Folate dietary recommendation

The amount of foHc acid required for daily intake is estimated based on the minimum amount required to maintain a certain level of semm folate. The recommended dietary allowance (RDA) for foHc acid accounts for daily losses and makes allowances for variation in individual needs and bioavailabiHty from food sources (85). The U.S. recommended daily allowance for adults is 400 )Ug and for pregnant women is 800 X (Table 4). 

The folate requirement is the minimum amount necessary to prevent deficiency. Dietary recommendations for populations, however, must allow a margin of safety to cover the needs of the vast majority of the population. As is the case with most nutrients, the margin of safety for folate requirement corresponds to two standard deviations above the mean requirement for a population and should therefore meet the needs of 97.5% of the population. Thus, international dietary recommendations contain allowances for individual variability, the bioavailability of folate from different foodstuffs, and periods of low intake and increased use. Current international folate recommendations for FAO/ WHO, USA/Canada, and the European Union are listed in Table 2. 

The lack of hard evidence about the extent of supplementation required in pregnancy prompted the development of a laboratory-based assessment of metabolic turnover, which involved the assay of total daily folate catabolites (along with intact folate) in the urine of pregnant women. The rationale of the procedure was that this catabolic product represents an ineluctable daily loss of folate, the replacement of which should constitute the daily requirement. Correcting for individual variation in catabolite excretion and the bioavailability of dietary folate, the recommended allowances based on this mode of assessment are in close agreement with the latest recommendations of the USA/Canada and FAO/WHO. The data produced by the catabolite-excretion method may provide a useful adjunct to current methods... 

Folate deficiency The recommended dietary intake of folate has been increased (also protects against neural tube defects in the fetus), and additional folate is now added to flour (bread, pasta, and other products made liom flour)... 

Except during pregnancy and lactation, do not give folic acid in therapeutic doses greater than 0.4 mg/day until pernicious anemia has been ruled out. Do not include daily doses exceeding the Recommended Dietary Allowance in multivitamin preparations if therapeutic amounts are necessary, give folic acid separately. Elderly It may be prudent to consider the status of folate in people older than 65 years of age. 

An important indication for folic acid has become the prevention of neural tube defects when given to women three months before conception and during the first trimester. The Recommended Dietary Allowance (RDA) for folate equivalents for pregnant women is 600-800 pg, twice the normal RDA of 400 pg for women who are not pregnant. 

Sulfasalazine has a high incidence of adverse effects, most of which are attributable to systemic effects of the sulfapyridine molecule. Slow acetylators of sulfapyridine have more frequent and more severe adverse effects than fast acetylators. Up to 40% of patients cannot tolerate therapeutic doses of sulfasalazine. The most common problems are dose-related and include nausea, gastrointestinal upset, headaches, arthralgias, myalgias, bone marrow suppression, and malaise. Hypersensitivity to sulfapyridine (or, rarely, 5-ASA) can result in fever, exfoliative dermatitis, pancreatitis, pneumonitis, hemolytic anemia, pericarditis, or hepatitis. Sulfasalazine has also been associated with oligospermia, which reverses upon discontinuation of the drug. Sulfasalazine impairs folate absorption and processing hence, dietary supplementation with 1 mg/d folic acid is recommended. 

Herbert V (1987a) Recommended dietary intakes (RDI) of folate in humans. American Journal of Clinical Nutrition 45, 661-70. 

Folate is a water-soluble vitamin. The recommended daily allowances (RDAs) of folate for the adult man and woman are 20fJ and 101) pg, respectively. The RDA is defined in the Preface. Folate is critically important for growth, and for this reason it is required in increased amounts during pregnancy (400 pg. The need for dietary folate remains elevated after pregnancy and during lactation because of the Irans-... 

Based on folate concentrations in liver biopsy samples, and assuming that the liver contains about half of ail body stores, total body stores of folate are estimated to be between 12 and 28 Kinetic studies that show both fast-turnover and very-slow-turnover folate pools indicate that about 0.5% to 1% of body stores are catabolized or excreted daily,suggesting a minimum daily requirement of between 60 and 280)Llg to replace losses. In calculating nutritional requirement, the concept of dietary folate equivalents (DFE) has been used to adjust for the nearly 50% lower bioavailabihty of food folate compared with supplemental folic acid, such that 1 p.g DFE = 0.6 Llg of folic acid from fortified food = 1 j,g of food folate 0.5 p.g foUc acid supplement taken on an empty stomach. Before the fortification program of cereal grains with folic acid conducted between 1988 and 1994, the median intake of folate from food in the United States was approximately 250p.g/day this figure is expected to increase by about 100 Llg/day after fortification. Recommendations... 

Bailey, L. B. (1992). Folate—Evaluation of new recommended dietary allowance. J. Am. Diet. Assoc. 92, 463. 

The mechanisms by which vitamins prevent illnesses are not weU understood, and the amounts needed to lower risks for certain disease conditions may be higher than the current recommended levels for preventing nutritional deficiencies. For example, the Institute of Medicine recommends that to prevent neural tube birth defects, women of child-bearing age should consume 400 Xg of folic acid per day (but not more than 1000 Xg/day) from fortified foods and/or dietary supplements in addition to folates obtained from a varied diet. " < Ascorbic acid intakes of 80-200mg daily (8-20 times the amounts needed to prevent scurvy) may be necessary to enhance certain physiological functions and minimize specific disease risks. " ... 

Tree nuts can be good dietary sources (>10% of recommended dietary allowances [RDA] or adequate intake [Al]) of most vitamins except vitamins A and cobalamin (B,2). At suggested consumption level (1.5 ounces or 42.5g/day), acorn and pine nuts are excellent sources of folate and vitamin K (Table 2.7). In case of thiamin (Bj), niacin (B3), and pyridoxine (Bg), tree nuts offer alternative sources of these vitamins when more abundant animal sources are not available or are not consumed. 

In addition to the macronutrients, nuts contain significant amounts of essential micronutrients such as vitamin E, calcium, magnesium, potassium, and folate [29]. Nuts are also one of the richest whole foods sources of vitamin E and were specifically recommended in the 2005 Dietary... 

Sources Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Huoride (1997) Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin 85, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998) EHetary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000) Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc (2001) Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005) and EHetary Reference Intakes for Calcium and Vitamin D (2011). These reports may be accessed via www.nap.edu 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 individuals in the general population. Unless otherwise specified, the UL represents total intake from food, water, and supplements. Due to a lack of suitable data, ULs could not be established for vitamin K, thiamin, riboflavin, vitamin B12, 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 ply to individuals who are treated with the nutrient under medical supervision or to individuals with predisposing conditions that modify their sensitivity to the nutrient... 

Recommended Dietary Allowances, 10th ed., 1989, NRC-National Academy of Sciences, p. 285. ihe RDA are expressed in terms of "total" folacin, that is, the amount of folic acid activity available from all food folates. 

National Research Council, Food and Nutrition Board, and Institute of Medicine (1998) Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B-6, folate, vitamin B-12, pantothenic add, biotin, and choline. In Recommended Dietary Allowances., pp. 374-389. Washington, DC. National Academy Press. 

Table 2 Recommended dietary folate allowances for various population groups (pgday ...

The 1998 recommendations for folate are expressed using a term called the dietary folate equivalent (DFE). The DFE was developed to help account for the difference in bioavailability between naturally occurring dietary folate and synthetic folic acid. The Food and Nutrition Board of the US National Academy of Sciences reasoned that, since folic acid in supplements or in fortified food is 85% bioavailable, but food folate is only about 50% bioavailable, folic acid taken as supplements or in fortified food is 85/50 (i.e., 1.7) times more available. Thus, the calculation of the DFE for a mixture of synthetic folic acid and food is pg of DFE = pg food folate + (1.7 x pg synthetic folate). 

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