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Clinical Pharmacokinetics Aug 2010There is a large body of evidence to suggest that improving periconceptional folate status reduces the risk of neonatal neural tube defects. Thus increased folate intake... (Comparative Study)
Comparative Study Review
There is a large body of evidence to suggest that improving periconceptional folate status reduces the risk of neonatal neural tube defects. Thus increased folate intake is now recommended before and during the early stages of pregnancy, through folic acid supplements or fortified foods. Furthermore, there is growing evidence that folic acid may have a role in the prevention of other diseases, including dementia and certain types of cancer. Folic acid is a synthetic form of the vitamin, which is only found in fortified foods, supplements and pharmaceuticals. It lacks coenzyme activity and must be reduced to the metabolically active tetrahydrofolate form within the cell. L-5-methyl-tetrahydrofolate (L-5-methyl-THF) is the predominant form of dietary folate and the only species normally found in the circulation, and hence it is the folate that is normally transported into peripheral tissues to be used for cellular metabolism. L-5-methyl-THF is also available commercially as a crystalline form of the calcium salt (Metafolin(R)), which has the stability required for use as a supplement. Studies comparing L-5-methyl-THF and folic acid have found that the two compounds have comparable physiological activity, bioavailability and absorption at equimolar doses. Bioavailability studies have provided strong evidence that L-5-methyl-THF is at least as effective as folic acid in improving folate status, as measured by blood concentrations of folate and by functional indicators of folate status, such as plasma homocysteine. Intake of L-5-methyl-THF may have advantages over intake of folic acid. First, the potential for masking the haematological symptoms of vitamin B(12) deficiency may be reduced with L-5-methyl-THF. Second, L-5-methyl-THF may be associated with a reduced interaction with drugs that inhibit dihydrofolate reductase.
Topics: Adult; Animals; Biological Availability; Drug Interactions; Female; Folic Acid; Folic Acid Antagonists; Humans; Intestinal Absorption; Male; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Pregnancy; Tetrahydrofolate Dehydrogenase; Tetrahydrofolates; Young Adult
PubMed: 20608755
DOI: 10.2165/11532990-000000000-00000 -
The International Journal of... 1988
Review
Topics: Animals; Carrier Proteins; Chemical Phenomena; Chemistry; Folate Receptors, GPI-Anchored; Folic Acid; Folic Acid Antagonists; Folic Acid Deficiency; Humans; Nutritional Requirements; Receptors, Cell Surface
PubMed: 3280358
DOI: 10.1016/0020-711x(88)90476-4 -
European Journal of Pharmaceutical... Oct 2016Folic acid is a small molecule, also known as vitamin B9. It is an essential compound involved in important biochemical processes. It is widely used as a vector for... (Review)
Review
Folic acid is a small molecule, also known as vitamin B9. It is an essential compound involved in important biochemical processes. It is widely used as a vector for targeted treatment and diagnosis especially in cancer therapeutics. Nevertheless, not many authors address the problem of folic acid degradation. Several researchers reported their observations concerning its denaturation, but they generally only took into account one parameter (pH, temperature, light or O2etc.). In this review, we will focus on five main parameters (assessed individually or in conjunction with one or several others) that have to be taken into account to avoid the degradation of folic acid: light, temperature, concentration, oxygen and pH, which are the most cited in the literature. Scrupulous bibliographic research enabled us to determine two additional degradation factors that are the influence of singlet oxygen and electron beam on folic acid stability, which are not considered as among the prime factors. Although these two factors are not commonly present as compared to the others, singlet oxygen and electron beams intervene in new therapeutic technologies and must be taken in consideration for further applications such photodynamic or X-rays therapies.
Topics: Drug Stability; Folic Acid; Hydrogen-Ion Concentration; Oxygen; Temperature; Ultraviolet Rays
PubMed: 27575880
DOI: 10.1016/j.ejps.2016.08.045 -
Nutrition Reviews Mar 1996The relationship of folic acid to neural tube defects has provided us with one of the richest case studies in nutrition science policy of this half century. The concepts... (Review)
Review
The relationship of folic acid to neural tube defects has provided us with one of the richest case studies in nutrition science policy of this half century. The concepts of nutritional adequacy in the periconceptual period, the power of well-designed and controlled intervention trials, the challenges of altering the intake of a critical nutrient, the risks and benefits of food fortification, proper targeting with supplementation, and the effectiveness of achieving dietary change are all elements of this case study that we will continue to explore throughout the pages of this journal in the months ahead.
Topics: Female; Folic Acid; Food, Fortified; Humans; Neural Tube Defects; Nutrition Policy; Pregnancy; United States; United States Food and Drug Administration
PubMed: 8935221
DOI: 10.1111/j.1753-4887.1996.tb03879.x -
Drug Intelligence & Clinical Pharmacy Apr 1984The nutrient-drug interaction between folate and phenytoin is a two-way interaction. Folate deficiency resulting from long-term phenytoin therapy is a common occurrence,... (Review)
Review
The nutrient-drug interaction between folate and phenytoin is a two-way interaction. Folate deficiency resulting from long-term phenytoin therapy is a common occurrence, but progression of the deficiency to a megaloblastic anemia is rare. However, there are data to suggest nonanemic folate deficiency may be detrimental to the patient. Several mechanisms have been proposed to explain the ability of phenytoin to deplete body folate. The supplementation of folic acid to folate-deficient patients taking phenytoin has been shown to result in lowered serum concentrations of phenytoin, and possibly loss of control of the seizure disorder. Folate appears to be associated with the hepatic metabolism of phenytoin, although the effect of folic acid supplementation on phenytoin elimination kinetics is suggested to be individualized.
Topics: Folic Acid; Folic Acid Deficiency; Humans; Nervous System Diseases; Phenytoin; Tissue Distribution
PubMed: 6370643
DOI: 10.1177/106002808401800404 -
Human Psychopharmacology Oct 2004The associations of folic acid and its derivatives with depressive disorder are reviewed. Derivatives of folic acid such as biopterins and the synthesis of S-adenosyl... (Review)
Review
The associations of folic acid and its derivatives with depressive disorder are reviewed. Derivatives of folic acid such as biopterins and the synthesis of S-adenosyl methionine (SAM) are known either to be associated with improvement or to have a direct therapeutic effect in depressive disorder. Studies investigating plasma and red cell folic acid levels in depressed patients have used differing assay methodologies which make comparison difficult, although there is substantial evidence of the association between depressive disorder (particularly severe depression) and low folic acid levels. The few studies available suggest folic acid has either antidepressant properties or can act as an augmenting agent for standard antidepressant treatment. A recently discovered genetic variant (5,10 MTHFR) leading to altered folic acid metabolism may explain why some individuals are vulnerable to the effects of folic acid deficiency, despite adequate intake. The links of 5,10 MTHFR to the presence of depressive disorder in the community are being investigated.
Topics: Brain; Depressive Disorder; Dietary Supplements; Folic Acid; Homocysteine; Humans
PubMed: 15378677
DOI: 10.1002/hup.614 -
Nihon Rinsho. Japanese Journal of... Oct 1999One-carbon derivatives of tetrahydrofolate, the coenzyme form of the vitamin folic acid, play a key role in DNA synthesis and cell replication, through their involvement... (Review)
Review
One-carbon derivatives of tetrahydrofolate, the coenzyme form of the vitamin folic acid, play a key role in DNA synthesis and cell replication, through their involvement in the biosynthesis of purine nucleotides and the amino acids. Although the most conspicuous symptom of folic acid deficiency is pernicius anemia, it has been observed that the lack of folate intake during the pregnancy induce the incidence of neural tube defects such as apina bifida. Recently, it has been reported that clinical progression of coronary heart disease and cerebral peripheral vascular disease occurred at a high rate in hyperhomocysteinemia with low folate content in plasma. Consequently, the nutritional importance of folate has been increasingly recognized.
Topics: Female; Folic Acid; Folic Acid Deficiency; Humans; Pregnancy
PubMed: 10540871
DOI: No ID Found -
Obstetrical & Gynecological Survey Apr 2011Folic acid is one of the B complex vitamins and is now recognized as a major component of the periconceptional care of women in the reproductive age group. Deficiency of... (Review)
Review
UNLABELLED
Folic acid is one of the B complex vitamins and is now recognized as a major component of the periconceptional care of women in the reproductive age group. Deficiency of folic acid can lead to neural tube defects in the fetus and megaloblastic anemia in the mother. Due to its lower bioavailability from natural foods, many countries have adopted mandatory folic acid food fortification programs. Although these programs have been a public health triumph in reducing the burden of neural tube defects, there have been growing concerns about the role played by folic acid supplementation in the rising colon cancer rates over the past decade. The majority of the evidence available to date is reassuring, and until further long-term population as well as laboratory studies are completed, folic acid will continue to play a vital role in early pregnancy care. It is important for healthcare professionals to be aware of the recent evidence that has accumulated, suggesting higher folic acid requirements in certain groups of women and offer correct advice on the use of folic acid supplements. This review looks at some of the existing evidence on folic acid supplementation and summarizes the recommendations on the use of folic acid supplements by obstetricians, family physicians, and others providing prenatal care.
TARGET AUDIENCE
Obstetricians and Gynecologists, Family physicians.
LEARNING OBJECTIVES
After completing this CME activity, physicians should be better able to evaluate the need for folic acid supplementation in various patient groups to lower the risk of neural tube defects due to folate deficiency; recommend common, natural and fortified food sources rich in folic acid; and distinguish the effects of folate deficiency in the mother and fetus.
Topics: Adenoma; Animals; Colorectal Neoplasms; Dietary Supplements; Female; Folic Acid; Folic Acid Deficiency; Humans; Neural Tube Defects; Pregnancy; Prenatal Care
PubMed: 21756406
DOI: 10.1097/OGX.0b013e318223614c -
Practical Neurology May 2024
Topics: Humans; Epilepsy; Folic Acid; Female; Pregnancy; Anticonvulsants
PubMed: 38527794
DOI: 10.1136/pn-2023-003829 -
Ciba Foundation Symposium 1994The results of the MRC Vitamin Study have established the specific role of folic acid in the prevention of neural tube defects. Folic acid supplementation (4 mg/day) at... (Review)
Review
The results of the MRC Vitamin Study have established the specific role of folic acid in the prevention of neural tube defects. Folic acid supplementation (4 mg/day) at the time of conception reduced the recurrence rate by about 70%. Evidence from observational studies and the Hungarian randomized trial (that used 0.4-0.8 mg/day supplemental folic acid) indicates that a similar level of prevention can be achieved among women who have not already had an affected pregnancy and that this may be achieved with a lower dose of folic acid. The medical implications of these results are important. (1) Women planning a pregnancy should take folic acid supplements. (2) Because a large proportion of pregnancies are unplanned and many of those that are planned will occur in women who will not have taken folic acid supplements, a complementary general public health strategy is needed, based on dietary advice and food fortification designed to achieve the benefit with adequate safety. (3) Any public health prevention strategy needs to be monitored for efficacy and possible harm. (4) Research is needed on the dose-response relationship between folic acid and neural tube defect prevention and the mechanism of action.
Topics: Dose-Response Relationship, Drug; Female; Folic Acid; Humans; Neural Tube Defects; Pregnancy
PubMed: 8005025
DOI: 10.1002/9780470514559.ch12