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).[1] 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products in the U.S. and Canada, which uses Reference Daily Intakes (RDIs) and Daily Values (%DV) which were based on outdated RDAs from 1968 but were updated as of 2016.[2]

Parameters

DRI provides several different types of reference values:[1]

  • 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, adult zinc UL is 40 mg in U.S. and 25 mg in EFSA.[3]
  • 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.

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.[4][3]

DRIs are used by both the United States and Canada, and are intended for the general public and health professionals. Applications include:

  • Composition of diets for schools, prisons, hospitals or nursing homes
  • Industries developing new foods and dietary supplements
  • Healthcare policy makers and public health officials

History

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".[5]

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.[6] None of the other DRIs have been revised since first published 1998 to 2001.

Current recommendations for United States and Canada

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.[7]

Nutrient EAR Highest RDA/AI UL[7] Unit Top common sources, 100 grams, U.S. Department of Agriculture (USDA)[8]
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[9]
Folate (B9) 320 400 1000 µg baker's yeast, fortified food and beverage products, poultry liver
Cyanocobalamin (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
α-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
Chloride NE 2300 3600 mg table salt
Chromium NE 35 ND µg broccoli, turkey ham, dried apricots, tuna, pineapple, grape juice[10]
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[11]
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:

Substance RDA/AI UL units per day
Arsenic ND
Silicon ND
Vanadium 1.8 mg

Macronutrients

RDA/AI is shown below for males and females aged 19-70 years.[7]

Substance Amount (males) Amount (females) Top Sources in Common Measures[8]
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)[12] 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 non-natural sweet foods: sweets, cookies, cakes, jams, energy and soda drinks, many processed foods
  1. ^ Includes water from food, beverages, and drinking water.
  2. ^ Acceptable Macronutrient Distribution Range (AMDR).
  3. ^ Based on 0.8 g/kg of body weight.
  4. ^ Acceptable Macronutrient Distribution Range (AMDR).

Calculating the RDA

The equations used to calculate the RDA are as follows:

"If the standard deviation (SD) of the EAR is available and the requirement for the nutrient is symmetrically distributed, the RDA is set at two SDs above the EAR:

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."[13]

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.”[14] 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.[6]

Adherence

Protein 88.9%
Vitamin A 46.0%
Vitamin C 51.0%
Vitamin E 13.6%
Thiamin 81.6%
Riboflavin 89.1%
Niacin 87.2%
Vitamin B6 73.9%
Folate 59.6%
Vitamin B12 79.7%
Phosphorus 87.2%
Magnesium 43.0%
Iron 89.5%
Selenium 91.5%
Zinc 70.8%
Copper 84.2%
Calcium 30.9%
Fiber 8.0%
Potassium 7.6%
% 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 29.8%

See also

References

  1. ^ a b "A Consumer's Guide to the DRIs (Dietary Reference Intakes)". Health Canada. 2010-11-29. Retrieved 2017-08-29.
  2. ^ "Federal Register, Food Labeling: Revision of the Nutrition and Supplement Facts Labels. FR page 33982" (PDF). US Food and Drug Administration. 27 May 2016.
  3. ^ a b Tolerable Upper Intake Levels For Vitamins And Minerals (PDF), European Food Safety Authority, 2006
  4. ^ "Overview on Dietary Reference Values for the EU population as derived by the EFSA Panel on Dietetic Products, Nutrition and Allergies" (PDF). 2017.
  5. ^ 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.
  6. ^ a b Dietary Reference Intakes for Calcium and Vitamin D. Washington DC: National Academy Press. 2011. ISBN 0-309-16394-3. Lay summaryInstitute 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".
  7. ^ a b c Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Food and Nutrition Board, Institute of Medicine, National Academies, 2004, retrieved 2009-06-09
  8. ^ a b "Search ordered by selected nutrient per 100 gram amounts: sort by nutrient among all foods, USDA National Nutrient Database for Standard Reference, SR28". 2016. Retrieved 28 October 2017.
  9. ^ "Biotin, Fact Sheet for Health Professionals". Office of Dietary Supplements, US National Institutes of Health. 3 October 2017. Retrieved 28 October 2017.
  10. ^ "Chromium". Micronutrient Information Center, Linus Pauling Institute, Oregon State University.
  11. ^ "Molybdenum". Micronutrient Information Center, Linus Pauling Institute, Oregon State University.
  12. ^ "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.
  13. ^ Panel on Micronutrients 2001
  14. ^ The Development of DRIs 1994–2004: Lessons Learned and New Challenges. Workshop Summary, November 30, 2007

External links

Acceptable daily intake

Acceptable daily intake or ADI is a measure of the amount of a specific substance (originally applied for a food additive, later also for a residue of a veterinary drug or pesticide) in food or drinking water that can be ingested (orally) on a daily basis over a lifetime without an appreciable health risk. ADIs are expressed usually in milligrams (of the substance) per kilograms of body weight per day.

Biotin

Biotin is a water-soluble B vitamin, also called vitamin B7 and formerly known as vitamin H or coenzyme R. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids.

Biotin deficiency can be caused by inadequate dietary intake or inheritance of one or more inborn genetic disorders that affect biotin metabolism. Subclinical deficiency can cause mild symptoms, such as hair thinning or skin rash typically on the face. Neonatal screening for biotinidase deficiency began in the United States in 1984, with many countries testing for this disorder at birth. Individuals born prior to 1984 are unlikely to have been screened, obscuring the true prevalence of the disorder.

Cholecalciferol

Cholecalciferol, also known as vitamin D3 and colecalciferol, is a type of vitamin D which is made by the skin when exposed to sunlight; it is also found in some foods and can be taken as a dietary supplement. It is used to treat and prevent vitamin D deficiency and associated diseases, including rickets. It is also used for familial hypophosphatemia, hypoparathyroidism that is causing low blood calcium, and Fanconi syndrome. It is usually taken by mouth.Excessive doses can result in vomiting, constipation, weakness, and confusion. Other risks include kidney stones. Normal doses are safe in pregnancy. It may not be effective in people with severe kidney disease.Cholecalciferol is made in the skin following UVB light exposure. It is converted in the liver to calcifediol (25-hydroxyvitamin D) which is then converted in the kidney to calcitriol (1,25-dihydroxyvitamin D). One of its actions is to increase the uptake of calcium by the intestines. It is found in food such as some fish, cheese, and eggs. Certain foods such as milk have cholecalciferol added to them in some countries.Cholecalciferol was first described in 1936. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Cholecalciferol is available as a generic medication and over the counter.

Cod liver oil

Cod liver oil is a dietary supplement derived from liver of cod fish (Gadidae). As with most fish oils, it contains the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Cod liver oil also contains vitamin A and vitamin D. Historically, it was given to children because vitamin D had been shown to prevent rickets, a consequence of vitamin D deficiency.

Guava

Guava () is a common tropical fruit cultivated in many tropical and subtropical regions. Psidium guajava (common guava, lemon guava) is a small tree in the myrtle family (Myrtaceae), native to Mexico, Central America, and northern South America. Although related species may also be called guavas, they belong to other species or genera, such as the "pineapple guava" Acca sellowiana. In 2011, India was the largest producer of guavas.

Hypervitaminosis

Hypervitaminosis is a condition of abnormally high storage levels of vitamins, which can lead to toxic symptoms. Specific medical names of the different conditions are derived from the vitamin involved: an excess of vitamin A, for example, is called hypervitaminosis A. Hypervitaminoses are primarily caused by fat-soluble vitamins (D and A), as these are stored by the body for longer period than the water-soluble vitamins.Generally, toxic levels of vitamins stem from high supplement intake and not from natural food. Toxicities of fat-soluble vitamins can also be caused by a large intake of highly fortified foods, but natural food rarely deliver dangerous levels of fat-soluble vitamins. The Dietary Reference Intake recommendations from the United States Department of Agriculture define a "tolerable upper intake level" for most vitamins.

Vitamin overdose can be precluded from by avoiding to take more than the normal or recommended amount of multi-vitamin supplement shown on the bottle. And do not ingest multiple vitamin-containing supplements concurrently.

Instant mashed potatoes

Instant mashed potatoes are potatoes that have been through an industrial process of cooking, mashing and dehydrating to yield a packaged convenience food that can be reconstituted by adding hot water or milk, producing an

approximation of mashed potatoes. They are available in different flavors.

Mashed potatoes can be reconstituted from potato flour, but the process is made more difficult by lumping; a key characteristic of instant mashed potatoes is that it is in the form of flakes or granules, eliminating the chunkiness. Analogous to instant mashed potatoes are instant poi made from taro and instant fufu made from yams or yam substitutes including cereals. Poha, an instant rice mush, is also much in the same spirit, as more broadly are other instant porridges, formed from flakes, granules, or pearls to avoid lumping. Brands include Smash and Idahoan Foods.

Flaked instant mashed potatoes are most commonly found in stores in the United States and Canada. Granulated forms are generally reserved more for institutional or restaurant use.

Lydia Roberts

Lydia Jane Roberts was a pioneering nutritionist in childhood nutrition, especially in creating government nutrition standards like the Recommended Dietary Allowances (RDA) of minerals and vitamins. She studied and taught at the University of Chicago, receiving her Ph.D. in home economics in 1928 and later becoming department chair in 1930.

Meal, Ready-to-Eat

The Meal, Ready-to-Eat – commonly known as the MRE – is a self-contained, individual field ration in lightweight packaging bought by the U.S. Department of Defense for its service members for use in combat or other field conditions where organized food facilities are not available. While MREs should be kept cool, they do not need to be refrigerated. MREs replaced the canned MCI, or Meal, Combat, Individual rations, in 1981, and is the intended successor to the lighter LRP ration developed by the United States Army for Special Forces and Ranger patrol units in Vietnam. MREs have also been distributed to civilians during natural disasters.

Methylsulfonylmethane

Methylsulfonylmethane (MSM) is an organosulfur compound with the formula (CH3)2SO2. It is also known by several other names including methyl sulfone and dimethyl sulfone (DMSO2). This colorless solid features the sulfonyl functional group and is considered relatively inert chemically. It occurs naturally in some primitive plants, is present in small amounts in many foods and beverages, and is marketed as a dietary supplement. It is sometimes used as a cutting agent for illicitly manufactured methamphetamine. It is also commonly found in the atmosphere above marine areas, where it is used as a carbon source by the airborne bacteria Afipia.

Morinda citrifolia

Morinda citrifolia is a fruit-bearing tree in the coffee family, Rubiaceae. Its native range extends across Southeast Asia and Australasia, and the species is now cultivated throughout the tropics and widely naturalized. Among some 100 names for the fruit across different regions are the more common English names of great morinda, Indian mulberry, noni, beach mulberry, and cheese fruit.The strong-smelling fruit has been eaten as a famine food or staple food among some cultures, and has been used in traditional medicine. In the consumer market, it has been introduced as a supplement in various formats, such as capsules, skin products, and juices.

Nutrient

A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures, such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products (ethanol or vinegar), leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host.

Different types of organism have different essential nutrients. Ascorbic acid (vitamin C) is essential, meaning it must be consumed in sufficient amounts, to humans and some other animal species, but not to all animals and not to plants, which are able to synthesize it. Nutrients may be organic or inorganic: organic compounds include most compounds containing carbon, while all other chemicals are inorganic. Inorganic nutrients include nutrients such as iron, selenium, and zinc, while organic nutrients include, among many others, energy-providing compounds and vitamins.

A classification used primarily to describe nutrient needs of animals divides nutrients into macronutrients and micronutrients. Consumed in relatively large amounts (grams or ounces), macronutrients (carbohydrates, fats, proteins, water) are used primarily to generate energy or to incorporate into tissues for growth and repair. Micronutrients are needed in smaller amounts (milligrams or micrograms); they have subtle biochemical and physiological roles in cellular processes, like vascular functions or nerve conduction. Inadequate amounts of essential nutrients, or diseases that interfere with absorption, result in a deficiency state that compromises growth, survival and reproduction. Consumer advisories for dietary nutrient intakes, such as the United States Dietary Reference Intake, are based on deficiency outcomes and provide macronutrient and micronutrient guides for both lower and upper limits of intake. In many countries, macronutrients and micronutrients in significant content are required by regulations to be displayed on food product labels. Nutrients in larger quantities than the body needs may have harmful effects. Edible plants also contain thousands of compounds generally called phytochemicals which have unknown effects on disease or health, including a diverse class with non-nutrient status called polyphenols, which remain poorly understood as of 2017.

Plant nutrients consist of more than a dozen minerals absorbed through roots, plus carbon dioxide and oxygen absorbed or released through leaves. All organisms obtain all their nutrients from the surrounding environment.

Protein (nutrient)

Proteins are essential nutrients for the human body. They are one of the building blocks of body tissue and can also serve as a fuel source. As a fuel, proteins provide as much energy density as carbohydrates: 4 kcal (17 kJ) per gram; in contrast, lipids provide 9 kcal (37 kJ) per gram. The most important aspect and defining characteristic of protein from a nutritional standpoint is its amino acid composition.Proteins are polymer chains made of amino acids linked together by peptide bonds. During human digestion, proteins are broken down in the stomach to smaller polypeptide chains via hydrochloric acid and protease actions. This is crucial for the absorption of the essential amino acids that cannot be biosynthesized by the body.There are nine essential amino acids which humans must obtain from their diet in order to prevent protein-energy malnutrition and resulting death. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. There has been debate as to whether there are 8 or 9 essential amino acids. The consensus seems to lean towards 9 since histidine is not synthesized in adults. There are five amino acids which humans are able to synthesize in the body. These five are alanine, aspartic acid, asparagine, glutamic acid and serine. There are six conditionally essential amino acids whose synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress. These six are arginine, cysteine, glycine, glutamine, proline and tyrosine.Dietary sources of protein include both animals and plants: meats, dairy products, fish and eggs, as well as grains, legumes and nuts. Vegans can get enough essential amino acids by eating plant proteins.

Reference Daily Intake

The Reference Daily Intake (RDI) is the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97–98% of healthy individuals in every demographic in the United States. While developed for the US population, it has been adopted by other countries, though not universally.

The RDI is used to determine the Daily Value (DV) of foods, which is printed on nutrition facts labels (as % DV) in the United States and Canada, and is regulated by the Food and Drug Administration (FDA) and Health Canada. The labels "high", "rich in", or "excellent source of" may be used for a food if it contains 20% or more of the RDI. The labels "good source", "contains", or "provides" may be used on a food if it contains between 10% and 20% of the RDI.The Recommended Dietary Allowances (RDAs) were a set of nutrition recommendations that evolved into both the Dietary Reference Intake (DRI) system of nutrition recommendations (which still defines RDA values) and the RDIs used for food labelling. The first regulations governing U.S. nutrition labels specified a % U.S. RDA declaration based on the current RDA values, which had been published in 1968. Later, the % U.S. RDA was renamed the %DV and the RDA values that the %DVs were based on became the RDIs.

The RDAs (and later the RDA values within the DRI) were regularly revised to reflect the latest scientific information, but although the nutrition labeling regulations were occasionally updated, the existing RDI values were not changed, so that until 2016 many of the DVs used on nutrition facts labels were still based on the outdated RDAs from 1968. In 2016, the Food and Drug Administration published changes to the regulations including updated RDIs and DVs based primarily on the RDAs in the current DRI.

Selenium deficiency

Selenium deficiency is relatively rare in healthy well-nourished individuals. Few cases in humans have been reported.

Serum chloride

Chloride is an anion in the human body needed for metabolism (the process of turning food into energy). It also helps keep the body's acid-base balance. The amount of serum chloride is carefully controlled by the kidneys.Chloride ions have important physiological roles. For instance, in the central nervous system, the inhibitory action of glycine and some of the action of GABA relies on the entry of Cl− into specific neurons. Also, the chloride-bicarbonate exchanger biological transport protein relies on the chloride ion to increase the blood's capacity of carbon dioxide, in the form of the bicarbonate ion; this is the mechanism underpinning the chloride shift occurring as the blood passes through oxygen-consuming capillary beds.

The normal blood reference range of chloride for adults in most labs is 96 to 106 milliequivalents (mEq) per liter. The normal range may vary slightly from lab to lab. Normal ranges are usually shown next to results in the lab report. A diagnostic test may use a chloridometer to determine the serum chloride level.

The North American Dietary Reference Intake recommends a daily intake of between 2300 and 3600 mg/day for 25-year-old males.

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