Dietary Reference Intake
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the Institute of Medicine (IOM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Recommended Dietary Allowances (RDAs, see below). The DRI values differ from those used in nutrition labeling in the U.S. and Canada, which uses Reference Daily Intakes (RDIs) and Daily Values (%DV) based on outdated RDAs from 1968.
The DRI provides several different types of reference value:
- Estimated Average Requirements (EAR), expected to satisfy the needs of 50% of the people in that age group based on a review of the scientific literature.
- Recommended Dietary Allowances (RDA), the daily dietary intake level of a nutrient considered sufficient by the Food and Nutrition Board of the Institute of Medicine to meet the requirements of 97.5% of healthy individuals in each life-stage and sex group. The definition implies that the intake level would cause a harmful nutrient deficiency in just 2.5%. It is calculated based on the EAR and is usually approximately 20% higher than the EAR (See Calculating the RDA).
- Adequate Intake (AI), where no RDA has been established, but the amount established is somewhat less firmly believed to be adequate for everyone in the demographic group.
- Tolerable upper intake levels (UL), to caution against excessive intake of nutrients (like vitamin A) that can be harmful in large amounts. This is the highest level of daily nutrient consumption that is considered to be safe for, and cause no side effects in, 97.5% of healthy individuals in each life-stage and sex group. The definition implies that the intake level would cause a harmful nutrient excess in just 2.5%. The European Food Safety Authority (EFSA) has also established ULs which do not always agree with U.S. ULs. For example, zinc UL is 40 mg in U.S. and 25 mg in EFSA.
- Acceptable Macronutrient Distribution Ranges (AMDR), a range of intake specified as a percentage of total energy intake. Used for sources of energy, such as fats and carbohydrates.
- Composition of diets for schools, prisons, hospitals or nursing homes
- Industries developing new food stuffs
- Healthcare policy makers and public health officials
The recommended dietary allowance (RDA) was developed during World War II by Lydia J. Roberts, Hazel Stiebeling, and Helen S. Mitchell, all part of a committee established by the United States National Academy of Sciences in order to investigate issues of nutrition that might "affect national defense".
The committee was renamed the Food and Nutrition Board in 1941, after which they began to deliberate on a set of recommendations of a standard daily allowance for each type of nutrient. The standards would be used for nutrition recommendations for the armed forces, for civilians, and for overseas population who might need food relief. Roberts, Stiebeling, and Mitchell surveyed all available data, created a tentative set of allowances for "energy and eight nutrients", and submitted them to experts for review (Nestle, 35).
The final set of guidelines, called RDAs for Recommended Dietary Allowances, were accepted in 1941. The allowances were meant to provide superior nutrition for civilians and military personnel, so they included a "margin of safety." Because of food rationing during the war, the food guides created by government agencies to direct citizens' nutritional intake also took food availability into account.
The Food and Nutrition Board subsequently revised the RDAs every five to ten years. In the early 1950s, United States Department of Agriculture nutritionists made a new set of guidelines that also included the number of servings of each food group in order to make it easier for people to receive their RDAs of each nutrient.
The DRI was introduced in 1997 in order to broaden the existing system of RDAs. DRIs were published over the period 1998 to 2001. In 2010, revised DRIs were published for calcium and vitamin D.
The current DRI values may differ from those used in nutrition labeling in the U.S. and Canada, which uses Reference Daily Intakes (RDIs) and Daily Values (%DV) based on RDAs from 1968. Example of DRIs not matching DVs: the U.S. RDA for vitamin B12 is 2.4 µg/day whereas 100% DV is 6.0 µg/day.
Vitamins and minerals
EARs, RDA/AIs and ULs for an average healthy 44-year-old male are shown below. Amounts and "ND" status for other age and gender groups, pregnant women, lactating women, and breastfeeding infants may be much different.
• "NE": EARs have not yet been established or not yet evaluated.
• "ND": ULs could not be determined, and it is recommended that intake from these nutrients be from food only, to prevent adverse effects.
|Nutrient||EAR||RDA/AI||UL||Unit||Top Sources in Common Measures, USDA|
|Vitamin A||625||900||3000||µg||turkey and chicken giblets, liver, red capsicum, carrots, pumpkin, sweet potato|
|Vitamin C||75||90||2000||mg||guavas, oranges, grapefruits, frozen peaches, [lower-roman 1] bell peppers|
|Vitamin D||10||15||100||µg||fortified cereals, mushrooms, yeast, sockeye salmon, swordfish, rainbow trout, sardines, cod liver oil (also fortified foods and beverages)|
|Vitamin K||NE||120||ND||µg||kale, collards, spinach, broccoli, brussel sprouts, asparagus, prunes, green peas|
|Vitamin B6||1.1||1.3||100||mg||fortified cereals, chickpeas, sockeye salmon|
|α-tocopherol (Vitamin E)||12||15||1000||mg||fortified cereals, tomato paste, sunflower seeds|
|Biotin (B7)||NE||30||ND||µg||whole grains, almonds, peanuts, beef liver, egg yolk, salmon|
|Calcium||800||1000||2500||mg||fortified cereals, collards, almonds, condensed cow's milk, cheese, figs, yogurt, milk|
|Chromium||NE||35||ND||µg||broccoli, turkey ham, dried peaches, tuna, grape juice|
|Choline||NE||550||3500||mg||egg yolk, meats, lecithin, beef liver, condensed milk, quinoa, salmon, cod|
|Copper||700||900||10000||µg||sesame seeds, sunflower seeds, oysters, lobster, cashews, dark chocolate, pearled barley, Brazil nuts, walnuts, peanuts, yellow peas, chickpeas|
|Cyanocobalamin (B12)||2.0||2.4||ND||µg||fortified cereals, turkey, clams, beef, egg yolk, sardines, tuna fish, mackerel|
|Fluoride||NE||4||10||mg||public drinking water, where fluoridation is performed or natural fluorides are present|
|Folate (B9)||320||400||1000||µg||leafy greens, enriched white rice, fortified cereals, enriched cornmeal|
|Iodine||95||150||1100||µg||iodized salt, kelp, cod|
|Iron||6||8||45||mg||cocoa powder, cashew nuts, white beans, turkey, dark chocolate|
|Magnesium||330||400||350[lower-roman 2]||mg||buckwheat flour, rolled oats, spinach, almonds, dark chocolate, bulgur, quinoa|
|Manganese||NE||2.3||11||mg||oat bran, whole grain wheat flour, bulgur, rolled oats, brown rice, parboiled rice, dark chocolate|
|Molybdenum||34||45||2000||µg||legumes, grain products, nuts and seeds|
|Niacin (B3)||12||16||35||mg||fortified cereals, yellowfin tuna, sockeye salmon, chicken meat|
|Pantothenic acid (B5)||NE||5||ND||mg||fortified cereals, beef liver, shiitake mushrooms|
|Phosphorus||580||700||4000||mg||cornmeal, condensed milk, wheat flour, rolled oats, brown rice, bulgur, milk, meats|
|Potassium||NE||4700||ND||mg||potatoes, bananas, tomato paste, tomatoes, bell peppers, orange juice, beet greens, quinoa, rolled oats, bulgur, beans, peas, cashews, pistachio nuts|
|Riboflavin (B2)||1.1||1.3||ND||mg||almonds, sesame seeds, spaghetti, beef liver, turkey|
|Selenium||45||55||400||µg||Brazil nuts, rockfish, yellowfin tuna, beef, sardines, salmon, egg yolk, pearled barley, mackerel|
|Sodium||NE||1500||2300||mg||onion soup mix, miso, table salt, egg whites|
|Thiamin (B1)||1.0||1.2||ND||mg||fortified cereals, enriched wheat flour, breadcrumbs|
|Zinc||9.4||11||40||mg||nuts, oysters, fortified cereals, beef, baked beans, oatmeal|
EAR: Estimated Average Requirements; RDA: Recommended Dietary Allowances; AI: Adequate Intake; UL: Tolerable upper intake levels.
- Vitamin C is added to frozen peaches to prevent darkening. Raw peaches and peaches preserved in syrup do not have a high vitamin C content.
- The UL for magnesium represents extra intake from dietary supplements. High doses of magnesium from dietary supplements or medications often result in diarrhea that can be accompanied by nausea and abdominal cramping. There is no evidence of adverse effects from the consumption of naturally occurring magnesium in foods.
It is also recommended that the following substances not be added to food or dietary supplements. Research has been conducted into adverse effects, but was not conclusive in many cases:
|Substance||RDA/AI||UL||units per day|
RDA/AI is shown below for males and females aged 40–50 years.
|Substance||Amount (males)||Amount (females)||Top Sources in Common Measures|
|Water[lower-roman 1]||3.7 L/day||2.7 L/day||water, watermelon, iceberg lettuce|
|Carbohydrates||130 g/day||130 g/day||milk, grains, fruits, vegetables|
|Protein[lower-roman 2]||56 g/day||46 g/day||meats, fish, legumes (pulses and lentils), nuts, milk, cheeses, eggs|
|Fiber||38 g/day||25 g/day||barley, bulgur, rolled oats, legumes, nuts, beans, apples,|
|Fat||20–35% of calories||oils, butter, lard, nuts, seeds, fatty meat cuts, egg yolk, cheeses|
|Linoleic acid, an omega-6 fatty acid (polyunsaturated)||17 g/day||12 g/day||sunflower seeds, sunflower oil, safflower oil,|
|alpha-Linolenic acid, an omega-3 fatty acid (polyunsaturated)||1.6 g/day||1.1 g/day||Linseed oil (Flax seed), salmon, sardines|
|Cholesterol||300 milligrams(mg)||chicken giblets, turkey giblets, beef liver, egg yolk|
|Trans fatty acids||As low as possible|
|Saturated fatty acids||As low as possible while consuming a nutritionally adequate diet ||coconut meat, coconut oil, lard, cheeses, butter, chocolate, egg yolk|
|Added sugar||No more than 25% of calories||foods that taste sweet but are not found in nature, such as sweets, cookies, cakes, jams, energy drinks, soda drinks, many processed foods|
- Includes water from food, beverages, and drinking water.
- Based on 0.8 g/kg of body weight.
Calculating the RDA
The equations used to calculate the RDA are as follows:
If data about variability in requirements are insufficient to calculate an SD, a coefficient of variation (CV) for the EAR of 10 percent is assumed, unless available data indicate a greater variation in requirements. If 10 percent is assumed to be the CV, then twice that amount when added to the EAR is defined as equal to the RDA. The resulting equation for the RDA is then
This level of intake statistically represents 97.5 percent of the requirements of the population."
Standard of evidence
In September 2007, the Institute of Medicine held a workshop entitled “The Development of DRIs 1994–2004: Lessons Learned and New Challenges.” At that meeting, several speakers stated that the current Dietary Recommended Intakes (DRI’s) were largely based upon the very lowest rank in the quality of evidence pyramid, that is, opinion, rather than the highest level – randomized controlled clinical trials. Speakers called for a higher standard of evidence to be utilized when making dietary recommendations.
|Nutrient||Percent of U.S. population ages 2+ meeting EAR in 2004|
|% calories from total fat <= 35%||59.4%|
|% calories from saturated fat < 10%||40.8%|
|Cholesterol intake < 300 mg||68.4%|
|Sodium intake <= 2,300 mg||29.9%|
- Acceptable daily intake – upper limit on intake (United Kingdom)
- Canada's Food Guide
- Dietary Reference Values – recommended dietary requirements (United Kingdom)
- Dietary mineral
- Essential amino acid
- Essential fatty acid
- Essential nutrient
- Food composition
- Food guide pyramid
- Healthy diet
- Reference Daily Intake
- Reference Intakes – a system of nutrient labeling used in Europe
- Vitamin poisoning
- "A Consumer's Guide to the DRIs (Dietary Reference Intakes)". Health Canada. 2010-11-29. Retrieved 2012-08-17.
- Dietary Reference Intakes: Applications in Dietary Planning. National Academy Press. 2003. p. 51. ISBN 978-0-309-08853-4.
- Tolerable Upper Intake Levels For Vitamins And Minerals (PDF), European Food Safety Authority, 2006
- Harper AE (November 2003). "Contributions of women scientists in the U.S. to the development of Recommended Dietary Allowances". J. Nutr. 133 (11): 3698–702. PMID 14608098.
- Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals (PDF), Food and Nutrition Board, Institute of Medicine, National Academies, 2004, retrieved 2009-06-09
- Dietary Reference Intakes (DRIs): Tolerable Upper Intake Levels, Vitamins., Food and Nutrition Board, Institute of Medicine, National Academies, 1997
- "Search by selected nutrient, USDA National Nutrient Database for Standard Reference, SR28". 2016. Retrieved 19 May 2016.
- P. Kendall (2013). "Freezing Fruits". Colorado State University Extension. Fact Sheet No. 9.331. Retrieved 2014-10-02.
- Dietary Reference Intakes for Calcium and Vitamin D. Washington DC: National Academy Press. 2011. ISBN 0-309-16394-3. Lay summary – Institute of Medicine.
..., The IOM finds that the evidence supports a role for vitamin D and calcium in bone health but not in other health conditions. Further, emerging evidence indicates that too much of these nutrients may be harmful, challenging the concept that “more is better“.
- "Biotin". Micronutrient Information Center, Linus Pauling Institute, Oregon State University.
- "Chromium". Micronutrient Information Center, Linus Pauling Institute, Oregon State University.
- "Molybdenum". Micronutrient Information Center, Linus Pauling Institute, Oregon State University.
- "14. Appendix F: Calculate the Percent Daily Value for the Appropriate Nutrients". Guidance for Industry: A Food Labeling Guide. Office of Nutrition, Labeling, and Dietary Supplements, Center for Food Safety and Applied Nutrition, Food and Drug Administration, U.S. Department of Health and Human Services. October 2009.
- Panel on Micronutrients 2001
- The Development of DRIs 1994–2004: Lessons Learned and New Challenges. Workshop Summary, November 30, 2007
- "California". Community Nutrition Mapping Project. USDA Agricultural Research Service. "All U.S." column. Retrieved 6 Nov 2014.
- Nestle, Marion (2002). Food Politics. Berkeley: University of California Press. ISBN 0-520-22465-5.
- Panel on Micronutrients, Subcommittees on Upper Reference Levels of Nutrients and of Interpretation and Use of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (2001). Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington DC: National Academy Press. ISBN 0-309-07279-4.