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PubMed1989

[Neurologic and psychologic disorders in folic acid deficiency].

Folic acid deficiency is the most common of all vitamin deficiencies in North America and in Western Europe, usually in association with other vitamin deficiencies. Alcoholism is considered to be the most frequent cause of folic acid deficiency, as far as the Western world is concerned. Severe neurological and mental disturbances can develop in case of folate deficiency probably long before the manifestation of macrocythaemia. Among the neurological sequelae of folic acid deficiency the main phenomena that are discussed as likely are polyneuropathy, funicular disease of the spine and restless legs. The psychic or mental symptoms that can be ascribed to folic acid deficiency are non-specific and correspond with the symptoms of a psychosis that can have physical causes. Administration of folic acid has repeatedly resulted in significant improvements of neurological and mental symptoms in folic acid deficiency. The exact mechanisms involved in a damage to the nervous system are not sufficiently clarified for folic acid deficiency. Diagnosis is effected mainly by determining the folic acid concentration in the serum. Daily administration of approx. 1.25-15 mg folic acid (oral and/or parenteral) is recommended. Mild side effects such as tiredness and irritability have been noted only with high folic acid dosage levels.

Folic Acid Deficiency↗
PubMedDate not supplied

Reduction of the teratogenic effects of phenytoin by folic acid and a mixture of folic acid, vitamins, and amino acids: a preliminary trial.

Four groups of pregnant rats were used to study the effects of dietary supplements of folic acid (FA) alone or a mixture of FA, vitamins (Vit), and amino acids (AA) on the teratogenic effects of phenytoin (PHT). Groups A, B, and C received intraperitoneal (i.p.) injections of high-dose (75 mg/kg/day) phenytoin (PHT) between 9 and 11 days of gestation, while the controls, group D, rats received distilled water. The diet was modified in groups A and B. Group A received a mixture of FA, Vit, and AA, while group B received FA supplementation alone. Groups C and D received a regular diet. We found that PHT, when administered without dietary supplementation, resulted in a decrease in weight and length of the fetuses, an increased rate of subcutaneous (s.c.) bleeding, a retardation of ossification centers, and an increased number of malformations. Supplementation of the diet with FA alone or FA with Vit and AA resulted in statistically greater fetal weight and length, decreased subcutaneous bleeding, more ossification centers, and fewer malformations. The mixture of FA and Vit and AA was superior to FA alone in reducing the incidence of internal abnormalities, ossification abnormalities of the distant phalanxes, and s.c. bleeding.

Amino Acids↗
PubMed1977

Oscillations and cell development in Dictyostelium discoideum stimulated by folic acid pulses.

Folic acid is known to be a chemoattractant of pre-aggregation cells of Dictyostelium discoideum. When supplied in pulses, folic acid induces biochemical oscillations and stimulates the development of pre-aggregation to aggregation-competent amoebae. The continuous supply of folic acid has no stimulatory effect. Folic-acid-induced oscillations are accompanied by periodic changes in the cyclic AMP concentration. Pulses of folic acid applied with rhythms between 7 and 11 min efficiently induce oscillations. In contrast, a rhythm of 2 min neither induces oscillations nor suppresses them. Cells start to oscillate with a rhythm of about 8 min. This inherent rhythm is independent of the inducing rhythm. Oscillating cells are less sensitive to folic acid than pre-oscillating ones. They respond only to high concentrations of folic acid which also interact with the oscillating system.

Cyclic AMP↗
PubMed2001

Quantifying the effect of folic acid.

BACKGROUND: Folic acid is known to prevent neural-tube defects (NTDs) but the size of the effect for a given dose is unclear. We aimed to quantify such an effect. METHODS: We used published data from 13 studies of folic acid supplementation on serum folate concentrations and results from a large cohort study of the risk of NTDs according to serum folate, to measure the preventive effect of specified increases in intake of folic acid. FINDINGS: Serum folate concentrations increase by 0.94 ng/mL (95% CI 0.77-1.10) for every 0.1 mg/day increase in folic acid intake in women aged 20-35 years, and about double that in people aged 40-65. Every doubling of serum folate concentration roughly halves the risk of an NTD. These two effects can be combined to predict the reduction in risk according to intake of extra folic acid and background serum folate concentration. Such results predict that the preventive effect is greater in women with low serum folate than in those with higher concentrations. The results have also been used to predict direct observations from large randomised trials and the effect of food fortification. From a typical western background serum folate of 5 ng/mL, about 0.2 mg/day (the US level of folic acid fortification) would be expected to reduce NTDs by about 20%; a similar effect can be expected from the current British recommendation (0.24 mg/day). An increase of 0.4 mg/day would reduce risk by about 36%, of 1 mg/day by 57%, and taking a 5-mg tablet daily would reduce risk by about 85%. INTERPRETATION: Folic acid fortification levels should be increased. Additionally women planning a pregnancy should take 5 mg folic acid tablets daily, instead of the 0.4 mg dose presently recommended.

Adult↗
PubMed1988

Effect of antacid and H2 receptor antagonists on the intestinal absorption of folic acid.

Intestinal folic acid transport is a saturable process with a pH optimum of 5.5 to 6.0. Because of the possible effects of antacids and acid-lowering drugs on the pH of the proximal small intestine, the influence of these drugs on folic acid absorption was studied by using tritium-labeled pteroylmonoglutamic acid (PGA) in 30 subjects (21 women, nine men) of 56 to 89 years of age. Both cimetidine and an antacid containing aluminum and magnesium hydroxide reduced folate absorption from a liquid formula meal (p less than 0.01, p less than 0.001, respectively). Although ranitidine also caused a fall in folic acid absorption from the liquid meal, the change was not statistically significantly different from when PGA was given with the meal alone. Both histamine receptor antagonists tended to maintain a high intraluminal pH in the proximal small intestine after meals, which in part could explain the inhibition of folate absorption. However, neither drug was found to chemically interact with folic acid, and neither drug inhibited the dihydrofolate reductase. The antacid was found to precipitate folic acid at a pH of greater than 4.0, thus removing it from the aqueous phase. This appears to be the explanation for the lowered folate absorption in the presence of antacid. Although the effects of these drugs on reducing folic acid absorption were relatively small, such reductions could become clinically significant in chronic antacid or H2 receptor antagonist use or intensive antacid or H2 receptor antagonist use by individuals eating diets that are marginal in folate content.

Aged↗
PubMed2005

Quantitation of N2-[1-(1-carboxy)ethyl]folic acid, a nonenzymatic glycation product of folic acid, in fortified foods and model cookies by a Stable isotope dilution assay.

A stable isotope dilution assay (SIDA) for the quantitation of N(2)-[1-(carboxy)ethyl]folic acid (CEF) has been developed by using [(2)H(4)]CEF as the internal standard. After sample cleanup by anion exchange chromatography, the three-dimensional specifity of liquid chromatography-tandem mass spectrometry enabled unequivocal determination of the nonenzymatic glycation product of folic acid (FA). When CEF was added to cornstarch, the detection limit for CEF was found to be 0.4 microg/100 g, and a recovery of 98.5% was determined. In analyses of cookies, the intra-assay coefficient of variation was 8.0% (n = 5). Application of the SIDA to commercial cookies produced from wheat flour fortified with FA revealed CEF contents of up to 7.1 microg/100 g, which accounted for approximately 10-20% of the cookies' FA content. In baby foods, multivitamin juices, and multivitamin sweets, however, CEF was not detectable. Further studies on CEF formation during baking of cookies made from fortified flour and different carbohydrates revealed that fructose was most effective in generating CEF followed by glucose, lactose, and sucrose with 12.5, 3.9, 2.5, and 2.5 microg/100 g of dry mass, respectively. During baking, approximately 50% of FA was retained for both monosaccharides fructose and glucose, and 77% as well as 85% of its initial content was retained for the disaccharides lactose and sucrose, respectively. Of the degraded amount of FA, CEF comprised 28% for fructose as well as 18, 12, and 8% for sucrose, lactose, and glucose, respectively. Therefore, CEF can be considered an important degradation product of FA in baked foods made from fructose. To retain a maximum amount of FA, products should rather be baked with sucrose than with reducing carbohydrates.

Deuterium↗
PubMed1964

INSECT FERTILITY: INHIBITION BY FOLIC ACID DERIVATIVES.

Folic acid antagonists inhibited oviposition by screw-worm flies [Cochliomyia hominivorax (Coquerel); Diptera: Calliphoridae]. Fertility was unaltered when sufficient folic acid was administered simultaneously, or it was partly restored spontaneously about 2 weeks after treatment. Folic acid antagonists principally affected only maturing eggs at any age, rather than those already matured.

Aminopterin↗
PubMed1983

Ascorbic acid, vitamin A, folic acid, and amino acids in blood of patients with hemophilia.

Blood levels of ascorbic acid, vitamin A, folic acid, and amino acids were studied in patients at the South Texas Comprehensive Hemophilia Center, San Antonio, TX. The mean plasma ascorbic acid level in hemophiliacs was significantly lower than controls (p less than 0.0001). This was observed despite a dietary ascorbic acid intake in excess of 66% of the Recommended Dietary Allowances (RDA). However, those subjects receiving specific factor replacement therapy at home and consuming at least 66% RDA of ascorbic acid maintained a mean plasma ascorbic acid level not significantly less than controls. Hemophilic subjects not on home therapy, on the other hand, had a mean plasma ascorbic acid level significantly below that of controls while receiving optimal dietary ascorbic acid. With prompt adequate medical care of bleeding episodes and with optimal nutrition, the demand for ascorbic acid needed for tissue repair in hemophilic patients may be lessened. Hemophiliacs had mean serum vitamin A, mean serum folate, and mean red cell folate levels that were not significantly different from controls. Significantly higher mean plasma arginine and lower, but not significantly lower, mean plasma ornithine levels were found in hemophilic subjects, suggesting altered arginase activity.

Adolescent↗
PubMed1986

Interaction of milk xanthine oxidase with folic acid. Inhibition of milk xanthine oxidase by folic acid and separation of the enzyme into two fractions on Sepharose 4B/folate gel.

Inhibition of xanthine oxidase by folic acid was reexamined after complete removal of the contaminant which was responsible for time-dependent inactivation (Lewis, A. S., Murphy, L., Mcalla, C., Fleary, M., and Purcell, S. (1984) J. Biol. Chem. 259, 12-15; Spector, T., and Ferone, R. (1984) J. Biol. Chem. 259, 10784-10786). From turnover experiments using stopped flow equipment with a limited amount of xanthine and excess oxygen, and from kinetic analyses with an oxygen electrode, folic acid was found to be an inhibitor of xanthine oxidase. The inhibition was competitive with xanthine with a Ki value of 4.2 X 10(-5) M. From the behavior of the enzyme in affinity chromatography using a Sepharose 4B/folate column, folic acid was also confirmed to be a competitive inhibitor of xanthine oxidase. When enzyme which had been pretreated with oxipurinol was applied to the affinity column, two fractions of xanthine oxidase were separated. The first fraction was found to contain the fully active form (double-active dimers) from the analyses of spectral changes on addition of xanthine, oxipurinol titration, and ESR slow signal, whereas the second fraction was assumed to contain mixed dimers and double-inactive dimers. The ratio of the content of the first fraction to that of the second fraction supports the hypothesis that there are three enzyme species and that there is no interaction either in catalytic activity or in sulfuration or desulfuration reactions between the two subunits.

Animals↗
PubMed1995

[Intake of folic acid in the total daily diet--effect of food preparation on its folic acid content].

The folic acid content of total daily diet was determined by means of high-performance liquid chromatography (HPLC). The contents of tetrahydrofolic acid (THF), 5-methyl-THF and 5-formyl-THF were differentiated. The mean of the folic acid content of the total daily diet samples determined analytically was 205 +/- 60 micrograms and the mean of the individual ingredients of the samples was 401 +/- 78 micrograms, which implies that about 50% of folic acid is destroyed by common household food preparation methods. If the contents of pteroylglutamic acid (PteGlu) and 10-formyl-PteGlu (which cannot be determined analytically) are added, it can be assumed that the folic acid content with only be reduced by about 40%. THF and 5-methyl-THF proved to be less stable than 5-formyl-THF. The monoglutamate portion of the total folat content was higher in the total diet samples than in the individual foodstuffs as a consequence of the action of the enzyme "deconjugase" which is released when the matrix of food-stuffs is destroyed.

Chromatography, High Pressure Liquid↗
PubMed1961

Conventional voltage electrophoresis for formiminoglutamic-acid determination in folic acid deficiency.

A new method for the determination of urinary formiminoglutamic acid (FIGLU) using conventional electrophoresis at 200 to 500 v. on cellulose acetate strips is reported. Experience in 166 determinations on 137 patients shows the method to be a simple, practical, and apparently sensitive one for the determination of FIGLU in the urine. Results of the application of the measurement of urinary FIGLU with histidine loading as a test for folic acid deficiency are also reported.

Cellulose↗
PubMed1975

Binding of folic acid to serum proteins. V. Tritiated folic acid in the liver.

Sephadex G-200 chromatographies of the liver cell sap of rabbits, 1, 3 and 6 days after an injection of 3H-folic acid activity (FAA) into the circulation, were used in an attempt to study the binding of this labelled FAA to liver proteins. The labelled FAA was quickly accumulated in the liver, and in the cell sap it was grouped chromatographically to two maxima, which corresponded to the two maxima of microbiological FAA (L. casei). The maxima were eluated in the chromatography together with cell sap proteins. The possible coupling of FAA to proteins in the liver is discussed.

Animals↗