Dietary reference intakes and their development

Dietary reference intakes (DRIs) are an important scientific underpinning to work related to nutritional health and safety at both the population and individual levels. Canada and the United States have collaborated since the mid-1990s to provide joint support for developing the DRI values. The independent National Academies of Science, Engineering, and Medicine (NASEM) oversees this development process.

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DRI general overview

DRIs are a comprehensive set of nutrient reference values used by professionals working in the field of nutrition and health.

There is a set of different values for each nutrient, each with different uses, depending on the application. Most nutrients have several DRI values.

Each type of DRI refers to the average daily nutrient intake for the general population over time.

Definitions of the different DRIs provide further details about each of these values.

Values related to meeting nutritional requirements are:

  • estimated average requirement (EAR)
  • estimated energy requirement (EER)
  • recommended dietary allowance (RDA)
  • adequate intake (AI)

The value for preventing excessive intakes is the:

  • tolerable upper intake level (UL)

The values for reducing risk of chronic disease are the:

  • chronic disease risk reduction intake (CDRR)
  • acceptable macronutrient distribution range (AMDR)

The DRI values provide the scientific basis for nutrition professionals, governments and non-governmental organizations to carry out activities such as:

  • developing nutrition labels
  • developing dietary guidelines and food guides
  • ensuring foods and supplements contain safe levels of nutrients
  • creating patient and consumer counseling and educational programs
  • assessing nutrient intakes and monitoring the nutritional health of the population

It's important that DRIs remain up-to-date, to support the health of people living in Canada.

The DRI development process

The governments of Canada and the United States jointly provide the funding to the National Academies of Science, Engineering, and Medicine (NASEM) to develop DRIs, but don't participate in the review process.

NASEM is an organization that provides independent scientific advice. It has no institutional self-interest in any reports it produces, beyond maintaining its reputation for independence and sound scientific reports.

For each nutrient review, NASEM appoints a committee of scientific experts from both Canada and the United States. NASEM carefully screens committee members for conflicts of interest. The expert committee then:

  • reviews the latest science, using systematic reviews of the scientific literature and other relevant studies
  • selects the health outcomes that will inform the DRIs
    • The different types of DRI values are based on different types of health outcomes. The ones that have the strongest and most relevant evidence are used.
  • establishes the DRI values
  • describes special considerations and public health implications
  • identifies knowledge gaps and areas where further research is needed

NASEM reports undergo independent peer review before publication to help ensure scientific quality and objectivity.

NASEM publishes the work of the expert committees in the dietary reference intake reports.

Why Canada collaborates with the United States

The science and research behind nutrients, foods and their impact on health is expanding rapidly in scope and complexity. Links with the U.S. allow us to:

  • coordinate discussions on priorities and future work needed
  • access an expanded base of specialized scientific expertise
  • coordinate and efficiently use the funding and resources available

International trade agreements also make harmonizing standards based on science useful for trade-related matters such as food labelling.

Chronology of nutrient standards and DRI development in Canada

Year(s) Start of nutrient standards
1939 Canadian Council on Nutrition publishes first dietary standards in Canada.
1941 First edition of the Recommended Dietary Allowances (RDAs) published in the United States.
1942 Canadian Council on Nutrition adopts RDAs for the sake of consistency.

Canadian Council on Nutrition advises discontinuing use of RDAs in Canada.

A new Canadian standard is released.


Canadian standards periodically updated and released, based on cumulative scientific data.

Term "recommended nutrient intakes" is used for the first time in the 1983 version of Canadian standards.

1989 10th edition of the RDAs published in the United States.
1990 Health Canada (formerly Health and Welfare Canada) publishes revised recommended nutrient intakes (RNIs).
Year(s) DRI process begins

The Institute of Medicine (IOM), later integrated into the National Academy of Sciences, Engineering, and Medicine (NASEM), holds symposium and public hearing entitled "Should the Recommended Dietary Allowances Be Revised?"

IOM proposes changes to the process of developing the RDAs based on comments and suggestions from this meeting.

1994 IOM publishes the concept paper "How Should the Recommended Dietary Allowances Be Revised?" IOM holds workshops at which experts discuss development of nutrient-based reference values.
1995 (April)

Multi-sector Canadian symposium reviews pros and cons of harmonizing dietary standards with those of United States. Symposium reaches consensus in support of harmonization.

Health Canada approaches IOM to collaborate on development of harmonized nutrient-based recommendations.

1995 (December)

IOM establishes standing committee on the scientific evaluation of dietary reference intakes to oversee and conduct the project to develop DRIs.

Project structure includes:

  • nutrient expert panels made up of Canadian and U.S. scientists
  • 2 overarching subcommittees

Subcommittee on upper reference levels of nutrients established.

First nutrient panel, on calcium and related nutrients, established.

1997 IOM issues first nutrient report on calcium and related nutrients.
1998 Subcommittee on interpretation and uses of dietary reference intakes established.

Reports released on:

  • other nutrient groups: B vitamins; antioxidants; micronutrients; energy and macronutrients; electrolytes and water
  • applications in assessment
  • applications in planning
  • risk assessment model for developing ULs
  • definition and plan for review of antioxidants
  • definition of dietary fibre
  • guiding principles for nutrition labelling and fortification
2006 Summary of the dietary reference intakes series, "DRIs: The Essential Guide to Nutrient Requirements" published.

U.S. and Canadian governments support a public workshop entitled "The Development of DRIs 1994-2004: Lessons Learned and New Challenges".

The workshop identified issues important for enhancing the process of DRI development into the future, as well as the application of the values.


Based on the availability of new and relevant scientific research, U.S. and Canadian governments prioritize vitamin D and calcium to undergo a new DRI review.

This DRI review is the first to incorporate systematic evidence-based review of the literature.

2011 IOM publishes report containing updated DRI values for calcium and vitamin D

The U.S. and Canadian governments establish an open nutrient nomination process to help in planning and prioritizing new DRI reviews of nutrients. The process was open to government and non-governmental organizations.

26 nominations on 16 nutrients were received.


4 nominated nutrients prioritized for further consideration: omega-3 fatty acids, sodium, magnesium, and vitamin E.

The need to resolve issues related to use of chronic disease endpoints in setting DRI values is identified.

2015 IOM is renamed as the National Academy of Medicine and integrated into the renamed National Academies of Sciences, Engineering, and Medicine (NASEM).
2015 - 2016

Canadian and U.S. governments hold a workshop entitled "Options for Consideration of Chronic Disease Endpoints for Dietary Reference Intakes (DRIs)".

A multidisciplinary expert working group sponsored by Canadian and U.S. governments builds on the workshop. It develops a report that presents options to address conceptual and methodological challenges related to this topic: Options for basing Dietary Reference Intakes (DRIs) on chronic disease endpoints: Report from a joint U.S./Canadian-sponsored working group.

2017 (August) NASEM publishes report on Guiding Principles for Developing Dietary Reference Intakes Based on Chronic Disease.

U.S. and Canadian governments prioritize sodium and potassium to undergo a new DRI review.

This DRI review is the first to incorporate the Guiding Principles for Developing Dietary Reference Intakes Based on Chronic Disease.

2019 NASEM publishes report containing updated DRI values for sodium and potassium.
2021 U.S. and Canadian governments prioritize energy and macronutrients to undergo a new DRI review.
2022 The NASEM Standing Committee to Review the DRI Framework is put into place to facilitate a consistent approach for reviewing and setting DRIs.
2023 NASEM publishes report with updated DRI values for energy.

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