ITIMll ~ INERAL HELP OR Hi\RM? @ w Charles W. Marshall, Ph.D. Sf~JXt EDITED BY SfEPHEN BARRETT. M.D VITAMINS AND MINERALS: HELP OR HARM? Charles W. Marshall, Ph.D. A People's Health Library Book Edited by Stephen Barrett, M.D. George F. Stickley Company [JI 210 W. Washington Square Philadelphia, PA 19106 The People's Health Library is a series of easy-to-read books written by experts who explain health and health care concepts for the general public. For a com­ plete list of titles, send a self-addressed, stamped envelope to the George F. Stickley Company, 210 West Washington Square, Philadelphia, PA 19106. First published © 1983, hardcover edition, by the George F. Stickley Company. Copyright © 1985, 1986, paperback edition, revised and up­ dated by the George E Stickley Company. ISBN-89313-072-9 All Rights Reserved. No part of this book may be reproduced in any form without permission from the publisher. Printed and Manufactured in the United States and published by the George F. Stickley Company, 210 West Washington Square, Phila., Pa. 19106. iv Contents Foreword By Dr. William J. Darby ix Introduction xi FAITH VS. REASON 1. How Supplements are Promoted 1 2. Danger in the Bottle 6 3. Science vs. Quackery 12 4. Common Beliefs-How Tme? 20 5. What Is A Vitamin? 27 6. Non-Vitamins and Phony Vitamins 32 FAT-SOLUBLE VITAMINS 7. Vitamin A Can Help or Harm 40 8. Vitamin D Can Help or Harm 52 9. Vitamin E Can Help or Harm 64 10. Vitamin K Can Help or Hann 80 WATER-SOLUBLE VITAMINS 11. B·Vitamins Can Help or Bann 85 12. Vitamin C Can Help or Harm 107 MEGAVITAMIN CLAIMS DEBATED 13. Can Megavitamin C Help Colds or Other Infections? 122 14. Can Megavitamin E Help the Heart, Prolong Life, Increase Sexuality or Do Anything EJse for You? 133 15. Can Megavitamins Help Mental Health? 144 16. Can Megavitamins Help Against Cancer? 152 17. Can Megavitamins Help Reduce Cholesterol and Protect Against Heart Disease? 165 MINERALS CAN HELP OR HARM 18. The Macrominerals: Calcium, Phpsphorus, Magnesium, Sodium, Potassium and Chloride 171 19. Zinc, Selenium and Copper 181 20. Iron, Iodine, Fluorine and Other Microminerals 195 SENSIBLE NUTRITION 21. Who is at Risk for Deficiency? 205 22. Wise Food Selection 220 23. Heart Disease, Cancer and Diet 227 24. Should You Take Supplements? 236 Appendix A. Glossary 239 Appendix B. Recommended Dietary Allowances (RDAs) 248 U.S. Recommended Daily Allowances (U.S. RDAs) 249 Appendix C. Recommended Reading 250 Index 252 v This book is dedicated to: Charles Glen King, Ph.D. Emeritus Professor of Chemistry Columbia College of Physicians and Surgeons and Thomas H. Jukes, Ph.D. Professor of Medical Physics and Lecturer in Nutrition University of California (Berkeley) Dr. King, co-discoverer of vitamin C, helped to organize Columbia University's Institute of Human Nutrition and was a founding Scien­ tific Director and later President of the Nutrition Foundation. Dr. Jukes, another pioneer vitamin researcher, contributed to the understanding of several B-vitamins, particularly pantothenic acid, and has crusaded relentlessly against dangerous vitamin misinformation and other forms of nutrition quackery. vi Acknowledgments In researching and writing this book, I leaned heavily on the generous assistance of many, many persons. Despite the risk of omitting someone who helped, I wish to express my gratitude to the following: Dr. Thomas F. Gallagher, Professor of Biochemistry, who long ago taught me the scientific method. Dr. Victor Herbert, whose indignation against health quackery inspired me in January of 1975 to start the research for this book. Dr. Stephen Barrett, my trusty editor, whose expert guidance helped transform an overly long manuscript into a readable, reliable book. Mrs. Jeanne Hartenstein, Chief Librarian, Health Sciences Library, Bronson Methodist Hospital, Kalamazoo, Michigan, who scoured libraries nationwide to obtain copies of references difficult to find. Mrs. Louise Lasworth, Librarian in the Science Library of G. D. Searle & Co., Skokie, Illinois. The Upjohn Company of Kalamazoo for granting me guest privileges in its medical-science library; and also its librarians, Mrs. Lyga Greenfield and Mrs. Herberta Carver. Mrs. Frances McAfee, who helped type the original manuscript under difficult circumstances. Mrs. Shirlee Cummins, who typed the entire second draft manuscript under rush request. Mrs. Kathleen Onofrio, Chief Librarian, South Haven (Michigan) Me­ morial Library, who read much of the original manuscript and offered comments based on her estimate of the general public's interest in vitamins. A very special appreciation goes to the following scientists who read one or more selected chapters of the first and/or the final draft of my manuscript and offered constructive criticism and encouragement. Roslyn Alfin-Slater, Ph.D., Professor and Chairman, Department of Environmental and Nutritional Sciences, School of Public Health, Univer­ sity of California, Los Angeles. Terence Anderson, M.D., Head, Department of Health Care and Epi­ demiology, University of British Columbia. Jay Arena, M.D., Past-President of the American Academy of Pediatrics and Professor of Pediatrics, Duke Medical Center. Ernest Beutler, M.D., Chairman, Basic and Clinical Research, Scripps Clinical Research Foundation, La Jolla, California. John Bieri, Ph.D., National Institutes of Health (now retired). vii viii Acknowledgments George Briggs, Ph.D., Professor and Past-Chairman of the Department of Nutritional Sciences, University of California, Berkeley. Charles Butterworth, M.D., Professor of Medicine and Nutrition, Uni­ ·versity of Alabama. William J. Darby, M.D., Ph.D., Emeritus Professor of Medicine, Van­ derbilt University School of Medicine. Hector DeLuca, Ph.D., Professor and Chairman of the Department of Biochemistry, University of Wisconsin. Alfred Harper, Ph.D., Professor of Biochemistry, University of Wisconsin. Victor Herbert, M.D., J.D., Chief of Hematology and Nutrition, V.A. Medical Center, Bronx, New York. Thomas Jukes, Ph.D., Professor of Medical Physics and Lecturer in Nutrition, University of California, Berkeley. David Kritchevsky, Ph.D., Associate Director, Wistar Institute of Anat­ omy and Biology, Philadelphia. Morris A. Lipton, M.D., Professor of Psychiatry and Director, Biologi­ cal Sciences Research Center of the Child Development Research Institute, University of North Carolina, Chapel Hill. George V. Mann, M.D., Professor of Medicine, Vanderbilt University. Jacob Nevyas, Ph.D., Sc.D., Emeritus Professor of Chemistry, Philadel­ phia College of Optometry. Irwin Rosenberg, M.D., Professor of Medicine, Director of the Clinical Nutrition Research Center, University of Chicago. Howerde E. Sauberlich, Ph.D., Professor and Director, Division of Ex­ perimental Nutrition, Department of Nutritional Sciences, University of Alabama. William Sebren, Ph.D., retired Director of the Institute of Human Nu­ trition, Columbia College of Physicians & Surgeons. Noel W. Solomons, M.D., Professor of Nutrition and Food Science, Massachusetts Institute of Technology. Fredrick J. Stare, M.D., Ph.D., Emeritus Professor of Nutrition, Har­ vard University School of Public Health. Philip White, Sc.D., Director, American Medical Association Division of Personal and Public Health Policy. Hilda S. White,Ph.D., Nutrition Consultant, Wilmette, Illinois. Myron Winick, M.D., Professor of Pediatrics and Nutrition and Direc­ tor, Institute of Human Nutrition, Columbia College of Physicians & Surgeons. George Wolf, Ph.D., Professor, Department of Nutrition & Food Sci­ ence, Massachusetts Institute of Technology. Vernon Young, Ph.D., Professor of Nutritional Biochemistry, Massa­ chusetts Institute of Technology. Foreword Millions of Americans now dose themselves frequently with vitamins and minerals they don't need. Some do this out of fear that they won't get enough from their food; while others hope that extra large quantities of nutrients can prevent or cure a wide range of diseases. Although thousands of books encourage self-medication with nutrients, only a few warn of the dangers involved. Yet the scientific evidence is clear: all sub­ stances, even vitamins, are toxic in sufficient excess-and legitimate medi­ cal uses of large amounts (megadoses) are quite rare. How did vitamins become so popular? Dr. Marshall explains that al­ though the word "vitamin"-like "vital" and "vitality"-suggests great importance to health, there is no simple way for individuals to measure how much they need. These facts, combined with a large army of Pi~d Pipers and the persuasive power of the mass media, have produced a $3 billion/year industry. During many years as a nutrition educator, I have painfully observed the growth of this problem. Vitamins and Minerals: Help or Harm? is a much-needed book, useful to laypersons and health professionals alike. It answers basic questions like: What are vitamins and minerals? What do they do for you? How much of them do you need? Who is at risk for deficiency? Which foods contain which nutrients? How can you tell if you are getting enough? How much is too much? What happens if you ingest more than you need? When can vitamins and minerals be used legitimately in the prevention and treat­ ment of disease? In this book you will find documented facts that com­ pletely counter the myths of Pied Pipers. While there is little scientific controversy about vitamins, there is genu­ ine controversy about the role of diet in producing heart diseases and can­ cer. This book examines these issues and provides practical advice for healthy eating. Adelle Davis, a major promoter of nutrition misinformation, dominated the talk-show circuit until her death in 1974. Her books sold millions of copies and still are popular. Did you know that much of her advice was irresponsible? Or that her book Lefs Have Healthy Children was quietly recalled from the market after the death of a child whose mother followed the book's advice? You will find the details in Dr. Marshall's book. Linus Pauling's zealous advocacy has also played a big role in the current vita­ min boom.