Tolerable upper intake level UL

Tolerable Upper Intake Level (UL) UL is the highest average daily nutrient intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects may increase. The UL is not intended to be a recommended level of intake. ULs are useful because of the increased availability of fortified foods and the increased use of dietary supplements. The UL applies to chronic daily use. For some nutrients, there may be insufficient data on which to develop a UL. 

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... 

A Tolerable Upper Intake Level (UL). The UL is the maximum intake by an individual that is unlikely to pose risks of adverse health effects in almost all (97-98%)individu-als. It includes intake of a nutrient from all sources (food, fortified food, water, and sup-dements). Water can include fluoride and minerals depending on the source of water. "Tolerable" is used to "avoid implying any possible beneficial effect." It is the amount of vitamin that can be "tolerated" without the person s exhibiting or experiencing adverse reactions. The UL should not be considered the upper dose for those who self-dose with megadoses of vitamins. 

The Recommended Dietary Allowance (RDA) for Mo in adult women and men is 45 pg per day, while the Tolerable Upper Intake Level (UL) in the USA is 2000 pg per day, this level being based on impaired reproductive function and growth in am-mals (Anonymous 2001). 

The Tolerable Upper Intake Level (UL) refers to the highest level of daily nutrient intake consumed over time that is likely to pose no risks of adverse effects for almost all healthy individuals in the general population. Adverse effects are defined as any significant alteration in the structure or function of the human organism. The... 

It has been suggested that treatment with supraphysiologic levels of iodine has potential therapeutic uses beyond thyronine function (Miller, 2006). Some clinicians believe that all tissues in the human body should be saturated with iodine (Flechas, 2005). Maintenance of the equilibrium between thyroidal and extrathyroidal iodine is estimated to require about six times the tolerable upper intake level (UL) (Berson and Yalow, 1954). Controlled chronic safety data for daily iodine intake at these levels are difficult to find even though physicians prescribed daily iodine therapy at doses that ranged from 10 to 100 times the UL during the first half of the twentieth century (Kelly, 1961). 

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). 

A Tolerable Upper Intake Level (UL) is the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects to almost all individutils in the general population. Unless otherwise specified, the UL represents total intake from food, water, and supplements. Due to alack of suitable data, ULs could not be established for vitamin K, thiamin, riboflavin, vitamin B, pantothenic acid, biotin, and carotenoids. In the absence of a UL, extra caution may be warranted in consuming levels above recommended intakes. Members of the general population should be advised not to routinely exceed the UL. The UL is not meant to apply to individuals who are treated with the nutrient under medical supervision or to individuals with predisposing conditions that modify their sensitivity to the nutrient As preformed vitamin A only... 

The amount of vitamin E required by the body depends upon its size and the amount of polyunsaturated fats in the diet, as vitamin E is needed to protect these fats from oxidation. The requirement for vitamin E depends upon intake of refined oils, fried foods, or rancid oils. Supplemental estrogen or estrogen imbalance in women increases the need for vitamin E, as does air pollution. The recommended dietary allowance (RDA) for vitamin E is really quite low, many people do not consume this in their diet alone. Table 19.1 lists the RDAs and tolerable upper intake levels (ULs) for vitamin E. The new recommendations for vitamin E are expressed as milligrams of RRR-a-tocopherol equivalents. Dietary supplements of vitamin E are labeled in terms of international units (lU). 1 mg of synthetic vitamin E (a//-rac-a-tocopheryl acetate is equivalent to 1 lU vitamin E, but only 0.45 mg RRR-a-tocopherol. 1 mg of natural vitamin E (RRR-a-tocopherol) provides 1.5 lU. For the LIE, the Food and Nutrition Board recommended 1000 mg of any a-tocopherol form, which is equivalent to 1500 lU RRR- or 100 lEI all-rac-a-tocopherol (Food and Nutrition Board, 2000 Hathcock et al., 2005 Combs, 2008). 

A risk assessment model is irsed to determine tolerable upper intake levels (ULs) of consumed nutrients. Sufficient data do not exist at this time to allow use of the risk assessment model for determining ULs for any of the A As. Furthermore, athletes are highly unlikely to indulge in chronic excessive use of individual AAs, inasmuch as the AAs have no perceived value to them at dangerous levels, plus the fact that there is potential for stomach distress and discomfort involved in that practice. Consequently, collecting data on AA toxidty is difficult and possibly unnecessary. Some valuable information on this topic was recently reviewed by Garlick in a brief summary of available evidence on the safety of individual AAs when taken in excess. Also see Section 15.6 for some potential adverse evraits of individual AAs. 

The Food and Nutrition Board of the U.S. National Academy of Sciences has recently devised a new nomenclature for human nutrient needs [30]. Dietary Reference Intakes (DRI) refer to a set of four nutrient-based reference values, termed the estimated average requirement (EAR), the recommended dietary allowance (RDA), adequate intake (AI), and the tolerable upper intake level (UL). The EAR is defined in the same way as in the CEC and UK recommendations. The RDA is now somewhat more rigorously defined to be the EAR + 2 SD (standard deviations), i.e. equivalent to the RNI and PRI in the UK and CEC systems. 

Evidence of widespread manganese deficiency in human populations is lacking. Typically, manganese intakes approximate the 2001 US Institute of Medicine s suggested adequate intakes as follows 3 [tg/day for infants 0-6 months old, 0.6 mg/day for infants 7-12 months old, 1.2-1.9 mg/day for children 1-13 years old, 1.6-2.2 mg/day for older children, and 1.8-2.6 mg/day for adults. The Tolerable Upper Intake Level (UL) is the highest level of a daily nutrient intake that is likely to pose no risk of adverse health effects in almost all individuals. The Institute of Medicine s recommended intakes for manganese set ULs at 2, 3, and 6 mg/day for children 1-3, 4—8, and 9-13 years old, respectively. Values were set at 9 mg/day for adolescents 14—18 years old and at 11 mg/day for adults. 

Recommended dietary allowances (RDA) for the US and Canada were recently revised by the Institute of Medicine (lOM). Owing to the serious, potentially irreversible, effects caused by an excess of vitamin A, guidelines were also established for a tolerable upper intake level (UL), defined as the highest intake of a nutrient that is likely to pose no risk of adverse health effects in nearly all healthy individuals. The 2001 RDA and UL for vitamin A for various life stages are listed in Table 2. 

Table 2 Recommended dietary allowances (RDA) for vitamin A in micrograms ( g), retinol activity equivalents (RAE) and international units (lU), and tolerable upper intake levels (UL, pg retinol day" ) for children and adults ...

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