Daily allowance

Of the water-soluble vitamins, intakes of nicotinic acid [59-67-6] on the order of 10 to 30 times the recommended daily allowance (RE)A) have been shown to cause flushing, headache, nausea, and moderate lowering of semm cholesterol with concurrent increases in semm glucose. Toxic levels of foHc acid [59-30-3] are ca 20 mg/d in infants, and probably approach 400 mg/d in adults. The body seems able to tolerate very large intakes of ascorbic acid [50-81-7] (vitamin C) without iH effect, but levels in excess of 9 g/d have been reported to cause increases in urinary oxaHc acid excretion. Urinary and blood uric acid also rise as a result of high intakes of ascorbic acid, and these factors may increase the tendency for formation of kidney or bladder stones. AH other water-soluble vitamins possess an even wider margin of safety and present no practical problem (82). 

Toxicity. The acceptable daily allowance, which may be ingested without any risk of harm, is 1050 mg for a 70-kg healthy person (20). There is also no evidence in the Hterature that ingestion of up to 10 g vitamin C per day constitutes a serious health risk for humans. 

The amount of foHc acid required for daily iatake is estimated based oa the minimum amouat required to maintain a certaia level of semm folate. The recommeaded dietary allowance (RDA) for foHc acid accounts for daily losses and makes allowances for variation ia iadividual aeeds and bioavailabiUty from food sources (85). The U.S. recommended daily allowance for adults is 400 p.g and for pregnant women is 800 ]1 (Table 4). 

Thiamine requirements vary and, with a lack of significant storage capabiHty, a constant intake is needed or deficiency can occur relatively quickly. Human recommended daily allowances (RDAs) in the United States ate based on calorie intake at the level of 0.50 mg/4184 kj (1000 kcal) for healthy individuals (Table 2). As Httle as 0.15—0.20 mg/4184 kJ will prevent deficiency signs but 0.35—0.40 mg/4184 kJ are requited to maintain near normal urinary excretion levels and associated enzyme activities. Pregnant and lactating women requite higher levels of supplementation. Other countries have set different recommended levels (1,37,38). 

The recommended daily allowance for vitamin E ranges from 10 international units (1 lU = 1 mg all-rac-prevent vitamin E deficiency in humans. High levels enhance immune responses in both animals and humans. Requirements for animals vary from 3 USP units /kg diet for hamsters to 70 lU /kg diet for cats (13). The complete metaboHsm of vitamin E in animals or humans is not known. The primary excreted breakdown products of a-tocopherol in the body are gluconurides of tocopheronic acid (27) (Eig. 6). These are derived from the primary metaboUte a-tocopheryl quinone (9) (see Eig. 2) (44,45). 

The recommended daily allowances of calcium are children to 10 years of age, 360—800 mg teenage children, 1200 mg adults, 800 mg, increasing to 1200 mg during pregnancy and lactation (29). Cow s milk suppHes ca 1.27 g/L of calcium in available form. 

C03-0076. The U.S. Recommended Daily Allowances (RDAs) of several vitamins follow. In each case,... 

Recent scientific studies have clearly established the nutritional role of dietary fiber in several health conditions (Jalili et al., 2000), such as hypercholesterolemia (Topping et al., 1990), diabetes (Chandalia et al., 2000) and bowel function. It is also effective in preventing urinary stones (Ohkawa et al., 1984). The Food and Nutrition Board (Institute of Medicine Report, 2001) recommended a daily allowance for fiber of 25-30 g, though it is not an essential nutrient. Rice bran fiber offers a good source of non-bloating dietary fiber and is marketed as RiceMucil by NutraStar Company in the USA. 

Most CF patients have an increased caloric need due to increased energy expenditure through increased work of breathing and increased basal metabolism. Prevention of malnutrition requires early nutritional intervention. In patients with mild lung disease and well-controlled absorption, required caloric intake is approximately 100% to 120% of the recommended daily allowance (RDA) for age.15 As lung disease progresses, caloric requirements increase. 

Coenzyme Q10 is an antioxidant essential for mitochondrial function. A dose of 1200 mg daily was associated with a slower decline in UPDRS scores than patients not receiving coenzyme Q10. Lower doses were no better than placebo, but the drug continues to be studied in doses up to 2400 mg daily. Many formulations contain vitamin E, and patients should not exceed recommended daily allowances of this vitamin, as bleeding times may be prolonged.42,43... 

In the United States, the recommended daily allowances (RDAs) are periodically developed by the... 

Daily allowable limit, pg Carcinogenic PAHs (except diet) 0.048 2... 

Recommended Daily Allowances," Food and Nutrition Board, National Academy of Sciences, National Research Council,... 

Human adult needs for this vitamin (vitamins) are not established quantitatively. Most human studies have involved preventing or curing rickets in infants or children, and the recommended daily allowance of the Food and Nutrition Board is 400 units. Even among "normal" children, however, there is evidence of variation in vitamin D needs. According to Spies and Butt,38 "The activated milk does not exhibit sufficient potency in vitamin D for the prevention of rickets in cases in which a susceptibility exists" (italics added). They note that "susceptible" children may require 5,000 to 10,000 units daily. 

The figure comes from a series of reports issued by the Institute of Medicine over the past decade. The experts who authored these reports revisited the question of recommended daily allowances and other measures of nutrient adequacy, and made recommendations regarding macronutrients (proteins, carbohydrates, fats and oils) and for micronutrients (vitamins and minerals). The Institute has had a long history of developing recommended intake levels, but in the recent... 

The US daily allowances-The US daily allowances for vitamin K have not been officially established, but have been estimated to be 10 to 20 meg for infants, 15 to 100 meg for children and adolescents, and 70 to 140 meg for adults. Usually, dietary vitamin K will satisfy these requirements, except during the first 5 to 8 days of the neonatal period. 

Metal Function Source Toxicity (when in excess) Recommended daily allowance... 

According to the directive 90/496/EEC on nutrition labeling of foodstuffs [401], the vitamin levels in food have to be reported as relative daily allowance (RDA%). This information is mandatory on the label if any claim about their content [402] or addition of vitamins [403] is made. The European Union Regulation 1925/2006 stipulates the vitamin formulations that may be added to foods [403]. 

Vitamin Active compound Sources Recommended daily allowances... 

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