive set of reference values for nutrient intakes for healthy U.S. and Canadian populations. It is a product of the Food and Nutrition Board of the Institute of Medicine (IOM) working in cooperation with Canadian scientists. The report establishes a set of reference values for vitamin A, vitamin K, chromium, copper, iodine, iron, manganese, molybdenum, and zinc to replace previously published Recommended Dietary Allowances (RDAs) and Recommended Nutrient Intakes (RNIs) for the United States and Canada. The report also examines data about arsenic, boron, nickel, silicon, and vanadium. Although all refer- ence values are based on data, available data often were scanty or drawn from studies that had limitations in addressing the various questions that confronted the Panel. Thus, although governed by reasoning, informed judgments often were required in setting ref- erence values. The reasoning used is described for each nutrient in Chapters 4 through 13. Close attention was given to the evidence relating intake of micro- nutrients to reduction of the risk of chronic disease, and the daily amounts needed to maintain normal status based on biochemical indicators and daily body losses. In addition, a major task of the Panel on Micronutrients, Subcommittee on Upper Reference Levels of Nutrients (UL Subcommittee), and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (DRI Com- mittee) was to analyze the evidence on beneficial and adverse effects xi
xii PREFACE of arsenic, boron, nickel, silicon, and vanadiumâin the context of setting Dietary Reference Intakes (DRIs). Another major task of the report was to outline a research agenda to provide a basis for future public policy decisions related to rec- ommended intakes of these micronutrients and ways to achieve those intakes. Many of the questions that were raised about require- ments for and recommended intakes of micronutrients were not answered fully because of inadequacies in the published database. Apart from studies of overt deficiency diseases, there is a dearth of studies that address specific effects of inadequate micronutrient intakes on health status. For most of the micronutrients, there is no direct information that permits estimating the amounts required by children, adolescents, the elderly, and pregnant and lactating women. For four of the micronutrients, data were sparse for setting Tolerable Upper Intake Levels (ULs), precluding reliable estimates of how much can be ingested safely. For some of these micronutrients, there are questions about how much is contained in the foods North Americans eat. Readers are urged to recognize that the establishment of DRIs is an iterative process that is expected to evolve as its conceptual framework is applied to new nutrients and food components. With more experience, the proposed models for establishing reference intakes of nutrients and food components that play a role in health will be refined. Also, as new information or new methods of analysis are adopted, these reference values undoubtedly will be reassessed. Thus, because the project is ongoing, many comments were solicited and have been received on the reports that have been previously published. Refinements that have resulted from this iterative pro- cess have been included in the general information regarding ap- proaches used (Chapters 1 through 3) and in the discussion of uses of DRIs (Chapter 14 in this report). The Subcommittee on the Interpretation and Uses of Dietary Ref- erence Intakes (Uses Subcommittee), formed subsequent to the release of the first two reports, has been primarily responsible for chapter 14, which addresses major issues conceptually included since the beginning of the DRI process that relate to the anticipated uses and applications of reference values as developed further by the Uses Subcommittee. This report reflects the work of the Food and Nutrition Boardâs DRI Committee, its expert Panel on Micronutrients, and the UL and Uses Subcommittees. We gratefully acknowledge the support of the government of Canada and Canadian scientists in this initiative
PREFACE xiii that represents a pioneering first step in the standardization of nutrient reference intakes at least within a major part of one conti- nent. A brief description of the overall project of the DRI Com- mittee and of the panelâs task is given in Appendix A. We hope that the critical, comprehensive analyses of available information and knowledge gaps contained in this initial series of reports will assist the private sector, foundations, universities, government laboratories, and other institutions with the development of a productive re- search agenda for the next decade. The DRI Committee, the Panel on Micronutrients, the UL and Uses Subcommittees, and the Food and Nutrition Board wish to extend sincere thanks to the many experts who assisted with this report by giving presentations, providing written materials, partici- pating in discussions, analyzing data, and other means. Many, but far from all, of these individuals are named in Appendix B. Special thanks go to George Beaton and the staff at the National Center for Health Statistics, the Food Surveys Research Group of the Agricul- tural Research Service, ENVIRON Corporation, Health Technomics, and the Department of Statistics at Iowa State University for exten- sive analyses of survey data. The respective chairs and members of the Panel on Micronutrients and subcommittees have performed their work under great time pressure. Their dedication made the completion of this report pos- sible. All gave of their time willingly and without financial reward; the public and the science and practice of nutrition are among the major beneficiaries. The DRI Committee and the Food and Nutrition Board wish to acknowledge, in particular, the commitment shown by Robert Russell, Chair of the Panel on Micronutrients, who guided this diffi- cult project through challenging and innovative paths. His ability to keep the effort and various biases moving in a positive direction is very much appreciated. Thanks are also due to the DRI Committee members, Lindsay Allen and William Rand, who served as in-depth internal reviewers for this report. Special thanks also are expressed to the staff of the Food and Nutrition Board and foremost to Paula Trumbo, who was the study director for the panel and without whose assistance, both intellectual and managerial, this report would neither have been as polished nor as timely in its release. It is, of course the Food and Nutrition Board staff who get much of the work completed and so the panel, committees, and the Food and Nutrition Board wish to thank Allison Yates, Director of the Food and Nutrition Board, for her and her
xiv PREFACE staffâs constant assistance. Thus, we also recognize and appreciate the contributions of Sandra Schlicker, Mary Poos, Elisabeth Reese, Alice Vorosmarti, Gail Spears, and Michele Ramsey and thank Pat Stephens for editing the manuscript, Jacqueline Dupont for tech- nical review, and Claudia Carl for assistance with publication. Vernon Young Chair, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes Cutberto Garza Chair, Food and Nutrition Board
Reviewers This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the NRCâs Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its pub- lished report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and respon- siveness to the study charge. The review comments and draft manu- script remain confidential to protect the integrity of the delibera- tive process. We wish to thank the following individuals for their review of this report: Sarah L. Booth, Tufts University James D. Cook, Kansas University Medical Center Mark L. Failla, University of North Carolina Jeanne Freeland-Graves, University of Texas James K. Friel, Memorial University of Newfoundland Walter Mertz, Rockville, Maryland Phylis B. Moser-Veillon, University of Maryland Robert S. Parker, Cornell University John B. Stanbury, Massachusetts General Hospital Clive E. West, Wageningen Agricultural University Although the reviewers listed above have provided many construc- tive comments and suggestions, they were not asked to endorse the xv
xvi REVIEWERS conclusions or recommendations nor did they see the final draft of the report before its release. The review of this report was overseen by Kurt J. Isselbacher, Massachusetts General Hospital and Ronald W. Estabrook, University of Texas Southwestern Medical Center at Dallas. Appointed by the National Research Council and Institute of Medicine, they were responsible for making certain that an inde- pendent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committees and the institution.
Contents SUMMARY 1 What Are Dietary Reference Intakes?, 2 Approach for Setting Dietary Reference Intakes, 7 Nutrient Functions and the Indicators Used to Estimate Requirements, 10 Criteria and Proposed Values for Tolerable Upper Intake Levels, 16 Using Dietary Reference Intakes to Assess Nutrient Intakes of Groups, 19 Consideration of the Risk of Chronic Degenerative Disease, 22 Research Recommendations, 26 1 INTRODUCTION TO DIETARY REFERENCE INTAKES 29 What Are Dietary Reference Intakes?, 29 Categories of Dietary Reference Intakes, 30 Parameters for Dietary Reference Intakes, 36 Summary, 42 References, 42 2 OVERVIEW AND METHODS 44 Methodological Considerations, 45 Estimates of Nutrient Intake, 54 Dietary Intakes in the United States and Canada, 55 Summary, 58 References, 58 xvii
xviii CONTENTS 3 A MODEL FOR THE DEVELOPMENT OF TOLERABLE UPPER INTAKE LEVELS 60 Background, 60 A Model for the Derivation of Tolerable Upper Intake Levels, 62 Risk Assessment and Food Safety, 62 Application of the Risk Assessment Model to Nutrients, 67 Steps in the Development of the Tolerable Upper Intake Level, 71 Intake Assessment, 79 Risk Characterization, 79 References, 80 4 VITAMIN A 82 Summary, 82 Background Information, 83 Selection of Indicators for Estimating the Requirement for Vitamin A, 97 Factors Affecting the Vitamin A Requirement, 106 Findings by Life Stage and Gender Group, 110 Intake of Vitamin A, 122 Tolerable Upper Intake Levels, 125 Research Recommendations for Vitamin A, 146 References, 146 5 VITAMIN K 162 Summary, 162 Background Information, 162 Selection of Indicators for Estimating the Requirement for Vitamin K, 165 Factors Affecting the Vitamin K Requirement, 173 Findings by Life Stage and Gender Group, 176 Intake of Vitamin K, 184 Tolerable Upper Intake Levels, 187 Research Recommendations for Vitamin K, 189 References, 189 6 CHROMIUM 197 Summary, 197 Background Information, 197 Selection of Indicators for Estimating the Requirement for Chromium, 202
CONTENTS xix Factors Affecting the Chromium Requirement, 204 Findings by Life Stage and Gender Group, 205 Intake of Chromium, 211 Tolerable Upper Intake Levels, 213 Research Recommendations for Chromium, 216 References, 217 7 COPPER 224 Summary, 224 Background Information, 224 Selection of Indicators for Estimating the Requirement for Copper, 229 Factors Affecting the Copper Requirement, 233 Findings by Life Stage and Gender Group, 235 Intake of Copper, 245 Tolerable Upper Intake Levels, 246 Research Recommendations for Copper, 252 References, 252 8 IODINE 258 Summary, 258 Background Information, 258 Selection of Indicators for Estimating the Requirement for Iodine, 262 Factors Affecting the Iodine Requirement, 267 Findings by Life Stage and Gender Group, 268 Intake of Iodine, 277 Tolerable Upper Intake Levels, 278 Research Recommendations for Iodine, 284 References, 284 9 IRON 290 Summary, 290 Background Information, 290 Selection of Indicators for Estimating the Requirement for Iron, 300 Factors Affecting the Iron Requirement, 311 Findings by Life Stage and Gender Group, 316 Intake of Iron, 355 Tolerable Upper Intake Levels, 356 Research Recommendations for Iron, 378 References, 378
xx CONTENTS 10 MANGANESE 394 Summary, 394 Background Information, 394 Selection of Indicators for Estimating the Requirement for Manganese, 397 Factors Affecting the Manganese Requirement, 401 Findings by Life Stage and Gender Group, 402 Intake of Manganese, 407 Tolerable Upper Intake Levels, 408 Research Recommendations for Manganese, 414 References, 415 11 MOLYBDENUM 420 Summary, 420 Background Information, 420 Selection of Indicators for Estimating the Requirement for Molybdenum, 422 Factors Affecting the Molybdenum Requirement, 424 Findings by Life Stage and Gender Group, 425 Intake of Molybdenum, 432 Tolerable Upper Intake Levels, 433 Research Recommendations for Molybdenum, 439 References, 439 12 ZINC 442 Summary, 442 Background Information, 442 Selection of Indicators for Estimating the Requirement for Zinc, 447 Factors Affecting the Zinc Requirement, 454 Findings by Life Stage and Gender Group, 458 Intake of Zinc, 480 Tolerable Upper Intake Levels, 481 Research Recommendations for Zinc, 488 References, 489 13 ARSENIC, BORON, NICKEL, SILICON, AND VANADIUM 502 Summary, 502 Arsenic, 503 Boron, 510 Nickel, 521 Silicon, 529
CONTENTS xxi Vanadium, 532 References, 543 14 USES OF DIETARY REFERENCE INTAKES 554 Overview, 554 Assessing Nutrient Intakes of Individuals, 555 Assessing Nutrient Intakes of Groups, 558 Planning Nutrient Intakes of Individuals, 562 Planning Nutrient Intakes of Groups, 563 Nutrient-Specific Considerations, 564 Summary, 576 References, 578 15 A RESEARCH AGENDA 580 Approach, 580 Major Knowledge Gaps, 581 The Research Agenda, 584 APPENDIXES A Origin and Framework of the Development of Dietary Reference Intakes, 587 B Acknowledgments, 591 C Dietary Intake Data from the Third National Health and Nutrition Examination Survey (NHANES III), 1988â1994, 594 D Dietary Intake Data from the Continuing Survey of Food Intakes By Individuals (CSFII), 1994â1996, 644 E Dietary Intake Data from the U.S. Food and Drug Administration Total Diet Study, 1991â1997, 654 F Canadian Dietary Intake Data, 1990, 674 G Biochemical Indicators for Iron, Vitamin A, and Iodine from the Third National Health and Nutrition Examination Survey (NHANES III), 1988â1994, 680 H Comparison of Vitamin A and Iron Intake and Biochemical Indicators from the Third National Health and Nutrition Examination Survey (NHANES III), 1988â1994, 692 I Iron Intakes and Estimated Percentiles of the Distribution of Iron Requirements from the Continuing Survey of Food Intakes by Individuals (CSFII), 1994â1996, 697 J Glossary and Acronyms, 704 K Conversion of Units, 709 L Options for Dealing with Uncertainties, 710 M Biographical Sketches of Panel and Subcommittee Members, 715
xxii CONTENTS INDEX 729 SUMMARY TABLE, Dietary Reference Intakes: Recommended Intakes for Individuals, Vitamins 770 SUMMARY TABLE, Dietary Reference Intakes: Recommended Intakes for Individuals, Elements 772
DRI DIETARY REFERENCE INTAKES FOR Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc