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 on food and dietary supplement products in the U.S. and Canada, which uses Reference Daily Intakes (RDIs) and Daily Values (%DV) which were based on outdated RDAs from 1968 but were updated as of 2016.
DRI provides several different types of reference values:
The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States, but values may differ.
DRIs are used by both the United States and Canada, and are intended for the general public and health professionals. Applications include:
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 2011, revised DRIs were published for calcium and vitamin D. None of the other DRIs have been revised since first published 1998 to 2001.
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.
|Nutrient||EAR||Highest RDA/AI||UL||Unit||Top common sources, 100 grams, U.S. Department of Agriculture (USDA)|
|Vitamin A||625||900||3000||µg||cod liver oil, liver, dehydrated red sweet peppers, veal, dehydrated carrots|
|Thiamin (B1)||1.0||1.2||ND||mg||fortified breakfast cereals, energy bars, vegetarian, and baby food products|
|Riboflavin (B2)||1.1||1.3||ND||mg||fortified food products, lamb liver, spirulina|
|Niacin (B3)||12||16||35||mg||fortified food products, baker's yeast, rice bran, instant coffee, fortified beverages|
|Pantothenic acid (B5)||NE||5||ND||mg||fortified food and beverage products, dried shiitake mushrooms, beef liver, rice bran|
|Vitamin B6||1.1||1.3||100||mg||fortified food and beverage products, rice bran, fortified margarines, ground sage|
|Biotin (B7)||NE||30||ND||µg||organ meats, eggs, fish, meat, seeds, nuts|
|Folate (B9)||320||400||1000||µg||baker's yeast, fortified food and beverage products, poultry liver|
|Cobalamin (B12)||2.0||2.4||ND||µg||shellfish, beef, animal liver, fortified food and beverage products|
|Vitamin C||75||90||2000||mg||fortified beverages, dried sweet peppers, raw acerola, dried chives and coriander, rose hips, fortified food products|
|Vitamin D||10||15||100||µg||cod liver oil, mushrooms (if exposed to ultraviolet light), halibut, mackerel, canned sockeye salmon|
|?-tocopherol (Vitamin E)||12||15||1000||mg||wheat germ oil, fortified food and beverage products, hazelnut oil, fortified peanut butter, chili powder|
|Vitamin K||NE||120||ND||µg||dried spices, fresh parsley, cooked and raw kale, chard, other leaf vegetables|
|Choline||NE||550||3500||mg||egg yolk, organ meats from beef and pork, soybean oil, fish roe|
|Calcium||800||1000||2500||mg||fortified cereals, beverages, tofu, energy bars, and baby foods, dried basil and other spices, dried whey, cheese, milk powder|
|Chromium||NE||35||ND||µg||broccoli, turkey ham, dried apricots, tuna, pineapple, grape juice|
|Copper||700||900||10000||µg||animal liver, seaweed products, dried shiitake mushrooms, oysters, sesame seeds, cocoa powder, cashews, sunflower seeds|
|Fluoride||NE||4||10||mg||public drinking water, where fluoridation is performed or natural fluorides are present, tea, raisins|
|Iodine||95||150||1100||µg||iodized salt, kelp, cod|
|Iron||6||18||45||mg||dried thyme and other spices, fortified foods, including baby foods, animal organ meats|
|Magnesium||350||420||350||mg||crude rice bran, cottonseed flour, hemp seeds, dried spices, cocoa powder, fortified beverages|
|Manganese||NE||2.3||11||mg||fortified beverages and infant formulas, ground cloves and other dried spices, chickpeas, fortified breakfast cereals|
|Molybdenum||34||45||2000||µg||legumes, grain products, nuts and seeds|
|Phosphorus||580||700||4000||mg||baking powder, instant pudding, cottonseed meal, hemp seeds, fortified beverages, dried whey|
|Potassium||NE||4700||ND||mg||baking powder, dried parsley and other spices, instant tea and instant coffee, dried tomatoes, dried sweet peppers, soy sauce|
|Selenium||45||55||400||µg||Brazil nuts and mixed nuts, animal kidneys, dried eggs, oysters, dried cod|
|Sodium||NE||1500||2300||mg||table salt, baking soda, soup bouillon cube, seasoning mixes, onion soup mix, fish sauce|
|Zinc||9.4||11||40||mg||oysters, fortified breakfast cereals, baby foods, beverages, peanut butter, and energy bars, wheat germ|
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.
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:
RDA/AI is shown below for males and females aged 19-70 years.
|Substance||Amount (males)||Amount (females)||Top Sources in Common Measures|
|Water[i]||3.7 L/day||2.7 L/day||water, watermelon, iceberg lettuce|
|Carbohydrates||45-65% of calories[ii]||milk, grains, fruits, vegetables|
|130 g/day||130 g/day|
|Protein[iii]||10-35% of calories[iv]||meats, fish, legumes (pulses and lentils), nuts, milk, cheeses, eggs|
|56 g/day||46 g/day|
|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 and oil, safflower oil|
|alpha-Linolenic acid, an omega-3 fatty acid (polyunsaturated)||1.6 g/day||1.1 g/day||Linseed oil (flax seed), chia seed, hemp seed, walnut, soybeans|
|Cholesterol||300 milligrams(mg)||chicken giblets, turkey giblets, beef liver, egg yolk|
|Trans fatty acids||As low as possible||partially hydrogenated oils, margarine|
|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||non-natural sweet foods: sweets, cookies, cakes, jams, energy and soda drinks, many processed foods|
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."
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. The only DRIs to have been revised since that meeting are vitamin D and calcium.
|% calories from total fat <= 35%||59.4%|
|% calories from saturated fat < 10%||55.8%|
|Cholesterol intake < 300 mg||10.4%|
|Sodium intake <= 2,300 mg||29.8%|
..., 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".