Requirements, estimated average

Reference Intakes (DRIs). In the past, the recommended dietary allowances (RDAs), which are the levels of intake of essential nutrients that are considered to be adequate to meet the known nutritional needs of practically all healthy persons, were the primary reference value for vitamins and other nutrients. The DRIs also include other reference values, such as the estimated average requirement (EAR) and the adequate intake (AI). The RDA, EAR, and AI reference standards define nutritional intake adequacy. Since these recommendations are given for healthy populations in general and not for individuals, special problems, such as premature birth, inherited metabolic disorders, infections, chronic disease, and use of medications, are not covered by the requirements. Separate RDAs have been developed for pregnant and lactating women. Vitamin supplementation may be required by patients with special conditions and for those who do not consume an appropriate diet. 

Dietary Reference Intakes for vitamins and minerals in individuals one year and older. EAR = Estimated Average Requirement RDA = Recommended Dietary Allowance ... 

Figures for infants under 12 months are Adequate Intakes, based on the observed mean intake of infants fed principally on breast milk for nutrients other than vitamin K, figures are RDA, based on estimated average requirement +2 SD figures for vitamin K are Adequate Intakes, based on observed ...

Adequate Intake For some vitamins, notably biotin (Section 11.5) and pantothenic acid (Section 12.6), dietary deficiency is more-or-less unknown, and there are no data from which to estimate average requirements or derive reference intakes. In such cases, the observed range of intakes is obviously more than adequate to meet requirements, and the average intake is used to calculate an adequate intake figure. 

Based on the plasma concentration of a-tocopherol to prevent significant hemolysis in vitro (14 to 16 /xmol per L), the U.S./Canadian estimated average requirement is 12 mg per day, giving a Recommended Dietary Amount (RDA) of 15 mg per day (Institute of Medicine, 2000) - a 50% increase on the previous RDA (National Research Council, 1989). This increase arose partly as a result of considering only the 2R isomers in dietary intake (Section 4.1). Average intakes are of the order of 8 to 12 mg of a -tocopherol equivalent per day it would be difficult meet this reference intake without significant changes in diet or use of supplements. 

Hansen CM, Shultz TD, Kwak HK, Memon HS, and Leklem JE (2001) Assessment of vitamin B-6 status in young women consuming a controlled diet containing four levels ofvitamin B-6 provides an estimated average requirement and recommended dietary allowance./owma/ of Nutrition 131,1777-86. 

Optimal dietary intake is difficult to determine. Dietary Reference Intakes (DRIs) in the US are reference values that are quantitative estimates of nutrient intakes to be used for planning and assessing diets for apparently healthy people. DRIs are composed of reference values including Estimated Average Requirements (EARs), Recoimnended Dietary Allowances (RDAs), Adequate Intakes (AIs) and Tolerable Upper Intake Levels (ULs). Most nations have established the eqnivalent ofthe US DRIs. These are consensus and statistical valnes obtained from retrospective public health dietary studies, controlled experiments on metabolic wards, epidemiological surveys, isotopic tracer investigations, and extrapolation from animal models. 

The optimal dietary requirements of vitamin E for humans are not yet known, especially with the emergence of new paradigms regarding adequate levels of dietary micronutrients (Chalem, 1999). Recommendations in the United States and Canada have been reevaluated, and a new concept of Dietary Reference Intake (DRI, 2000) was issued for vitamin E and other antioxidants. The DRI recommendation should prevent specific deficiency disorders, support health in general ways and minimize the risk of toxicity, which carries more tasks than the previous recommendations (DRI, 2000). Accordingly, the recommendations for intakes were set to higher levels than previously. Estimated Average Requirements (EAR) for adults, both men and women, were set to 12 mg a-tocopherol/day, RDA to 15 mg/day and Tolerable Upper Intake Level (UL) to 1000 mg/day. Moreover, the EAR and RDA are based only on the 2R-stereoisomeric forms of a-tocopherol, because the other vitamers... 

Because there has not been sufficient evidence to set an estimated average requirement (EAR), an AI based on estimated intakes has been set at 35 fig Cr per day for men and 25 fig Cr per day for women. No tolerable upper limit was set for dietary Cr " intake. ... 

Dietary Reference Intakes. There are too few studies to provide sufficient information to estimate Estimated Average Requirements (EAR) or Recommended Dietary Allowances (RDA). 

If sufficient scientific evidence is not available to calculate an Estimated Average Requirement, a reference intake called an Adequate Intake (Al) is used instead of a Recommended Dietary Allowance. The Al is a value based on experimentally derived intake levels or approximations of observed mean nutrient intakes by a group (or groups) of healthy people. The Al for children and adults is expected to meet or exceed the amount needed to maintain a defined nutritional state or criterion of adequacy in essentially all members of a specific healthy population LA = linoleic acid LNA = n-linolenic acid DHA = docosahexaenoic acid EPA = eicosapentaenoic acid TRANS-EA = trans fatty acids SAT = saturated fatty acids MONOs = monounsaturated fatty acids. 

Dietary Reference Intakes (DRIs) are used quite a lot and refer to a set of four nutrient-based reference values that represent the approach to provide quantitative estimates of nutrient intakes. The DRIs replace and expand on the Recommended Dietary Allowances (RDAs) for the United States and the Recommended Nutrient Intakes (RNIs) for Canada. The DRIs consist of the RDAs, the Tolerable Upper Intake Level (UL), the Estimated Average Requirement (EAR), and the Adequate Intake (AI). Generally, each of these values represents average daily nutrient intake of individuals in the diet (Goldhaber, 2003 Murphy and Poos, 2002 Parr et ah, 2006 Trumbo et ah, 2001 Yates et ah, 1998). In addition, dietary intake data for minerals could be assessed within the context of the bioavailability and other factors affecting the utilization of elements by the human body, such as age, sex, and health aspects (Dokkum, 1995). 

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