Understanding Dietary Reference Intakes
University of Hawai‘i at Mānoa Food Science and Human Nutrition Program and Human Nutrition Program
(DRI) are the recommendation levels for specific nutrients and consist of a number of different types of recommendations. This DRI system is used in both the United States and Canada.
Dietary Reference Intakes: A Brief Overview
“Dietary Reference Intakes” (DRI) is an umbrella term for four reference values:
- (EAR)
- (RDA)
- (AI)
- (UL)
The DRIs are not minimum or maximum nutritional requirements and are not intended to fit everybody. They are to be used as guides only for the majority of the healthy population[1].
DRIs are important not only to help the average person determine whether their intake of a particular is adequate, they are also used by health-care professionals and policy makers to determine nutritional recommendations for special groups of people who may need help reaching nutritional goals. This includes people who are participating in programs such as the Special Supplemental Food Program for Women, Infants, and Children. The DRI is not appropriate for people who are ill or malnourished, even if they were healthy previously.
Determining Dietary Reference Intakes
Each DRI value is derived in a different way. See below for an explanation of how each is determined:
- Estimated Average Requirements. The EAR for a nutrient is determined by a committee of experts who review the scientific literature to determine a value that meets the requirements of 50 percent of people in their target group within a given life stage and for a particular sex. The requirements of half of the group will fall below the EAR and the other half will be above it. It is important to note that, for each nutrient, a specific bodily function is chosen as the criterion on which to base the EAR. For example, the EAR for calcium is set using a criterion of maximizing bone health. Thus, the EAR for calcium is set at a point that will meet the needs, with respect to bone health, of half of the population. EAR values become the scientific foundation upon which RDA values are set.
- Recommended Daily Allowances. Once the EAR of a nutrient has been established, the RDA can be mathematically determined. While the EAR is set at a point that meets the needs of half the population, RDA values are set to meet the needs of the vast majority (97 to 98 percent) of the target healthy population. It is important to note that RDAs are not the same thing as individual nutritional requirements. The actual nutrient needs of a given individual will be different than the RDA. However, since we know that 97 to 98 percent of the population’s needs are met by the RDA, we can assume that if a person is consuming the RDA of a given nutrient, they are most likely meeting their nutritional need for that nutrient. The important thing to remember is that the RDA is meant as a recommendation and meeting the RDA means it is very likely that you are meeting your actual requirement for that nutrient.
Understanding the Difference
There is a distinct difference between a requirement and a recommendation. For instance, the DRI for is a recommended 600 international units each day. However, in order to find out your true personal requirements for vitamin D, a blood test is necessary. The blood test will provide an accurate reading from which a medical professional can gauge your required daily vitamin D amounts. This may be considerably more or less than the DRI, depending on what your level actually is.
- . AIs are created for nutrients when there is insufficient consistent scientific evidence to set an EAR for the entire population. As with RDAs, AIs can be used as nutrient-intake goals for a given nutrient. For example, there has not been sufficient scientific research into the particular nutritional requirements for infants. Consequently, all of the DRI values for infants are AIs derived from nutrient values in human breast milk. For older babies and children, AI values are derived from human milk coupled with data on adults. The AI is meant for a healthy target group and is not meant to be sufficient for certain at-risk groups, such as premature infants.
- Tolerable Upper Intake Levels. The UL was established to help distinguish healthful and harmful nutrient intakes. Developed in part as a response to the growing usage of dietary supplements, ULs indicate the highest level of continuous intake of a particular nutrient that may be taken without causing health problems. When a nutrient does not have any known issue if taken in excessive doses, it is not assigned a UL. However, even when a nutrient does not have a UL it is not necessarily safe to consume in large amounts.
Figure 12.1 DRI Graph
This graph illustrates the risks of nutrient inadequacy and nutrient excess as we move from a low intake of a nutrient to a high intake. Starting on the left side of the graph, you can see that when you have a very low intake of a nutrient, your risk of nutrient deficiency is high. As your nutrient intake increases, the chances that you will be deficient in that nutrient decrease. The point at which 50 percent of the population meets their nutrient need is the EAR, and the point at which 97 to 98 percent of the population meets their needs is the RDA. The UL is the highest level at which you can consume a nutrient without it being too much—as nutrient intake increases beyond the UL, the risk of health problems resulting from that nutrient increases.
Source: Dietary Reference Intakes Tables and Application. The National Academies of Science, Engineering, and Medicine. Health and Medicine Division. http://nationalacademies.org/HMD/Activities/Nutrition/SummaryDRIs/DRI-Tables.aspx. Accessed November 22, 2017.
The (AMDR) is the calculated range of how much energy from , fats, and is recommended for a healthy diet adequate of the essential nutrients and is associated with a reduced risk of chronic disease. The ranges listed in Table 12.1 “Acceptable Macronutrient Distribution Ranges (AMDR) For Various Age Groups” allows individuals to personalize their diets taking into consideration that different subgroups in a population often require different requirements. The DRI committee recommends using the midpoint of the AMDRs as an approach to focus on moderation[2].
Table 12.1 Acceptable Macronutrient Distribution Ranges (AMDR) For Various Age Groups
| Age Group | Protein (%) | Carbohydrates (%) | Fat (%) |
| Children (1–3) | 5–20 | 45–65 | 30–40 |
| Children and Adolescents (4–18) | 10–30 | 45–65 | 25–35 |
| Adults (>19) | 10–35 | 45–65 | 20–35 |
Source: Food and Nutrition Board of the Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. http://www.nationalacademies.org/hmd/~/media/Files/Activity%20Files/Nutrition/DRI-Tables/8_Macronutrient%20Summary.pdf?la=en. Published 2002. Accessed November 22, 2017.
Tips for Using the Dietary Reference Intakes to Plan Your Diet
You can use the DRIs to help assess and plan your diet. Keep in mind when evaluating your nutritional intake that the values established have been devised with an ample safety margin and should be used as guidance for optimal intakes. Also, the values are meant to assess and plan average intake over time; that is, you don’t need to meet these recommendations every single day—meeting them on average over several days is sufficient.
Learning Activities
Technology Note: The second edition of the Human Nutrition Open Educational Resource (OER) textbook features interactive learning activities. These activities are available in the web-based textbook and not available in the downloadable versions (EPUB, Digital PDF, Print_PDF, or Open Document).
Learning activities may be used across various mobile devices, however, for the best user experience it is strongly recommended that users complete these activities using a desktop or laptop computer and in Google Chrome.
- Deng S, West BJ, Jensen CJ. (2010). A Quantitative Comparison of Phytochemical Components in Global Noni Fruits and Their Commercial Products. Food Chemistry, 122(1), 267–70. http://www.sciencedirect.com/science/article/pii/S0308814610001111. Accessed December 4, 2017. ↵
- Dietary Reference Intakes Tables and Application. The National Academies of Science, Engineering, and Medicine. Health and Medicine Division. http://nationalacademies.org/HMD/Activities/Nutrition/SummaryDRIs/DRI-Tables.aspx. Accessed November 22, 2017. ↵
A set of values for the intake of energy, nutrients, and food components that can be used for planning and assessing the diets of healthy individuals in the United States and Canada.
Nutrient intakes that are estimated to meet the needs of 50% of the healthy individuals in specific gender and life-stage group.
Levels of intake of essential nutrients that, on the basis of scientific knowledge, are judged by the Food and Nutrition Board to be adequate to meet the known nutrient needs of almost all healthy people.
(Adequate Intake) The level of nutrient intake that should be used as a goal when no RDA exists. This value is an approximation of the nutrient intake that sustains health.
(Tolerable Upper Intake Level) The maximum daily nutrient intake levels that are likely to pose health risks to almost all individuals in a given gender and life-stage group.
A substance in food that can provide energy, contribute to body structure, and/or regulate body processes.
The sum of all processes involved in how organisms obtain nutrients, metabolize them, and use them to support all of life’s processes.
A fat-soluble vitamin that can be made in the body when there is exposure to sunlight and is needed for the absorption of calcium.
The level of nutrient intake that should be used as a goal when no RDA exists. This value is an approximation of the nutrient intake that sustains health.
(Acceptable Macronutrient Distribution Ranges) A range of intakes for carbohydrates, fat, and protein expressed as a percentage of total energy intake for normal healthy individuals.
A class of nutrients containing carbon, hydrogen, and oxygen atoms; most are commonly known as sugar, starches or dietary fibers.
A class of compounds composed of linked amino acids. They contain carbon, hydrogen, nitrogen, oxygen, and sometimes other atoms in specific configurations.