Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FOLIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

The importance of folic acid.

Folic acid is necessary for cell development; for the metabolism of specific biochemical reactions in the body, such as the conversion of homocysteine to methionine; and for the metabolism of specific anticonvulsant drugs. Folic acid has an interrelationship with vitamin B12. A deficiency of folate increases the risk of NTDs, as well as contributing to hyperhomocystinemia, a condition associated with increased cardiovascular disease and NTDs. For the prevention of NTDs, it is recommended that a woman of childbearing age consume a daily folate intake of 400 micrograms; however, the average dietary folate intake is half that amount, and the FDA folate fortification of cereal grains adds only 100 micrograms daily. The woman in her childbearing years does not meet the recommendation with dietary and food fortification. Periconceptional folic acid supplementation is essential, because the neural tube closes 23 to 27 days after conception. Therefore, a multiple vitamin containing folic acid is the practical solution at present if the food fortification is not increased. The bioavailability of folate in the vitamin preparation is approximately double that of dietary folate. Most preparations contain 400 micrograms of folic acid, and if the woman took a multiple vitamin (400 micrograms of folate) in addition to her diet (230 micrograms of folate), she would not exceed 1000 micrograms (1 mg) daily, which is considered the upper limit of daily folate ingestion by dietary fortification and supplementation before the masking of vitamin B12 becomes a concern. However, in this group of patients, pernicious anemia is rare. Regarding cardiovascular disease in men and women, there are no long-term studies showing the benefit of folic acid in reducing the homocysteine level. At present, there are only estimations. However, they should not be ignored. Although it is not the current standard of practice, adding a multiple vitamin containing folic acid to the regimen of men and women starting anticonvulsant medication should be considered in order to prevent the folate lowering observed with such commonly used drugs as PHT and carbamazepine. Women in childbearing years should be on a folic acid supplement when taking an anticonvulsant drug. In general, it appears that all men and women would benefit from increased folate intake. This can be accomplished through vitamin supplementation when there is compliance. However, if the food fortification for folate is increased in the future, then the issue of vitamin supplementation will have to be readdressed.

Cardiovascular Diseases↗
PubMed2000

Fortifying food with folic acid.

Folic acid supplementation may help prevent the following three common and important disorders: neural tube defect pregnancies, ischemic heart disease and strokes, and possibly colon cancer. Several studies have irrefutably established that folic acid supplementation in proper doses reduces neural tube defect pregnancies. Fortified food would be the most reliable way to address this health issue. Several epidemiologic reports have established a close link between hyperhomocysteinemia and ischemic heart disease. This is supported by evidence obtained from genetic defects leading to elevated plasma levels of homocysteine. There is reasonable evidence to conclude that hyperhomocysteinemia is the actual cause of excessive cardiac diseases. Again, folic acid supplementation in proper doses could potentially reduce ischemic heart disease by 40% There is also some evidence to suggest that folic acid treatment reduces the incidence of colon cancer. The reduction in all three health problems is dependent upon the dose of folic acid administered. The levels needed are rarely supplied by the daily food intake, even under ideal conditions, although breakfast cereals address this problem at least in part. It is proposed that flour be fortified because it is a food product heavily used by most people, and that governmental agencies should oversee such programs because they are responsible for setting public health policies.

Bread↗
PubMed2004

5-Methyltetrahydrofolic acid and folic acid measured in plasma with liquid chromatography tandem mass spectrometry: applications to folate absorption and metabolism.

We describe a liquid chromatography (LC) tandem mass spectrometry (MS-MS) method for the determination of 5-methyltetrahydrofolic acid (5-methylTHF) and folic acid concentrations and enrichments in human plasma. It was used to study absorption and initial metabolism in five volunteers with two simultaneously administered oral test doses ([(13)C(6)]folic acid in capsules and [(2)H(2)]folic acid in a drink). [(13)C(5)]5-methylTHF and [(2)H(4)]folic acid were used as internal standards. Plasma samples (2 ml) were purified using folate binding protein affinity columns, followed by a concentration step. After LC separation, folates were detected using positive electrospray ionization MS-MS under multiple reaction monitoring conditions. Calibrations were linear for 5-methylTHF over the range 1.2 x 10(-11) (=limit of detection) to 3.2 x 10(-7)mol/L and for folic acid over the range 5 x 10(-10) (=limit of detection) to 4.5 x 10(-8)mol/L. For 5-methylTHF concentration in plasma, intraassay coefficient of variation was within 8.6% (and for unlabeled 5-methylTHF it was within 2.8%) and interassay coefficient of variation was within 9.0%. For folic acid concentrations these coefficient of variations were within 7.5% and within 6.5%, respectively. The [(13)C(6)] and [(2)H(2)] isotopomers of folic acid and 5-methylTHF were measured in the plasma of each volunteer for 8h. After accounting for the time delay due to capsule opening, the modeling results showed no significant differences in absorption time, first pass effect, and elimination rate in the folic acid test doses in capsule or drink. We conclude that LC-MS-MS offers increased sensitivity for quantification of plasma concentrations and enrichments of 5-methylTHF and folic acid and is applicable to stable-isotope studies in humans.

Administration, Oral↗
PubMed2001

Folic acid.

Folic acid is an essential nutrient from the B complex group of vitamins. Folate, as a cofactor, is involved in numerous intracellular reactions, and this is reflected in the various derivatives that have been isolated from biological sources. Folic acid is involved in single carbon transfer reactions and serves as a source of single carbon units in different oxidative states. The processes involved in the absorption, transport, and intracellular metabolism of this cofactor are complex. Much of folate is bound tightly to enzymes, indicating that there is not excess of this cofactor and that its cellular availability is protected as well as being strictly regulated. In animals, the liver controls the supply of folate through first pass metabolism, biliary secretion, enterohepatic recirculation, as well as through senescent erythrocyte recycling. Deficiencies of folate can occur for many reasons, including reduced intake, increased metabolism, and/or increased requirements as well as through genetic defects. The effects of folate deficiency include hyperhomocysteinemia, megaloblastic anemia, and mood disorders. Folate deficiency has also been implicated in disorders associated with neural tube defects. Supplementation of grain products such as cereals has been undertaken in several countries as a cost-effective means of reducing the prevelance of neural tube defects. Recently, common polymorphisms have been discovered in several genes associated with folate pathways that may play a role in diseases associated with folate deficiency, particularly mild folate deficiency.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1998

Effect of trans-retinoic acid and folic acid on apoptosis in human gastric cancer cell lines MKN-45 and MKN-28.

Induction of apoptosis has been implicated as an anticarcinogenic mechanism of both folic acid and retinoic acid. The ability of retinoic acid or folic acid to induce gastric cancer cell apoptosis was investigated in the human gastric cancer cell lines MKN-45 and MKN-28, and DNA fragmentation was studied in situ by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and DNA agarose gel electrophoresis. The rates of apoptosis in both the poorly differentiated MKN-45 and the well differentiated MKN-28 cell line were less than 5% after treatment with either retinoic or folic acid. Apoptosis may be induced by the administration of retinoic acid or folic acid, and the apoptosis indices of MKN-45 and MKN-28 cells were related to the doses of these drugs. The induction of gastric cancer cell apoptosis may play a role in the anticarcinogenic effect of retinoic acid and folic acid, both of which are potential agents for the treatment of human gastric cancer.

Antineoplastic Agents↗
PubMed1985

Antagonism of sulfadoxine and pyrimethamine antimalarial activity in vitro by p-aminobenzoic acid, p-aminobenzoylglutamic acid and folic acid.

The activity of pyrimethamine and sulfadoxine against two strains of Plasmodium falciparum has been studied in vitro by a radioisotopic technique. Low level antagonism of pyrimethamine resulted from the inclusion of p-aminobenzoic acid, p-aminobenzoylglutamic acid or folic acid in the test medium. Sulfadoxine activity was antagonised slightly by p-aminobenzoic but not by p-aminobenzoylglutamic acid, and antagonised markedly by folic acid at concentrations above 4 X 10(-8) M. At 10(-7) M folic acid, a concentration lower than that of normal RPMI medium 1640, sulfadoxine activity was reduced 7000 to 9000-fold in comparison with controls. These results are of importance in terms of the utilisation of folates by P. falciparum, the susceptibility of the parasite to antifolate drugs and the in vitro determination of parasite susceptibility.

4-Aminobenzoic Acid↗
PubMed1976

Portal and peripheral plasma folates after ingestion of folic acid.

Folic acid in amounts of 2 mumol (0.88 mg) was given by mouth to four patients who had undergone portal vein catheterization. All had normal liver function. The increase in folates in plasma obtained from portal and peripheral veins was followed for three hours with the use of L. casei and S. faecalis as test organisms. The results lend support to the assumption that the liver is the main site of methylation of folic acid when given in physiological amounts.

Adult↗
PubMed1979

Synthesis of aza homologues of folic acid.

Folic acid analogues containing an additional nitrogen atom between the phenyl ring and the carbonyl group of the side chain were synthesized. None of the compounds showed significant inhibitory activity against human lymphoblastic leukemia cells (CCRF-CEM) in culture or against Lactobacillus casei (ATCC 7469) growth. Against L1210 leukemia in mice, the aza homologue of folic acid, 4, and the aspartic acid analogue, 14, showed no increase in life span over control animals. These compounds were more toxic in vivo than the corresponding methotrexate analogues. Compound 4 supported the growth of Streptococcus faecium (ATCC 8043), and its tetrahydro derivative supported the growth of Pediococcus cerevisiae (ATCC 8081). These results strongly suggest that 4 can substitute for folate derivatives as cofactors for serine transhydroxymethylase, thymidylate synthetase, and dihydrofolate reductase.

Animals↗
PubMed1987

Optimal concentration of p-aminobenzoic acid and folic acid in the in vitro assay of antifolates against Plasmodium falciparum.

In vitro tests for Plasmodium falciparum sensitivity to pyrimethamine, sulfadoxine, and both drugs in combination were performed in four kinds of culture medium, each differing in p-amino benzoic acid (PABA) and folic acid concentrations. Results of the tests using pyrimethamine-sensitive and pyrimethamine-resistant isolates indicated that drug activity was reduced proportionally to the concentrations of these two growth factors in the medium. The optimal concentrations of PABA and folic acid for parasite growth and drug susceptibility, as evaluated by microscopic examination and by the extent of incorporation of radioactive 14C-pyrimethamine and 14C-sulfadoxine, were 10 ng/ml and 2 ng/ml, respectively. Depletion of PABA and folic acid from the medium had no effect on drug-resistant parasites but multiplication of drug-sensitive isolates was markedly reduced. Medium containing 0.5 ng/ml PABA and 10 ng/ml folic acid was the best for parasite growth regardless of the degree of drug sensitivity. Results obtained by using this medium agreed most closely with results from in vivo observations.

4-Aminobenzoic Acid↗
PubMed2003

Determination of 5-methyltetrahydrofolic acid and folic acid in citrus juices using stable isotope dilution-mass spectrometry.

A stable isotope liquid chromatography-mass spectrometry (LC-MS) method was developed for the quantitative determination of 5-methyltetrahydrofolic acid (5-MTHFA) and folic acid in a variety of commercial citrus juices. Folates were extracted from juices, and the polyglutamyl side chain of 5-MTHFA was cleaved to the monoglutamate form using rat plasma conjugase. The folates were purified on a Bond-Elut column and analyzed by LC-MS with electrospray ionization. The analytes were quantified using the (13)C(5) analogues of 5-MTHFA and folic acid as internal standards. The relative standard error of the method was 3.35% based on replicate analyses (n = 4). This method was then applied to the determination of 5-MTHFA and folic acid in a variety of citrus juices obtained from local supermarkets. It was observed that although both "store" brands and "national" brands of fresh (nonfrozen) juices contained similar concentrations of 5-MTHFA, the "store" brands of fresh juices had on average >5-fold the amount of folic acid compared to the "national" brands. In addition, the "total" folate concentrations were generally below values listed on the food label.

Beverages↗
PubMed1992

Concentrations of the water-soluble vitamins thiamin, ascorbic acid, and folic acid in serum and cerebrospinal fluid of healthy individuals.

Thiamin, thiamin monophosphate, ascorbic acid, and folic acid were determined in serum and cerebrospinal fluid (CSF) in 31 outpatients who underwent a myelography because of back-pain. All subjects were otherwise healthy. The CSF concentration (mean +/- SD) was 8.6 +/- 3.9 nmol thiamin/L, 16.9 +/- 8.3 nmol thiamin monophosphate/L, 133 +/- 58.8 mumol ascorbic acid/L, and 44.9 +/- 13.2 nmol folic acid/L. The CSF-serum ratio was 2.1 +/- 0.8 for thiamin, 8.3 +/- 4.3 for thiamin monophosphate, 3.0 +/- 1.4 for ascorbic acid, and 3.3 +/- 0.8 for folic acid; the amount in CSF was significantly higher than in serum for each compound. These results support the existence of a saturated transport mechanism of water-soluble vitamins from serum into CSF for thiamin monophosphate, ascorbic acid, and folic acid. However, low CSF concentrations are correlated with low serum concentrations for the three vitamins. High serum concentrations should therefore be advocated to ensure high CSF concentrations.

Adult↗