DIETARY REFERENCE INTAKES
FOR SODIUM AND POTASSIUM
Committee to Review the Dietary Reference Intakes for
Sodium and Potassium
Virginia A. Stallings, Meghan Harrison, and Maria Oria, Editors
Food and Nutrition Board
Health and Medicine Division
A Consensus Study Report of
THE NATIONAL ACADEMIES PRESS
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001
This activity was supported by contracts between the National Academy of Sciences and the Centers for Disease Control and Prevention (Division for Heart Disease and Stroke Prevention), Food and Drug Administration (Center for Food Safety and Applied Nutrition), Health Canada (Health Products and Food Branch), National Institutes of Health (National Heart, Lung, and Blood Institute; National Institute of Diabetes and Digestive and Kidney Diseases; and Office of Dietary Supplements), Public Health Agency of Canada (Centre for Surveillance and Applied Research), and U.S. Department of Agriculture (Food and Nutrition Service). This activity was also supported in part by the National Academy of Sciences’ W.K. Kellogg Foundation Fund and the National Academy of Medicine’s Kellogg Health of the Public Fund. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.
International Standard Book Number-13: 978-0-309-48834-1
International Standard Book Number-10: 0-309-48834-6
Digital Object Identifier: https://doi.org/10.17226/25353
Library of Congress Control Number: 2019940942
Additional copies of this publication are available from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; http://www.nap.edu.
Copyright 2019 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America
Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2019. Dietary Reference Intakes for sodium and potassium. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/25353.
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president.
The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. C. D. Mote, Jr., is president.
The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president.
The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine.
Learn more about the National Academies of Sciences, Engineering, and Medicine at www.nationalacademies.org.
Consensus Study Reports published by the National Academies of Sciences, Engineering, and Medicine document the evidence-based consensus on the study’s statement of task by an authoring committee of experts. Reports typically include findings, conclusions, and recommendations based on information gathered by the committee and the committee’s deliberations. Each report has been subjected to a rigorous and independent peer-review process and it represents the position of the National Academies on the statement of task.
Proceedings published by the National Academies of Sciences, Engineering, and Medicine chronicle the presentations and discussions at a workshop, symposium, or other event convened by the National Academies. The statements and opinions contained in proceedings are those of the participants and are not endorsed by other participants, the planning committee, or the National Academies.
For information about other products and activities of the National Academies, please visit www.nationalacademies.org/about/whatwedo.
COMMITTEE TO REVIEW THE DIETARY REFERENCE INTAKES FOR SODIUM AND POTASSIUM
VIRGINIA A. STALLINGS (Chair), Professor of Pediatrics, University of Pennsylvania Perelman School of Medicine, Director, Nutrition Center, Jean A. Cortner Endowed Chair in Gastroenterology and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, PA
CHERYL A. M. ANDERSON, Associate Professor, Department of Family and Preventive Medicine, University of California, San Diego, San Diego, CA (until September 2018)
PATSY M. BRANNON, Visiting Professor, Division of Nutritional Sciences, Cornell University, Ithaca, NY
ALICIA CARRIQUIRY, Distinguished Professor, Liberal Arts and Sciences, Professor of Statistics, Iowa State University, Ames, IA
WEIHSUEH A. CHIU, Professor, Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX
NANCY R. COOK, Professor, Division of Preventive Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
ERIC A. DECKER, Professor, Department Head, Department of Food Science, University of Massachusetts Amherst, Amherst, MA
JIANG HE, Joseph S. Copes Chair and Professor, Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA
JOACHIM H. IX, Professor and Chief, Division of Nephrology-Hypertension, University of California, San Diego, School of Medicine, San Diego, CA
ALICE H. LICHTENSTEIN, Gershoff Professor of Nutrition Science and Policy, Director and Senior Scientist, Cardiovascular Nutrition Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA
JOSEPH V. RODRICKS, Principal, Ramboll Environ, Arlington, VA
JANET A. TOOZE, Professor, Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, NC
GEORGE A. WELLS, Professor, Department of Epidemiology and Community Medicine, Director, Cardiovascular Research Methods Centre, University of Ottawa Heart Institute, Ottawa, Ontario, CA
ELIZABETH A. YETLEY, Senior Nutrition Research Scientist (Retired), Office of Dietary Supplements, National Institutes of Health, Bethesda, MD
MEGHAN HARRISON, Study Director
MARIA ORIA, Senior Program Officer
ANNA BURY, Research Associate (until August 2018)
ALICE VOROSMARTI, Research Associate (from August 2018)
MEREDITH YOUNG, Senior Program Assistant
ANN L. YAKTINE, Director, Food and Nutrition Board
EMILY A. CALLAHAN, Science Writer
MEI CHUNG, Associate Professor, Public Health and Community Medicine, Tufts University, Boston, MA
PAUL WHELTON, Clinical Professor, Show Chwan Health System Endowed Chair in Global Public Health, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA
This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.
We thank the following individuals for their review of this report:
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by EILEEN T. KENNEDY, Tufts University, and CATHERINE E. WOTEKI, Iowa State University. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.
As essential nutrients, sodium and potassium contribute to the fundamental physiology of human health. In the clinical setting, these are frequently measured blood electrolytes. Yet, blood electrolyte concentrations are rarely influenced by typical dietary intake in healthy individuals, as the kidney and hormone systems carefully regulate blood values. However, the sodium and potassium intake story is more dynamic in the public health setting. Evidence suggests that sodium and potassium intakes influence current and longer-term population health in children and adults mostly through complex and not fully understood mechanisms between dietary intake and blood pressure and cardiovascular health status. Based on a 2017 report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, 50 percent of men and 44 percent of women ages 45–54 years have clinically significant hypertension, and the prevalence increases with age. This information—such high prevalence of hypertension beginning early in adult life—was a surprise to me. Cardiovascular disease, including diagnoses of cardiovascular disease risk factors such as prehypertension, hypertension, and abnormal blood lipids, is common, and a majority of adults in the United States has more than one cardiovascular disease risk factor. The public health importance of the relationships of sodium and potassium intakes and health is clear. Congress asked the Centers for Disease Control and Prevention (CDC) to undertake a review of the Dietary Reference Intakes (DRIs) for sodium. Given the interrelationship between sodium and potassium, it was determined that assessing both together would be prudent. CDC, together with
the Food and Drug Administration, Health Canada, the National Institutes of Health, the Public Health Agency of Canada, and the U.S. Department of Agriculture, sponsored this study. The National Academy of Sciences’ W.K. Kellogg Foundation Fund and the National Academy of Medicine’s Kellogg Health of the Public Fund provided additional financial support.
The committee was charged to review the available evidence and to update the current DRIs for sodium and potassium. In 2005, the evidence supported an Adequate Intake (AI) for both nutrients, and a Tolerable Upper Intake Level (UL) only for sodium. In addition, we were asked to consider adding, if relevant, sodium and potassium intake values to reduce the risk of chronic disease endpoints. Committee deliberations were guided by three sources: Effects of Dietary Sodium and Potassium Intake on Chronic Disease Outcomes and Related Risk Factors, an Agency for Healthcare Research and Quality (AHRQ) systematic review of the evidence commissioned to be used by this committee; Guiding Principles for Developing Dietary Reference Intakes Based on Chronic Disease; and the DRI organizing framework. The 2011 Dietary Reference Intakes for Calcium and Vitamin D also served as a resource, as it was the most recent DRI report that considered the evidence of dietary intake and chronic disease indicators to make recommendations.
In addition to these reports, the committee gained insight from expert testimony, additional comprehensive literature searches as needed to ascertain the state of the science on specific questions, and committee expertise and deliberation. Our committee members represented key disciplines and skill sets needed for this work; they not only dedicated significant time and effort, but also created a collaborative environment of learning, lively debate, and commitment to a thorough review prior to making decisions. Implementing the new DRI concept of dietary intake recommendations of reduce the risk of chronic disease was a responsibility the committee embraced. This report provides the first DRI based on chronic disease recommendations and documents both the evidence and the deliberative process to inform future DRI committees considering chronic disease recommendations.
Research into cardiovascular disease, hypertension, and diet has been among the priority areas for decades, yet numerous knowledge gaps persist. Additional research is essential to inform the next review of how sodium and potassium dietary intakes affect health across the DRI life stages. High-quality evidence to guide dietary recommendations to support the health of the youngest children, oldest adults, and pregnant and lactating women in the United States and Canada is also sparse.
Understanding the food and beverage sources of dietary sodium and potassium was not examined in detail, nor were the complex interactions of nonprocessed and processed food availability, cultural and personal taste
preference, and behavioral components of food choice. However, some common misconceptions came to light. Most of the salt in our modern diet pattern comes from commercially prepared food and beverage components and products, not from salt added by consumers cooking at home or from salt added by the consumer at the time of consumption. When considering sodium sources for the population over 2 years of age, most common sodium sources are breads, pizza, and cured meats and poultry. For children specifically, cheese is the top food category source of sodium, followed by cured meats and poultry, and then mixed dishes including pizza. For the desired public health benefit of reduced sodium intake to be achieved, more attention must be paid by industry to reducing sodium in the food supply and by consumers who have the needed sodium content information and an understanding of how to make health-inspired food choices. Dietary potassium intake is related to specific vegetable or fruit intakes—and then remember that as a population, our vegetable and fruit intake rarely meets the recommended servings per day. When you consider all ages, higher dietary sources of potassium are from milk, white potatoes, and fruit. Coffee is the top source of potassium in people in the 51 years of age and older group in the United States.
The committee thoroughly considered the totality of evidence available and used processes now established for DRI review and revisions. Our DRI report provides a sodium intake level as an AI, and with sodium, the report establishes the first Chronic Disease Risk Reduction Intake (CDRR) level. Our report provides a potassium intake level as an AI, and the committee determined there was insufficient evidence to establish a CDRR for potassium. In addition, using the evolving toxicological risk assessment approach, the committee found there was insufficient evidence of risk of excess sodium or potassium intake within the healthy populations to establish a UL for either nutrient.
Many other people contributed to this report. Two consultants, Mei Chung and Paul Whelton, provided their advice and guidance to the committee. Emily Callahan provided editorial assistance with the report. The National Academies Research Center, particularly Jorge Mendoza-Torres, provided support and assistance with the design and execution of the committee’s scoping literature searches. The committee was also assisted by Jennifer Garner, who was an intern with the Food and Nutrition Board in Spring 2018. The committee would also like to thank both CDC and Health Canada for providing intake distribution tables and other information requested by the committee.
Lastly, as chair, I express my sincere appreciation to each committee member and to each member of our National Academies staff, including Meghan Harrison and Maria Oria, for their extraordinary commitment to the project and to our shared goal to complete this complex task in a way
that serves the public’s health and health care in general. We worked well together to prepare a report that will contribute to actively improving the health of children and adults.
Virginia A. Stallings, Chair
Committee to Review the Dietary Reference Intakes for Sodium and Potassium
Study Overview and Statement of Task
Design and Approach to the Study
2 APPLYING THE GUIDING PRINCIPLES REPORT
The Committee’s Interpretation of the Guiding Principles Report
The Chronic Disease Risk Reduction Intake in Context of the Other DRI Categories
3 METHODOLOGICAL CONSIDERATIONS
Relevant Biological Roles of Potassium and Sodium
Methods for Estimating Potassium and Sodium Intake
Interactions of Potassium and Sodium
4 POTASSIUM: DIETARY REFERENCE INTAKES FOR ADEQUACY
Potassium Adequate Intake Levels Established in the 2005 DRI Report
Review of Potential Indicators of Potassium Adequacy
Dietary Reference Intakes of Potassium Adequacy
Summary of Updated Potassium Adequate Intake Values
5 POTASSIUM: DIETARY REFERENCE INTAKES FOR TOXICITY
Potassium Tolerable Upper Intake Levels in the 2005 DRI Report
Review of Potential Indicators of Toxicological Adverse Effects of Excessive Potassium Intake
The Committee’s Conclusion Regarding the Tolerable Upper Intake Level for Potassium
6 POTASSIUM: DIETARY REFERENCE INTAKES BASED ON CHRONIC DISEASE
Review of Chronic Disease Indicators
The Committee’s Conclusion Regarding Chronic Disease Risk Reduction Intakes for Potassium
7 POTASSIUM DIETARY REFERENCE INTAKES: RISK CHARACTERIZATION AND SPECIAL CONSIDERATIONS FOR PUBLIC HEALTH
Risk Characterization Based on Potassium Intake Levels in the U.S. and Canadian Populations
Sources of Potassium in the Diet
Public Health Implications and Special Considerations
8 SODIUM: DIETARY REFERENCE INTAKES FOR ADEQUACY
Sodium Adequate Intake Levels Established in the 2005 DRI Report
Review of Potential Indicators of Sodium Adequacy
Additional Evidence Considered: Potential Harmful Health Effects of Low Sodium Intakes
Dietary Reference Intakes of Sodium Adequacy
Summary of Updated Sodium Adequate Intake Values
9 SODIUM: DIETARY REFERENCE INTAKES FOR TOXICITY
Sodium Tolerable Upper Intake Levels Established in the 2005 DRI Report
Review of Potential Indicators of Toxicological Adverse Effects of Excessive Sodium Intake
The Committee’s Conclusion Regarding the Tolerable Upper Intake Levels for Sodium
10 SODIUM: DIETARY REFERENCE INTAKES BASED ON CHRONIC DISEASE
Review and Selection of Chronic Disease Indicators
Assessment of Intake–Response for Chronic Disease Indicators
Chronic Disease Risk Reduction Intakes for Sodium
11 SODIUM DIETARY REFERENCE INTAKES: RISK CHARACTERIZATION AND SPECIAL CONSIDERATIONS FOR PUBLIC HEALTH
Risk Characterization Based on Sodium Intake Levels in the U.S. and Canadian Populations
The Role of Sodium in the Food Supply and Sources of Sodium in the Diet
Public Health Implications and Special Considerations
12 KNOWLEDGE GAPS AND FUTURE DIRECTIONS
Knowledge Gaps and Research Needs
Opportunities to Enhance the DRI Process
C Committee’s Assessment of the Agency for Healthcare Research and Quality Systematic Review
D Indicators Not Relevant for Establishing Dietary Reference Intake Values
E Supplemental Literature Searches
F Estimates of Potassium and Sodium Intakes from Breast Milk and Complementary Foods
G Sources of Evidence for Potassium and Sodium Intake Distributions
H Supplemental Risk Characterization Figures
I Committee Member Biographical Sketches