Intakes folates, recommended

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. 

Milk is an excellent source of calcium, phosphorus, riboflavin (vitamin B2), thiamine (vitamin Bl) and vitamin B12, and a valuable source of folate, niacin, magnesium and zinc (Food Standards Agency, 2002). In particular, dairy products are an important source of calcium, which is vital for maintaining optimal bone health in humans (Prentice, 2004). The vitamins and minerals it provides are all bioavailable (i.e. available for absorption and use by the body) and thus milk consumption in humans increases the chances of achieving nutritional recommendations for daily vitamins and mineral intake (Bellew et al., 2000). 

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)... 

Folate play an important role in the biosynthesis of DNA bases and in amino acid metabolism. An adeguate intake of folate reduces the risk of abnormalities in early embryonic brain development, specifically the risk of malformations of the embryonic brain/spinal cord. Therefore a proper intake is strictly recommended for pregnant women. Megaloblastic anemia is the ultimate consequence of an inadequate folate intake. No adverse effects have been associated with the consumption of excess folate from foods [417]. 

LB Bailey. Folate intake recommendations from a nutritional science perspective. Cereal Foods World 40 63-66, 1995. 

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

Folate antagonists (eg, methotrexate and certain antiepileptics) are used in treatment for various diseases, but their adrninistration can lead to a functional folate deficiency. Folate utilisation can be impaired by a depletion of zinc (see ZiNC COMPOUNDS). In humans, the intestinal bmsh border folate conjugase is a zinc metaUoenzyme (72). One study iadicates that the substantial consumption of alcohol, when combiaed with an iaadequate iatake of folate and methionine, may increase the risk of colon cancer (73). Based on this study, it is recommended to avoid excess alcohol consumption and increase folate intake to lower the risk of colon cancer. 

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). 

Molioy, A. M., Daly S Mills, ]. L., Kirke, J Whitehead, A., Ramsbottom, D., Conley, M., W eir, D. C-, and Scott,). M. (1997). Thermolabile variant of 5,10-methyleneletrahydro-folate reductase associated with low reti-oell folates Implications for folate intake recommendations. Littcft 349, 1591-1593. 

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... 

A. Molloy, et al. Thermolabile variant of 5.10-methylenetetrahydrofolate reductase associated with low red-cell folate implications for folate intake recommendations. Lancet 349,1591 (1997). 

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. " ... 

Bailey, L. B., Folate, methyl-related nutrients, alcohol, and the MTHFR 677C—>T polymorphism affect cancer risk Intake recommendations, J. Nutr. 133, 3748S— 37538, 2003. 

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 view of evidence linking folate intake with neural tube defects in the fetus, it is recommended that all women capable of becoming pregnant consume 4(X) pg from supplements... 

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... 

Generally, consumers intake of folates from natural sources is considered to be below the recommendations to meet physiological requirements. In consequence, folate deficiency is known to increase the risk of neural tube... 

Mild hyperhomocysteinemia due to inadequate intake of folate and vitamin Bi2 is associated with an increased risk of cardiovascular disease [7]. The number of persons at risk vastly exceeds the number of patients with inborn errors of metabolism, and public health policy recommendations for screening and intervention in patients with mild hyperhomocysteinemia await ongoing clinical trials. 

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. 

The high concentration of circulating folate in newborn infants coincides with the rapid rate of cell division in the first few months of life and is reflected in the higher folate requirement for infants on a weight basis than for adults. Though the recommendation standards (see Table 2) may underestimate the quantities consumed by many breastfed infants, intake is generally sufficiently above the recommendations that folate deficiency is unlikely. 

Folate Folate, a B-complex vitamin, includes the naturally occurring form found in foods as well as the synthetic form (folic acid) found in fortified foods and supplements. The rationale for the recommendation that all women who may become pregnant should take a daily 400 pg folic acid supplement, a preventive measure to reduce the risk of NTDs, has already been discussed. Folate intake is important throughout pregnancy because... 

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