5-methyltetrahydrofolate and Folic-Acid-Deficiency

1. Folate, an essential micronutrient, is a critical cofactor in one-carbon metabolism. Mammals cannot synthesize folate and depend on supplementation to maintain normal levels. Low folate status may be caused by low dietary intake, poor absorption of ingested folate and alteration of folate metabolism due to genetic defects or drug interactions. 2. Folate deficiency has been linked with an increased risk of neural tube defects, cardiovascular disease, cancer and cognitive dysfunction. Most countries have established recommended intakes of folate through folic acid supplements or fortified foods. External supplementation of folate may occur as folic acid, folinic acid or 5-methyltetrahydrofolate (5-MTHF). 3. Naturally occurring 5-MTHF has important advantages over synthetic folic acid - it is well absorbed even when gastrointestinal pH is altered and its bioavailability is not affected by metabolic defects. Using 5-MTHF instead of folic acid reduces the potential for masking haematological symptoms of vitamin B12 deficiency, reduces interactions with drugs that inhibit dihydrofolate reductase and overcomes metabolic defects caused by methylenetetrahydrofolate reductase polymorphism. Use of 5-MTHF also prevents the potential negative effects of unconverted folic acid in the peripheral circulation. 4. We review the evidence for the use of 5-MTHF in preventing folate deficiency.

Topics: Animals; Dietary Supplements; Folic Acid; Folic Acid Deficiency; Food, Fortified; Humans; Leucovorin; Methylenetetrahydrofolate Reductase (NADPH2); Polymorphism, Genetic; Tetrahydrofolates

Women have higher requirements for folate during pregnancy. An optimal folate status must be achieved before conception and in the first trimester when the neural tube closes. Low maternal folate status is causally related to neural tube defects (NTDs). Many NTDs can be prevented by increasing maternal folate intake in the preconceptional period. Dietary folate is protective, but recommending increasing folate intake is ineffective on a population level particularly during periods of high demands. This is because the recommendations are often not followed or because the bioavailability of food folate is variable. Supplemental folate [folic acid (FA) or 5-methyltetrahydrofolate (5-methylTHF)] can effectively increase folate concentrations to the level that is considered to be protective. FA is a synthetic compound that has no biological functions unless it is reduced to dihydrofolate and tetrahydrofolate. Unmetabolized FA appears in the circulation at doses of >200 μg. Individuals show wide variations in their ability to reduce FA. Carriers of certain polymorphisms in genes related to folate metabolism or absorption can better benefit from 5-methylTHF instead of FA. 5-MethylTHF [also known as (6S)-5-methylTHF] is the predominant natural form that is readily available for transport and metabolism. In contrast to FA, 5-methylTHF has no tolerable upper intake level and does not mask vitamin B12 deficiency. Supplementation of the natural form, 5-methylTHF, is a better alternative to supplementation of FA, especially in countries not applying a fortification program. Supplemental 5-methylTHF can effectively improve folate biomarkers in young women in early pregnancy in order to prevent NTDs.

Topics: Biomarkers; Female; Fetal Blood; Folic Acid; Folic Acid Deficiency; Humans; Infant, Newborn; Methylenetetrahydrofolate Reductase (NADPH2); Neural Tube Defects; Nutritional Requirements; Polymorphism, Single Nucleotide; Pregnancy; Risk Factors; Tetrahydrofolates

Proper folate supplementation is required in order to ensure proper folate concentration in the organism, and consequently to prevent the development of numerous complications in general population and pregnant women. Metafolin (stable calcium salt of L-5-methyltetrahydrofolate acid, L-5-MTHF) is the most active form of reduced folate circulating in plasma, which directly enters the metabolic process of folate. After administration metafolin shows optimum absorption, comparable or higher bioavailability as well as physiological activity when compared to folic acid. Metafolin supplementation is effective in decreasing plasma homocysteine, as well as increasing folate in plasma and erythrocytes, in pregnant and breastfeeding women or those who wish to conceive. In addition, metafolin administration omits the multistage process of reduction before entering the folate cell cycle, as well as a possible deficiency of activity of enzymes participating in the reduction of folate process in the intestine epithelium (DHFR and MTHFR enzymes). So far no potential adverse and toxic effects of metafolin management have been reported. The published findings require confirmation in larger groups of patients and an additional analysis of the presence of particular genotypes of 677C > T polymorphism of the MTHFR gene. Analysis of the recent literature reposts suggests that metafolin could be an effective and safe alternative to folic acid supplementation and could effectively prevent complications in pregnancy and series birth defects in fetuses and newborns.

Topics: Dietary Supplements; Female; Folic Acid; Folic Acid Deficiency; Humans; Neural Tube Defects; Pregnancy; Pregnancy Complications; Prenatal Care; Tetrahydrofolates; Vitamins; Women's Health

The use of two antidepressants from the initiation of treatment in major depressive disorder has been investigated in several recent studies and forms a paradigm shift in the pharmacotherapy of the condition. Several, but not all, trials have claimed improved response and remission rates with the combinations as opposed to monotherapy. The use of folate preparations (folic and folinic acid and l-meth-ylfolate) have shown effective augmentation of antidepressant response in a variety of controlled and open-label settings in patients with normo- and hypofolatemic status. Several recent trials using L-methylfolate, the active and more bioavailable form of folic acid, have shown promising adjunctive use with a well-tolerated adverse event profile.

Topics: Antidepressive Agents; Depressive Disorder, Major; Drug Therapy, Combination; Folic Acid; Folic Acid Deficiency; Humans; Leucovorin; Tetrahydrofolates; Treatment Outcome

Over the past decade, a syndrome consisting of low folate values in the cerebrospinal fluid (CSF) has been described. The syndrome has been associated with both genetic and acquired conditions that affect folate transport and metabolism and can result in severe neurological disorders. There is a wide range of underlying pathophysiological mechanisms, but a common feature in most patients is a good clinical response to folate therapy, especially when the syndrome is diagnosed early. In this review, we focus our attention on the genetic diseases leading to profound cerebral folate deficiency (CFD) and review current clinical, metabolic and therapeutic approaches.

Topics: Betaine; Cerebral Cortex; Folic Acid; Folic Acid Deficiency; Genetic Predisposition to Disease; Humans; Intestinal Absorption; Leucovorin; Nervous System Diseases; Tetrahydrofolates

Cerebral folate deficiency (CFD) is defined as any neurological syndrome associated with a low cerebrospinal fluid (CSF) concentration of 5-methyltetrahydrofolate (5MTHF) in the presence of normal peripheral folate status. CFD has a wide clinical presentation, with reported signs and symptoms generally beginning at around 4 months of age with irritability and sleep disturbances. These can be followed by psychomotor retardation, dyskinesia, cerebellar ataxia and spastic diplegia. Other signs may include deceleration of head growth, visual disturbances and sensorineural hearing loss. Identification of CFD is achieved by determining 5MTHF concentration in CSF. Once identified, CFD can in many cases be treated by administering oral folinic acid. Supplementation with folic acid is contraindicated and, if used, may exacerbate the CSF 5MTHF deficiency. Generation of autoantibodies against the folate receptor required to transport 5MTHF into CSF and mutations in the folate receptor 1 (FOLR1) gene have been reported to be causes of CFD. However, other mechanisms are probably also involved, as CFD has been reported in Aicardi-Goutiere's and Rett syndromes and in mitochondriopathies. Several metabolic conditions and a number of widely used drugs can also lead to a decrease in the concentration of CSF 5MTHF, and these should be considered in the differential diagnosis if a low concentration of 5MTHF is found following CSF analysis.

Topics: Administration, Oral; Autoantibodies; Brain Diseases; Dietary Supplements; Folate Receptor 1; Folic Acid Deficiency; Folic Acid Transporters; Genetic Predisposition to Disease; Humans; Leucovorin; Mutation; Risk Factors; Tetrahydrofolates; Treatment Outcome

Cerebral folate deficiency (CFD) is associated with low levels of 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) with normal folate levels in the plasma and red blood cells. The onset of symptoms caused by the deficiency of folates in the brain is at around 4 to 6 months of age. This is followed by delayed development, with deceleration of head growth, hypotonia, and ataxia, followed in one-third of children by dyskinesias (choreo-athetosis, hemiballismus), spasticity, speech difficulties, and epilepsy. The low level of 5-methyltetrahydrofolate in the CSF can result from decreased transport across the blood-brain barrier, which is most probably because of the blocking of folate transport into the CSF by the binding of folate receptor antibodies to the folate receptors in the choroid plexus. Treatment of the condition with folinic acid for prolonged periods can result in significant improvement of clinical symptoms and a return of 5-methyltetrahydrofolate levels in the CSF to normal. In view of this response to treatment in CFD and allied conditions, a case can be made for screening the CSF of patients with neurological disorders of unknown origin.

Topics: Blood-Brain Barrier; Brain Diseases; Cerebral Cortex; Child; Folic Acid Deficiency; Humans; Infant; Tetrahydrofolates

Supplementation with folate may help reduce depressive symptoms. Folate, a naturally occurring B vitamin, is needed in the brain for the synthesis of norepinephrine, serotonin, and dopamine. Three forms of folate are commonly used: folic acid, 5-methyltetrahydrofolate (5-MTHF) (also known as methylfolate and L-methylfolate), and folinic acid. Some forms may be more bioavailable than others in patients with a genetic polymorphism and in those who take particular medications or use alcohol. Folic acid augmentation in depressed patients may reduce residual symptoms. The 5-MTHF formulation indicated efficacy as adjunctive therapy or monotherapy in reducing depressive symptoms in patients with normal and low folate levels, improving cognitive function and reducing depressive symptoms in elderly patients with dementia and folate deficiency, and reducing depressive and somatic symptoms in patients with depression and alcoholism. Adjunctive folinic acid reduced depressive symptoms in patients who were partially responsive or nonresponsive to a selective serotonin reuptake inhibitor. Evidence for the efficacy of folate in improving cognitive symptoms is equivocal, but most studies used folic acid. Although the studies reviewed have limitations and, historically, concerns have been raised about the role of folate in increasing cancer risk, masking B(12) deficiency, and worsening depressive symptoms, folate is generally well tolerated, and 5-MTHF may be less likely to incur some of these risks. Several forms of folate appear to be safe and efficacious in some individuals with major depressive disorder, but more information is needed about dosage and populations most suited to folate therapy.

Topics: Aged; Chemistry, Pharmaceutical; Clinical Trials as Topic; Dementia; Depressive Disorder, Major; Dietary Supplements; Dosage Forms; Female; Folic Acid; Folic Acid Deficiency; Humans; Leucovorin; Male; Tetrahydrofolates; Treatment Outcome

Depression is common - one-fourth of the U.S. population will have a depressive episode sometime in life. Folate deficiency is also relatively common in depressed people, with approximately one-third of depressed individuals having an outright deficiency. Folate is a water-soluble B-vitamin necessary for the proper biosynthesis of the monoamine neurotransmitters serotonin, epinephrine, and dopamine. The active metabolite of folate, 5-methyltetrahydrofolate (5-MTHF, L-methylfolate), participates in re-methylation of the amino acid metabolite homocysteine, creating methionine. S-adenosylmethionine (SAMe), the downstream metabolite of methionine, is involved in numerous biochemical methyl donation reactions, including reactions forming monoamine neurotransmitters. Without the participation of 5-MTHF in this process, SAMe and neurotransmitter levels decrease in the cerebrospinal fluid, contributing to the disease process of depression. SAMe supplementation was shown to improve depressive symptoms. 5-MTHF also appears to stabilize, enhance production of, or possibly act as a substitute for, tetrahydrobiopterin (BH4), an essential cofactor in monoamine neurotransmitter biosynthesis. There are few intervention studies of folic acid or 5-MTHF as a stand-alone treatment for depression related to folate deficiency; however, the studies that have been conducted are promising. Depressed individuals with low serum folate also tend to not respond well to selective serotonin reuptake inhibitor (SSRI) antidepressant drugs. Correcting the insufficiency by dosing folate along with the SSRI results in a significantly better antidepressant response.

Topics: Antioxidants; Biopterins; Depression; Folic Acid Deficiency; Homocysteine; Humans; Methionine; Methylation; Neurotransmitter Agents; S-Adenosylmethionine; Selective Serotonin Reuptake Inhibitors; Tetrahydrofolates

Cobalamin deficiency leads to impaired folate function as demonstrated by markedly impaired single-carbon unit transfer into purine, thymidine and methionine. This occurs in the total absence of 'methylH4folate trapping'. In cobalamin deficiency there is impaired synthesis of formylH4folate and raised levels of endogenous formate in blood and liver. FormylH4folate and methionine reverse the effects of cobalamin deficiency. Methionine provides formate via its metabolism to methylthioribose. Recently it has been suggested that the neuropathy of cobalamin deficiency is due to impaired methylation but this was not confirmed. It is likely that defects demonstrated in marrow and liver are also the explanation for the effects of cobalamin deficiency in the CNS.

Topics: Anemia, Megaloblastic; Animals; Central Nervous System Diseases; Coenzymes; Folic Acid; Folic Acid Deficiency; Formates; Humans; Methionine; Models, Biological; Tetrahydrofolates; Thymidine; Vitamin B 12; Vitamin B 12 Deficiency

Topics: 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; Anemia, Megaloblastic; Animals; Central Nervous System; Deoxyuridine; Disease Models, Animal; Drug Interactions; Enzyme Activation; Folic Acid; Folic Acid Deficiency; Histidine; Humans; Liver; Methionine; Methylmalonyl-CoA Mutase; Nitrous Oxide; Oxidation-Reduction; Pteroylpolyglutamic Acids; Purines; Serine; Tetrahydrofolates; Thymidylate Synthase; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Alcoholism; Anemia, Hemolytic; Anticonvulsants; Bone Marrow Cells; Bone Marrow Diseases; Cells; Deoxyuridine; Erythrocytes, Abnormal; Female; Fluorouracil; Folic Acid; Folic Acid Deficiency; Formyltetrahydrofolates; Homocysteine; Humans; Hypothyroidism; Lymphocyte Activation; Methionine; Pregnancy; Pregnancy Complications; Statistics as Topic; Tetrahydrofolates; Vitamin B 12; Vitamin B 12 Deficiency

Studies in nonpregnant, nonlactating women suggest that folate supplementation in the form of 5-methyltetrahydrofolate ([6S]-5-methylTHF) is at least as effective as folic acid in increasing blood folate indexes. No data, however, are available on the effect of supplemental [6S]-5-methylTHF on blood folate concentrations during lactation.. We assessed the relative effectiveness of [6S]-5-methylTHF, a placebo, and folic acid in maintaining blood folate indexes during lactation in a sample of healthy Canadian women consuming folic acid-fortified foods.. This study was designed as a 16-wk, randomized, placebo-controlled intervention. Pregnant women (n = 72) advised to consume a folic acid-containing prenatal supplement (1000 microg/d) during pregnancy were enrolled at 36 wk gestation. After delivery, the women were randomly assigned to receive [6S]-5-methylTHF (416 microg/d, 906 nmol/d) or a placebo or were assigned to a folic acid (400 microg/d, 906 nmol/d) reference group.. At 16 wk of lactation, the mean red blood cell (RBC) folate concentration in women in the [6S]-5-methylTHF group (2178; 95% CI: 1854, 2559 nmol/L) was greater than that in the folic acid (1967; 1628, 2377 nmol/L; P < 0.05) and placebo (1390; 1198, 1613 nmol/L; P < 0.002) groups after adjustment for baseline concentrations (36 wk gestation). The distribution of folate forms in RBCs did not differ significantly between the [6S]-5-methylTHF and placebo groups. However, the folic acid group had greater amounts of 5-formylTHF (P < 0.03).. [6S]-5-MethylTHF appeared to be as effective as, and perhaps more effective than, folic acid in preserving RBC folate concentrations during lactation.

Topics: Adult; Biological Availability; Blood Chemical Analysis; Dietary Supplements; Double-Blind Method; Erythrocytes; Female; Folic Acid; Folic Acid Deficiency; Humans; Lactation; Placebos; Pregnancy; Tetrahydrofolates; Treatment Outcome; Vitamin B Complex

Topics: Cells, Cultured; Cerebrum; Down-Regulation; Female; Folate Receptor 1; Folic Acid Deficiency; HEK293 Cells; Humans; Loss of Function Mutation; Male; Nervous System Diseases; Neuroaxonal Dystrophies; Pedigree; Repressor Proteins; Sequence Analysis, DNA; Tetrahydrofolates

Topics: Cadherins; Child; Epileptic Syndromes; Female; Folic Acid Deficiency; Humans; Leucovorin; Pedigree; Protocadherins; Tetrahydrofolates; Treatment Outcome; Vitamin B Complex

We aim to examine the relation of several folate forms (5-methyltetrahydrofolate [5-mTHF], unmetabolized folic acid [UMFA], non-methyl folate, and MeFox [pyrazino-s-triazine derivative of 4α-hydroxy-5-methyltetrahydrofolate]) with the risk of mortality.. Using data from National Health and Nutrition Examination Survey 2011-2014, a total of 10,661 people with folate forms data were recruited. Death information was obtained from the National Death Index until 2015. Cox proportional hazards regression models were developed to evaluate the relationship between folate forms and mortality.. During 2.99 years of follow-up, 344 (2.6%) deaths occurred. Overall, significantly higher risks of all-cause mortality were found in participants with higher level of serum 5-mTHF (≥51.3 nmol/L [quartile 4] vs. 23.9-51.3 nmol/L [quartile 2-3]; HR, 1.61; 95% CI: 1.03-2.53), UMFA (≥1.1 nmol/L [quartile 4] vs. <1.1 nmol/L [quartile 1-3]; HR, 1.55; 95% CI: 1.15-2.09), non-methyl folate (≥1.7 nmol/L [quartile 4] vs. 1.2-1.7 nmol/L [quartile 3]; HR, 1.62; 95% CI: 1.06-2.48), or MeFox (≥2.5 nmol/L [quartile 4] vs. <2.5 nmol/L [quartile 1-3]; HR, 1.54; 95% CI: 1.11-2.12). In addition, there was an increased risk of all-cause mortality for those with low level of serum 5-mTHF (<23.9 nmol/L [quartile 1] vs. 23.9-51.3 nmol/L [quartile 2-3]; HR, 1.66; 95% CI: 1.12-2.47). Most importantly, none of any folate forms significantly modified the association between other folate forms and mortality (all P for interactions >0.05).. Higher levels of serum folate forms (5-mTHF, UMFA, non-methyl folate, and MeFox) were associated with higher risk of mortality while 5-mTHF insufficiency also showed a negative impact on mortality. Our findings emphasized the importance of monitoring the folate forms concentrations and may help counsel future related clinical trials.

Topics: Adult; Female; Folic Acid; Folic Acid Deficiency; Humans; Male; Middle Aged; Nutrition Surveys; Proportional Hazards Models; Prospective Studies; Risk Factors; Tetrahydrofolates

Topics: Anemia, Pernicious; Female; Folic Acid Deficiency; Gastritis, Atrophic; Homocysteine; Humans; Hydroxocobalamin; Methylmalonic Acid; Middle Aged; Tetrahydrofolates; Vitamin B 12; Vitamin B Complex

Cerebral folate deficiency (CFD) is a neurological disease, hallmarked by remarkable low concentrations of 5-methyltetrahydrofolic acid (5-MTHF) in cerebrospinal fluid (CSF). The primary causes of CFD include the presence of folate receptor (FR) autoantibodies, defects of FR encoding gene FOLR1, mitochondrial diseases and congenital abnormalities in folate metabolism.. Here we first present a Chinese male CFD patient whose seizure onset at 2 years old with convulsive status epilepticus. Magnetic Resonance Imaging (MRI) revealed the development of encephalomalacia, laminar necrosis in multiple lobes of the brain and cerebellar atrophy. Whole Exome Sequencing (WES) uncovered a homozygous missense variant of c.524G > T (p.C175F) in FOLR1 gene. Further laboratory tests demonstrated the extremely low level of 5-MTHF in the CSF from this patient, which was attributed to cerebral folate transport deficiency. Following the intravenous and oral treatment of calcium folinate, the concentrations of 5-MTHF in CSF were recovered to the normal range and seizure symptoms were relieved as well.. One novel variation of FOLR1 was firstly identified from a Chinese male patient with tonic-clonic seizures, developmental delay, and ataxia. The WES and laboratory results elucidated the etiology of the symptoms. Clinical outcomes were improved by early diagnosis and proper treatment.

Topics: Age of Onset; Cerebral Cortex; Child; Encephalomalacia; Exome Sequencing; Folate Receptor 1; Folic Acid Deficiency; Homozygote; Humans; Leucovorin; Magnetic Resonance Imaging; Male; Seizures; Status Epilepticus; Tetrahydrofolates

To describe the phenotype and the response to folinic acid supplementation of cerebral folate deficiency (CFD) in adults, a disorder diagnosed on low 5-methyltetrahydro-folate (5MTHF) in cerebrospinal fluid (CSF), which can correspond to a inherited disorder of folate metabolism (IDFM) or to a metabolic consequence of various neurological diseases.. We conducted a retrospective study on 224 adult patients with neurological symptoms who had a 5MTHF CSF dosage, collecting their neurologic and neuroimaging data.. 69 patients had CFD (CSF 5MTHF level < 41 nmol/L), 25 of them had severe CFD (sCFD; ≤25 nmol/L) with adult onset neurological symptoms in 41%. 56% of sCFD patients had an underlying identified neurologic disorder, mainly mitochondrial diseases, hepatic encephalopathy and primary brain calcifications (no identified IDFM), the others were classified as undiagnosed. sCFD patients presented most frequently pyramidal syndrome (75%), movement disorders (56%), cerebellar syndrome (50%) and intellectual disability (46%). MRI findings mostly showed white matter abnormalities (WMA; 32%) and calcifications (12%), and were normal in 23%. The clinico-radiological phenotype of sCFD patients was not clearly different from non CFD patients in terms of manifestations frequency. However, their neurological picture was more complex with a higher number of combined neurological symptoms (4.7±1.6 vs 3.4±1.7, p = .01). In Magnetic Resonance Spectroscopy (MRS), Choline/Creatine (Cho/Cr) ratio was lower in sCFD patients (n = 7) compared to non-CFD patients (n = 73) (p = .005), with good sensitivity (71%) and excellent specificity (92%). Among twenty-one CFD patients treated with folinic acid, nine had a sustained improvement, all with sCFD but one (50% of sCFD patients improved). In two undiagnosed patients with extremely low 5MTHF CSF values, MRI WMA and low Cho/Cr ratios, folinic acid treatment leaded to a dramatic clinical and radiological improvement.. CSF 5MTHF dosage should be considered in patients with mitochondrial diseases, primary brain calcifications and unexplained complex neurological disorders especially if associated with WMA, since folinic acid supplementation in patients with sCFD is frequently efficient.

Topics: Adolescent; Adult; Aged; Calcinosis; Cerebellar Diseases; Child; Child, Preschool; Female; Folic Acid; Folic Acid Deficiency; Follow-Up Studies; Humans; Infant; Infant, Newborn; Intellectual Disability; Magnetic Resonance Imaging; Male; Middle Aged; Mitochondrial Diseases; Mutation; Proteins; Retrospective Studies; Tetrahydrofolates; White Matter; Young Adult

BACKGROUND Maternal folate deficiency-mediated metabolic disruption is considered to be associated with the risk of intrauterine growth retardation (IUGR), but the exact mechanism remains unclear. The retrotransposon long interspersed nucleotide element-1 (LINE-1), which can induce birth defects via RNA intermediates, plays crucial roles during embryonic development. We investigated potential relationships between maternal folate and DNA methylation, and possible roles of LINE-1 in IUGR. MATERIAL AND METHODS The IUGR model was established by feeding female mice 1 of 3 diets - control diet (CD), folate-deficient diet for 2 weeks (FD2w), and folate-deficient diet for 4 weeks (FD4w) - prior to mating. Maternal serum folate, 5-methyltetrahydrofolate (5-MeTHF), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) concentrations and global DNA methylation were assessed by LC/MS/MS method. LINE-1 methylation levels in fetuses were examined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. LINE-1 expression levels were validated by real-time PCR. RESULTS Maternal folate deficiency caused plasma folate and 5-MeTHF levels to decrease and SAH level to increase in the FD4w group. Compared with the CD group, methylation levels of genomic DNA and LINE-1 decreased significantly in placenta and fetal tissues from the FD4w group. Expression of LINE-1 open reading frame 1 (ORF1) protein was elevated in fetal liver tissues. Furthermore, a strong correlation was found between methylation and disrupted one-carbon metabolism, implying that dietary folate plays important roles during embryogenesis. CONCLUSIONS Maternal dietary folate deficiency impaired one-carbon metabolism, leading to global DNA and LINE-1 hypomethylation, and then increased retrotransposition in fetuses, which can lead to IUGR.

Topics: Animals; Disease Models, Animal; DNA Methylation; Female; Fetal Growth Retardation; Fetus; Folic Acid; Folic Acid Deficiency; Long Interspersed Nucleotide Elements; Male; Maternal-Fetal Exchange; Mice; Mice, Inbred C57BL; Placenta; Pregnancy; S-Adenosylhomocysteine; S-Adenosylmethionine; Tetrahydrofolates

Topics: Amino Acid Substitution; Cell Line; Folic Acid Deficiency; HeLa Cells; Humans; Infant; Malabsorption Syndromes; Male; Models, Molecular; Mutagenesis, Site-Directed; Mutation, Missense; Protein Transport; Proton-Coupled Folate Transporter; Substrate Specificity; Tetrahydrofolates; Transfection

Despite efforts to increase folic acid (FA) intake, even within countries mandating FA fortification, there remain pregnant women with folate levels inadequate to minimize congenital disorders (e.g., of the neural tube, heart, and lip/palate). The pharmacokinetics of FA and [6S]-5-methyltetrahydrofolate (5-MTHF) were examined to find a reliable and minimal dose for rapidly rescuing folate status prior to critical periods of embryonic development. Serum total folate increased much more rapidly over the first four days in insufficient women given 7.5 mg doses of 5-MTHF than the same regimen of FA (P for trend <0.0001). Nearly all women given 7.5 mg 5-MTHF (every 12 hours, five doses total) almost immediately reached 50 nM serum total folate. Moreover, this level could be maintained by subsequent administration of 0.4 mg/d of folic acid. Thus, 5-MTHF enables repletion of folate stores more quickly and uniformly than FA and without exposure to unmetabolized FA.

Topics: Adult; Congenital Abnormalities; Female; Folic Acid; Folic Acid Deficiency; Humans; Plasma; Pregnancy; Pregnancy Complications; Tetrahydrofolates; Treatment Outcome; Young Adult

Epigenetics (particularly DNA methylation) together with environmental and genetic factors, are key to understanding the pathogenesis of many diseases including dementia. Disturbances in DNA methylation have already been implicated in dementia. Homocysteine metabolism, with folate and vitamin B12 as essential cofactors, is integral to methylation processes. We evaluated in a case-control study the association of global DNA methylation, homocysteine, folate and vitamin B12 status with dementia. Selected polymorphisms of genes previously associated with dementia development and the influence of various factors on DNA methylation were also investigated. 102 patients with dementia (53 with Alzheimer's disease, 17 with vascular dementia and 32 with mixed dementia) were recruited. The non-demented controls consisted of 45 age-matched subjects without dementia and 47 individuals with mild cognitive impairment. Global DNA methylation was determined by Imprint Methylated DNA Quantification Kit MDQ1 (Sigma-Aldrich, Gillingham, Dorset, UK). Plasma homocysteine, serum folate and vitamin B12 were determined by chemiluminescence. Plasma and erythrocyte 5-methyltetrahydrofolate and plasma methylmalonic acid (markers of folate and vitamin B12 status) were measured by HPLC. APOE, PON1 p.Q192R, MTHFR 677C>T (c.665C>T) and IL1B-511C>T polymorphisms were identified using PCR-RFLP methods. Patients with dementia had significantly higher concentrations of homocysteine (p=0.012) and methylmalonic acid (p=0.016) and lower folate (p=0.002) and plasma 5-methyltetrahydrofolate (p=0.005) than non-demented subjects. There was no difference in DNA methylation between patients and controls. A non-significant tendency to higher DNA methylation in patients with vascular dementia (p=0.061) was observed. Multivariate regression analysis of all recruited individuals demonstrated a significant positive association between DNA methylation and folate (p=0.013), creatinine (p=0.003) concentrations and IL1B-511T (p=0.002) and PON1 192R (p=0.049) alleles and negative association with fasting glucose (p=0.004). The biochemical results showed significantly lower folate and vitamin B12 status in demented patients than controls. Global DNA methylation was associated with markers of folate status, creatinine, glucose and PON1 and IL1B polymorphisms.

Topics: Aged; Aryldialkylphosphatase; Case-Control Studies; Dementia; DNA Methylation; Female; Folic Acid; Folic Acid Deficiency; Homocysteine; Humans; Interleukin-1beta; Male; Middle Aged; Poland; Polymorphism, Restriction Fragment Length; Tetrahydrofolates; Vitamin B 12

Topics: Dermis; Epidermis; Folic Acid Deficiency; Humans; Pilot Projects; Skin; Tetrahydrofolates; Ultraviolet Rays

Cerebral folate deficiency (CFD) may be underdiagnosed, as it manifests with various non-specific neurological symptoms. The diagnosis of CFD requires a determination of 5-methyltetrahydrofolate (5MTHF) in the cerebrospinal fluid (CSF), which is available in a limited number of specialized laboratories. In clinical biochemistry laboratories, total folate (TF) determination in serum or plasma is routinely performed by automated analyzers. The aim of this study is to determine whether the automated assay of CSF TF is a helpful screening tool for CFD.. We analyzed CSF samples collected from 73 pediatric patients. We measured CSF TF, serum TF, and CSF 5MTHF in 73, 70, and 48 patients, respectively. The assay of 5MTHF was conducted by a newly developed system utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS). We investigated the correlation between TF and 5MTHF in the CSF.. There was a strong positive correlation between CSF TF and 5MTHF (ρ=0.930, p<0.0001, n=48). Age was negatively correlated with CSF TF (ρ=-0.557, p<0.0001, n=51), serum TF (ρ=-0.457, p=0.0008, n=51), and CSF 5MTHF (ρ=-0.387, p=0.0263, n=33), but not with the CSF/serum TF ratio.. The automated assay of CSF TF is helpful to estimate CSF 5MTHF. The CSF TF assay may have a significant impact on the early diagnosis of CFD, because clinicians have better access to it than the 5MTHF assay.

Topics: Adolescent; Cerebellar Diseases; Child; Child, Preschool; Chromatography, High Pressure Liquid; Early Diagnosis; Folic Acid; Folic Acid Deficiency; Humans; Infant; Reference Values; Tandem Mass Spectrometry; Tetrahydrofolates

Folinic acid-responsive seizures (FARS) are a rare treatable cause of neonatal epilepsy. They have characteristic peaks on CSF monoamine metabolite analysis, and have mutations in the ALDH7A1 gene, characteristically found in pyridoxine-dependent epilepsy. There are case reports of patients presenting with seizures at a later age, and with folate deficiency due to different mechanisms with variable response to folinic acid supplementation. Here, we report 2 siblings who presented with global developmental delay and intractable seizures who responded clinically to folinic acid therapy. Their work-up included metabolic and genetic testing. The DNA sequencing was carried out for the ALDH7A1 gene, and the folate receptor 1 (FOLR1) gene. They had very low 5-methyltetrahydrofolate (5-MTHF) in CSF with no systemic folate deficiency and no characteristic peaks on neurotransmitter metabolite chromatogram. A novel mutation in the FOLR1 gene was found. The mutation in this gene is shown to affect CSF folate transport leading to cerebral folate deficiency. The response to treatment with folinic acid was dramatic with improvement in social interaction, mobility, and complete seizure control. We should consider the possibility of this treatable condition in appropriate clinical circumstances early, as diagnosis with favorable outcome depends on the specialized tests.

Topics: Atrophy; Brain; Brain Diseases, Metabolic, Inborn; Child Development Disorders, Pervasive; Child, Preschool; Consanguinity; Developmental Disabilities; Early Diagnosis; Electroencephalography; Epilepsies, Myoclonic; Female; Folate Receptor 1; Folic Acid Deficiency; Humans; Leucovorin; Magnetic Resonance Imaging; Male; Mutation, Missense; Point Mutation; Pyridoxine; Siblings; Tetrahydrofolates

A low folate or low thiamine status may be associated with the risk of preterm delivery, small for gestational age (SGA) offspring and adverse pregnancy outcomes.. 5-Methyltetrahydrofolate (5MTHF) and thiamine diphosphate (TDP) were measured directly in cord-blood erythrocytes (CBEs) of early preterm (n=26; <32 weeks gestational age; including 50% multiple births), late preterm (n=38; 32 to <37 weeks; including 24% multiple births) and term newborns (n=60, 37-42 weeks) via high-performance liquid chromatography and fluorescence detection. Associations between 5MTHF and TDP with gestational age, newborn anthropometrics (birth weight, newborn's length and head circumference) and risk of being SGA were explored.. Group comparison as well as multivariate linear regression analysis of cord-blood vitamins revealed that 5MTHF was significantly lower in late preterms compared with terms but did not differ between singletons and multiples. TDP tended to be higher in preterms than in terms and lower in multiples than in singletons in both early and late preterms. Multivariate analysis on birth outcomes showed that 5MTHF was significantly positively associated with gestational age, birth weight and newborn's length. 5MTHF, increasing gestational age and parity were associated with a significantly reduced risk for being SGA, while TDP, multiple births and gender were not associated with the risk for being SGA.. Higher CBE concentrations of 5MTHF were associated with improved birth outcomes. Lower TDP concentrations were observed in multiple births. Future studies evaluating cord-blood vitamin concentrations and their associations with birth outcomes should additionally include dietary intakes and maternal blood concentrations at different stages of pregnancy.

Topics: Adult; Birth Weight; Body Height; Female; Fetal Blood; Folic Acid Deficiency; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Infant, Small for Gestational Age; Linear Models; Male; Mothers; Multiple Birth Offspring; Parity; Pregnancy; Pregnancy Outcome; Premature Birth; Tetrahydrofolates; Thiamine Pyrophosphate; Vitamin B Deficiency

Folates, an essential component (important B vitamin) in the human diet, are involved in many metabolic pathways, mainly in carbon transfer reactions such as purine and pyrimidine biosynthesis and amino acid interconversions. Deficiency of this micronutrient leads to the disruption of folate-dependent metabolic pathways that lead to the development of clinical abnormalities ranging from anaemia to growth retardation. Folate deficiency due to alcohol ingestion is quite common, primarily due to malabsorption. The present study dealt with the mechanistic insights of folate malabsorption in colonic basolateral membrane (BLM). Wistar rats (n 12) were fed 1 g/kg body weight per d ethanol (20 %) solution orally for 3 months and folate transport was studied in the isolated colonic BLM. The folate exit across colon BLM shows characteristics of carrier-mediated process with the major involvement of reduced folate carrier (RFC). The chronic ethanol ingestion decreased the uptake by decreasing the affinity by 46 % (P < 0·01) and the number of transport molecules by 43 % (P < 0·001) at the colon BLM. The decreased uptake was associated with down-regulation of proton-coupled folate transporter (PCFT) and RFC expression at mRNA and protein levels. The extent of decrease was 44 % (P < 0·01) and 24 % (P < 0·05) for PCFT and 23 % (P < 0·01) and 57 % (P < 0·01) for RFC at mRNA and protein levels, respectively. Moreover, folate transporters were associated with lipid rafts (LR) of colon BLM, and chronic alcoholism decreased the association of these transporters with LR.

Topics: Alcoholism; Animals; Cell Membrane; Colon; Down-Regulation; Folic Acid; Folic Acid Deficiency; Intestinal Absorption; Intestinal Mucosa; Kinetics; Malabsorption Syndromes; Male; Membrane Microdomains; Membrane Transport Proteins; Minor Histocompatibility Antigens; Proton-Coupled Folate Transporter; Random Allocation; Rats; Rats, Wistar; Reduced Folate Carrier Protein; RNA, Messenger; Tetrahydrofolates

Peri-conceptional use of folic acid contributes to protection against congenital malformations, such as neural tube defects and cleft lip with or without cleft palate (CL/P). Previous studies showed that low folate levels cause DNA damage, leading to chromosomal instability and aneusomy. This study seeks to confirm this finding and investigates whether the in vitro sensitivity towards aneusomy of chromosome 17 and 21 in the folate-deficient state differs between CL/P patients and controls.. Epstein-Barr virus-immortalized B-lymphoblasts derived from 15 CL/P children and 15 controls, were cultured in medium with high and low concentrations - approximately 40nM and 5nM - of 5-methyltetrahydrofolate, respectively. Fluorescence in situ hybridization was used to detect specific fluorescence signals for chromosomes 17 and 21.. A significant increase in aneusomy of chromosomes 17 (2.3% vs 7.6%; p ≤ 0.001) and 21 (2.5% vs 7.0%; p ≤ 0.001) was observed after 10 days of culturing in low folate. These results were comparable in cell lines from patients and controls. Interestingly, for chromosome 17 the folate deficiency mainly resulted in an increase of monosomy (6%, p ≤ 0.001), while for chromosome 21 the increase of trisomy was larger (4.9%, p ≤ 0.001).. These data suggest that folate deficiency is a significant risk factor in the development of aneusomy and may affect the distribution of chromosomes during cell division. The comparable aneusomy frequencies in CL/P and in controls suggest that other folate-related processes are involved in the pathogenesis of CL/P, and additional investigations are needed to identify the causal mechanisms.

Topics: Aneuploidy; B-Lymphocytes; Cell Line; Cells, Cultured; Child, Preschool; Chromosomal Instability; Chromosomes, Human, Pair 17; Chromosomes, Human, Pair 21; Cleft Lip; Cleft Palate; Female; Folic Acid Deficiency; Humans; Male; Tetrahydrofolates

Cerebral folate transport deficiency is an inherited brain-specific folate transport defect that is caused by mutations in the folate receptor 1 gene coding for folate receptor alpha (FRα). This genetic defect gives rise to a progressive neurological disorder with late infantile onset. We screened 72 children with low 5-methyltetrahydrofolate concentrations in the cerebrospinal fluid and neurological symptoms that developed after infancy. We identified nucleotide alterations in the folate receptor 1 gene in 10 individuals who shared developmental regression, ataxia, profound cerebral hypomyelination and cerebellar atrophy. We found four novel pathogenic alleles, one splice mutation and three missense mutations. Heterologous expression of the missense mutations, including previously described mutants, revealed minor decrease in protein expression but loss of cell surface localization, mistargeting to intracellular compartments and thus absence of cellular binding of folic acid. These results explain the functional loss of folate receptor alpha for all detected folate receptor 1 mutations. Three individuals presenting a milder clinical phenotype revealed very similar biochemical and brain imaging data but partially shared pathogenic alleles with more severely affected patients. Thus, our studies suggest that different clinical severities do not necessarily correlate with residual function of folate receptor alpha mutants and indicate that additional factors contribute to the clinical phenotype in cerebral folate transport deficiency.

Topics: Adolescent; Alleles; Animals; Child; Child, Preschool; CHO Cells; Cricetinae; Female; Fibroblasts; Folate Receptor 1; Folic Acid; Folic Acid Deficiency; Hep G2 Cells; Humans; Magnetic Resonance Imaging; Male; Mutation; Phenotype; Protein Transport; Tetrahydrofolates

Topics: Biomarkers; Biopterins; Brain Diseases, Metabolic; Child; Folic Acid Deficiency; Humans; Male; Self-Injurious Behavior; Tetrahydrofolates

Topics: Combined Modality Therapy; Depressive Disorder; Dietary Supplements; Folic Acid Deficiency; Humans; Tetrahydrofolates; United States; United States Food and Drug Administration

Cerebral folate deficiency may be amenable to therapeutic supplementation. Diverse metabolic pathways and unrelated processes can lead to cerebrospinal fluid 5-methyltetrahydrofolate (5-MTHF) depletion, the hallmark of cerebral folate deficiency.. To analyze cerebral folate abundance in a large prospective series of children diagnosed with any neurologic disorder for which a diagnostic lumbar puncture was indicated.. We studied the spectrum and frequency of disorders associated with cerebral folate deficiency by measuring cerebrospinal fluid 5-MTHF, biogenic amines, and pterins. Direct sequencing of the FOLR1 transporter gene was also performed in some patients.. Academic pediatric medical center.. We studied 134 individuals free of neurometabolic disease and 584 patients with any of several diseases of the central nervous system.. Of 584 patients, 71 (12%) exhibited 5-MTHF deficiency. Mild to moderate deficiency (n = 63; range, 19-63 nmol/L) was associated with perinatal asphyxia, central nervous system infection, or diseases of probable genetic origin (inborn errors of metabolism, white matter disorders, Rett syndrome, or epileptic encephalopathies). Severe 5-MTHF depletion (n = 8; range, 0.6-13 nmol/L) was detected in severe MTHF reductase deficiency, Kearns-Sayre syndrome, biotin-responsive striatal necrosis, acute necrotizing encephalitis of Hurst, and FOLR1 defect. A strong correlation was observed between cerebrospinal fluid and plasma folate levels in cerebral folate deficiency.. Of the 2 main forms of cerebral folate deficiency identified, mild to moderate 5-MTHF deficiency was most commonly associated with disorders bearing no primary relation to folate metabolism, whereas profound 5-MTHF depletion was associated with specific mitochondrial disorders, metabolic and transporter defects, or cerebral degenerations. The results suggest that 5-MTHF can serve either as the hallmark of inborn disorders of folate transport and metabolism or, more frequently, as an indicator of neurologic dysfunction.

Topics: Adolescent; Biogenic Amines; Brain; Child; Child, Preschool; Female; Folate Receptor 1; Folic Acid; Folic Acid Deficiency; Humans; Infant; Infant, Newborn; Male; Prospective Studies; Pterins; Sequence Analysis, DNA; Spinal Puncture; Tetrahydrofolates

Dynamical modeling is an accurate tool for describing the dynamic regulation of one-carbon metabolism (1CM) with emphasis on the alteration of DNA methylation and/or dUMP methylation into dTMP. Using logic programming we present a comprehensive and adaptative mathematical model to study the impact of folate deficiency, including folate transport and enzymes activities. 5-Methyltetrahydrofolate (5mTHF) uptake and DNA and dUMP methylation were studied by simulating nutritional 5mTHF deficiency and methylenetetrahydrofolate reductase (MTHFR) gene defects. Both conditions had distinct effects on 1CM metabolite synthesis. Simulating severe 5mTHF deficiency (25% of normal levels) modulated 11 metabolites. However, simulating a severe decrease in MTHFR activity (25% of normal activity) modulated another set of metabolites. Two oscillations of varying amplitude were observed at the steady state for DNA methylation with severe 5mTHF deficiency, and the dUMP/dTMP ratio reached a steady state after 2 h, compared to 2.5 h for 100% 5mTHF. MTHFR activity with 25% of V(max) resulted in an increased methylated DNA pool after half an hour. We observed a deviation earlier in the profile compared to 50% and 100% V(max). For dUMP methylation, the highest level was observed with 25%, suggesting a low rate of dUMP methylation into dTMP with 25% of MTHFR activity. In conclusion, using logic programming we were able to construct the 1CM for analyzing the dynamic system behavior. This model may be used to refine biological interpretations of data or as a tool that can provide new hypotheses for pathogenesis.

Topics: Artificial Intelligence; DNA Methylation; Folic Acid Deficiency; Humans; Logic; Metabolic Networks and Pathways; Methylenetetrahydrofolate Reductase (NADPH2); Models, Biological; One-Carbon Group Transferases; Systems Biology; Tetrahydrofolates

Cerebral folate deficiency (CFD) is increasingly recognized in various neurological conditions, raising the question of whether it might represent a clear-cut clinical syndrome.. Retrospective analysis of patients with low cerebral spinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) values was performed.. 58 pediatric patients with low (-2nd to -3rd standard deviation) and 45 patients with very low 5MTHF values (<3rd standard deviation) were identified, including 22 patients with defined underlying neurological conditions. The leading symptoms were mental retardation (n=84), motor retardation (n=75), epilepsy (n=53), ataxia (n=44) and pyramidal tract signs (n=37). There was no relationship between 5MTHF levels and the severity of clinical disease, the duration of clinical disease, distinct neurological symptoms and antiepileptic drug treatment, respectively. Genetical analysis for mutations in the folate receptor 1 gene proved normal in all 16 children studied.. For the majority of patients CFD is not a clear-cut neurometabolic syndrome but the common result of different genetic, metabolic or unknown processes. Nevertheless, CFD may represent a treatable disease-modifying factor which should therefore be addressed in prospective studies.

Topics: Abnormalities, Multiple; Adolescent; Ataxia; Child; Child, Preschool; Epilepsy; Female; Folic Acid Deficiency; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Pyramidal Tracts; Retrospective Studies; Syndrome; Tetrahydrofolates; Young Adult

Folate nutrition is critical in humans and a high dietary folate intake is associated with a diminished risk of many types of cancer. Both synthetic folic acid and the most biologically abundant extracellular reduced folate, 5-methyltetrahydrofolate, are degraded under conditions of ultraviolet radiation (UVR) exposure. Skin is a proliferative tissue with increased folate nutrient demands due to a dependence upon continuous epidermal cell proliferation and differentiation to maintain homeostasis. Regions of skin are also chronically exposed to UVR, which penetrates to the actively dividing basal layer of the epidermis, increasing the folate nutrient demands in order to replace folate species degraded by UVR exposure and to supply the folate cofactors required for repair of photo-damaged DNA. Localized folate deficiencies of skin are a likely consequence of UVR exposure. We report here a cultured keratinocyte model of folate deficiency that has been applied to examine possible effects of folate nutritional deficiencies in skin. Utilizing this model, we were able to quantify the concentrations of key intracellular folate species during folate depletion and repletion. We investigated the hypotheses that the genomic instability observed under conditions of folate deficiency in other cell types extends to skin, adversely effecting cellular capacity to handle UVR insult and that optimizing folate levels in skin is beneficial in preventing or repairing the pro-carcinogenic effects of UVR exposure. Folate restriction leads to rapid depletion of intracellular reduced folates resulting in S-phase growth arrest, increased levels of inherent DNA damage, and increased uracil misincorporation into DNA, without a significant losses in overall cellular viability. Folate depleted keratinocytes were sensitized toward UVR induced apoptosis and displayed a diminished capacity to remove DNA breaks resulting from both photo and oxidative DNA damage. Thus, folate deficiency creates a permissive environment for genomic instability, an early event in the process of skin carcinogenesis. The effects of folate restriction, even in severely depleted, growth-arrested keratinocytes, were reversible by repletion with folic acid. Overall, these results indicate that skin health can be positively influenced by optimal folate nutriture.

Topics: Cell Line; Comet Assay; DNA Damage; Folic Acid; Folic Acid Deficiency; Genomic Instability; Humans; Keratinocytes; S Phase; Tetrahydrofolates; Ultraviolet Rays; Uracil

To investigate the efficiency of [6S]-5-methyltetrahydrofolate or Metafolin ([6S]-5-CH(3)-H(4)folate) on the recovery of folate status, we conducted a depletion-repletion rat model study using a growing-up milk as the folate carrier.. The effect of [6S]-5-CH(3)-H(4)folate was compared to that of folic acid (PGA or Pte-Glu), by feeding two groups of folate-depleted rats a diet of fortified growing-up milk containing either 1,000 microg/l (2.2655 micromol/l) of Pte-Glu or 1,041.91 microg/l (2.2655 micromol/l) of [6S]-5-CH(3)-H(4)folate over a 4-week period. At the end of the study, the folate concentration in plasma, erythrocytes and liver was measured to establish the folate status of the animals. The folate content was determined in the plasma and erythrocytes by a time-resolved fluoroimmunoassay method and in the liver by a HPLC method.. Plasma, erythrocyte and liver folate concentrations were significantly (P < 0.001) lower after a depletion period in rats fed the folate-deficient diet compared to rats fed a control diet. The folate form used significantly influenced the folate concentration in erythrocytes and liver, but not in plasma, after the rats' body folate reserves were replenished by consuming the fortified growing-up milk. Thus, rats fed [6S]-5-CH(3)-H(4)folate-fortified growing-up milk showed significantly higher folate content in erythrocytes and liver (1,100.37 ng/ml and 4.22 microg/g, respectively), than did those fed Pte-Glu-fortified growing-up milk (827.71 ng/ml and 3.04 microg/g, respectively, in erythrocytes and liver).. We conclude that the natural diastereomer [6S]-5-CH(3)-H(4)folate may adequately serve as an alternative to folic acid for the folate fortification of infant foods.

Topics: Analysis of Variance; Animals; Animals, Newborn; Body Weight; Diet; Erythrocytes; Folic Acid; Folic Acid Deficiency; Infant Formula; Limit of Detection; Liver; Male; Nutritional Status; Random Allocation; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Stereoisomerism; Tetrahydrofolates

We studied seven children with CNS folate deficiency (CFD). All cases exhibited psychomotor retardation, regression, cognitive delay, and dyskinesia; six had seizures; four demonstrated neurological abnormalities in the neonatal period. Two subjects had profound neurological abnormalities that precluded formal behavioral testing. Five subjects received ADOS and ADI-R testing and met diagnostic criteria for autism or autism spectrum disorders. They exhibited difficulties with transitions, insistence on sameness, unusual sensory interests, and repetitive behaviors. Those with the best language skills largely used repetitive phrases. No mutations were found in folate transporter or folate enzyme genes. These findings demonstrate that autistic features are salient in CFD and suggest that a subset of children with developmental regression, mental retardation, seizures, dyskinesia, and autism may have CNS folate abnormalities.

Topics: Adolescent; Autistic Disorder; Brain; Child; Child, Preschool; Developmental Disabilities; Dyskinesias; Epilepsy; Female; Folic Acid; Folic Acid Deficiency; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Pregnancy; Psychomotor Disorders; Reference Values; Regression, Psychology; Tetrahydrofolates

Isolated cerebral folate deficiency was detected in a 13-year-old girl with cognitive and motor difficulties and juvenile rheumatoid arthritis. Her serum contains autoantibodies that block membrane-bound folate receptors that are on the choroid plexus and diminish the uptake of folate into the spinal fluid. Whereas her serum folate exceeded 21 ng/mL, her spinal fluid contained 3.2 ng/mL of 5-methyltetrahydrofolate as a consequence of the autoantibodies diminishing the uptake of this folate.

Topics: Adolescent; Affective Symptoms; Age of Onset; Arthritis, Juvenile; Autoantibodies; Brain; Brain Diseases, Metabolic; Carrier Proteins; Choroid Plexus; Cognition Disorders; Female; Folate Receptors, GPI-Anchored; Folic Acid; Folic Acid Deficiency; Humans; Magnetic Resonance Imaging; Motor Skills Disorders; Receptors, Cell Surface; Spinal Cord; Tetrahydrofolates

Topics: Adolescent; Adult; Brain; Child; Child, Preschool; Female; Folic Acid Deficiency; Humans; Infant; Male; Mitochondrial Diseases; Tetrahydrofolates

Topics: Antiparkinson Agents; Atrophy; Basal Ganglia; Brain Diseases, Metabolic; Carbidopa; Cerebellum; Demyelinating Diseases; Dystonia; Female; Folic Acid Deficiency; Humans; Leucovorin; Levodopa; Male; Syndrome; Tetrahydrofolates; Treatment Outcome; Vitamin B Complex

This laboratory recently identified a human gene that encodes a novel folate transporter [Homo sapiens proton-coupled folate transporter (HsPCFT); SLC46A1] required for intestinal folate absorption. This study focused on mouse (Mus musculus) PCFT (MmPCFT) and rat (Rattus norvegicus) PCFT (RnPCFT) and addresses their secondary structure, specificity, tissue expression, and regulation by dietary folates. Both rodent PCFT proteins traffic to the cell membrane with the NH(2)- and COOH-termini accessible to antibodies targeted to these domains only in permeabilized HeLa cells. This, together with computer-based topological analyses, is consistent with a model in which rodent PCFT proteins likely contain 12 transmembrane domains. Transport of [(3)H]folates was optimal at pH 5.5 and decreased with increasing pH due to an increase in K(m) and a decrease in V(max). At pH 7.0, folic acid and methotrexate influx was negligible, but there was residual (6S)5-methyltetrahydrofolate transport. Uptake of folates in PCFT-injected Xenopus oocytes was electrogenic and pH dependent. Folic acid influx K(m) values of MmPCFT and RnPCFT, assessed electrophysiologically, were 0.7 and 0.3 microM at pH 5.5 and 1.1 and 0.8 microM at pH 6.5, respectively. Rodent PCFTs were highly specific for monoglutamyl but not polyglutamyl methotrexate. MmPCFT mRNA was highly expressed in the duodenum, proximal jejunum, liver, and kidney with lesser expression in the brain and other tissues. MmPCFT protein was localized to the apical brush-border membrane of the duodenum and proximal jejunum. MmPCFT mRNA levels increased approximately 13-fold in the proximal small intestine in mice fed a folate-deficient vesus folate-replete diet, consistent with the critical role that PCFT plays in intestinal folate absorption.

Topics: Amino Acid Sequence; Animals; Anion Transport Proteins; Cell Membrane; Disease Models, Animal; Folic Acid; Folic Acid Antagonists; Folic Acid Deficiency; HeLa Cells; Humans; Hydrogen-Ion Concentration; Intestine, Small; Kinetics; Male; Membrane Potentials; Membrane Transport Proteins; Methotrexate; Mice; Mice, Inbred C57BL; Microvilli; Molecular Sequence Data; Oocytes; Polyglutamic Acid; Protein Structure, Secondary; Protein Structure, Tertiary; Protein Transport; Proton-Coupled Folate Transporter; Rats; RNA, Messenger; Tetrahydrofolates; Xenopus

Reduced folate transport to the CNS was identified in two autism spectrum disorders, i.e., Rett syndrome and infantile low-functioning autism with neurological abnormalities. Twenty-five patients with early-onset low-functioning autism with or without neurological deficits, were evaluated for serum folate, cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF), and serum FR autoantibodies of the blocking type to determine the significance of folate receptor (FR) autoantibodies with respect to folate transport across the blood-CSF barrier. In spite of normal serum folate, CSF 5MTHF was low in 23 of 25 patients. The reduced CSF folate in 19 of these 23 patients could be explained by serum FR autoantibodies blocking the folate binding site of the membrane-attached FR on the choroid epithelial cells. Oral folinic acid supplements led to normal CSF 5MTHF and partial or complete clinical recovery after 12 months. Serum FR autoimmunity appears to represent an important factor in the pathogenesis of reduced folate transport to the nervous system among children with early-onset low-functioning autism associated with or without neurological deficits. Early detection of FR autoantibodies may be a key factor in the prevention and therapeutic intervention among this subgroup of patients with autism.

Topics: Adolescent; Autistic Disorder; Autoantibodies; Carrier Proteins; Child; Child, Preschool; Female; Folate Receptors, GPI-Anchored; Folic Acid; Folic Acid Deficiency; Humans; Male; Nervous System Diseases; Receptors, Cell Surface; Tetrahydrofolates; Treatment Outcome

Cerebral folate deficiency is characterized by low cerebrospinal fluid (CSF) concentrations of 5-methyltetrahydrofolate and a broad spectrum of clinical signs and symptoms. A patient with progressive spasticity, gait disturbance, speech difficulties, initially diagnosed as a recessive spastic paraplegia recovered on folinic acid (15-30 mg/day) and her 5-methyltetrahydrofolate in CSF normalized. This report demonstrates the importance of CSF investigation in the diagnosis of cerebral folate deficiency and efficiency of folinic acid (5-formyltetrahydrofolate) supplementation.

Topics: Brain Diseases; Child; Child, Preschool; Dietary Supplements; Dose-Response Relationship, Drug; Female; Folic Acid Deficiency; Gait; Humans; Leucovorin; Life Style; Movement Disorders; Paraplegia; Pregnancy; Speech Disorders; Tetrahydrofolates

The authors describe a 6-year-old girl with developmental delay, psychomotor regression, seizures, mental retardation, and autistic features associated with low CSF levels of 5-methyltetrahydrofolate, the biologically active form of folates in CSF and blood. Folate and B12 levels were normal in peripheral tissues, suggesting cerebral folate deficiency. Treatment with folinic acid corrected CSF abnormalities and improved motor skills.

Topics: Adaptation, Physiological; Autistic Disorder; Cerebral Cortex; Child; Developmental Disabilities; Disease Progression; Female; Folic Acid; Folic Acid Deficiency; Genetic Predisposition to Disease; Humans; Intellectual Disability; Leucovorin; Mutation; Recovery of Function; Reduced Folate Carrier Protein; Seizures; Tetrahydrofolates; Transcription Factors; Treatment Outcome

In infantile-onset cerebral folate deficiency, 5-methyltetrahydrofolate (5MTHF) levels in the cerebrospinal fluid are low, but folate levels in the serum and erythrocytes are normal. We examined serum specimens from 28 children with cerebral folate deficiency, 5 of their mothers, 28 age-matched control subjects, and 41 patients with an unrelated neurologic disorder. Serum from 25 of the 28 patients and 0 of 28 control subjects contained high-affinity blocking autoantibodies against membrane-bound folate receptors that are present on the choroid plexus. Oral folinic acid normalized 5MTHF levels in the cerebrospinal fluid and led to clinical improvement. Cerebral folate deficiency is a disorder in which autoantibodies can prevent the transfer of folate from the plasma to the cerebrospinal fluid.

Topics: Adolescent; Adult; Autoantibodies; Autoimmune Diseases; Biological Transport; Blood-Brain Barrier; Carrier Proteins; Case-Control Studies; Child; Child, Preschool; Choroid Plexus; Female; Folate Receptors, GPI-Anchored; Folic Acid; Folic Acid Deficiency; Humans; Male; Receptors, Cell Surface; Tetrahydrofolates

Topics: Adolescent; Adult; Biomarkers; Blood-Brain Barrier; Brain; Cerebrospinal Fluid; Child; Child, Preschool; Female; Folic Acid; Folic Acid Deficiency; Humans; Leucovorin; Predictive Value of Tests; Reference Values; Rett Syndrome; Tetrahydrofolates; Treatment Outcome

Topics: Autoantibodies; Autoimmune Diseases; Biological Transport; Diagnosis, Differential; Folic Acid; Folic Acid Deficiency; Humans; Infant; Receptors, Cell Surface; Rett Syndrome; Tetrahydrofolates

Topics: Folic Acid Deficiency; Humans; Mental Disorders; Tetrahydrofolates

The effect of azidothymidine (Zidovudine, AZT) on pyrimidine (thymidine, deoxyuridine, and thymidine triphosphate) incorporation into DNA in folate- and/or vitamin B12-deficient and normal human bone marrow cells was studied to investigate whether such vitamin deficiency affects susceptibility to AZT-induced hematologic toxicity. Bone marrow cells from 12 patients were studied: 5 had folate and/or vitamin B12 deficiency; 7 controls included 5 with anemia related to chronic disease and 2 with iron deficiency. At 0.2 microM AZT (3 hr, 37 degrees C), the approximate pharmacologic serum trough level, pyrimidine incorporation into DNA was suppressed by 12 to 19% in folate- and/or vitamin B12-deficient cells and by 16 to 23% in normal cells. At 2.0 microM AZT (3 hr, 37 degrees C), the approximate pharmacologic serum peak level, this was suppressed by 15 to 40% in folate- and/or vitamin B12-deficient cells and by 32 to 47% in controls. Deoxyuridine incorporation into DNA was inhibited significantly greater than thymidine at 2.0 microM AZT (3 hr, 37 degrees C) in both groups. Inhibition of deoxyuridine incorporation was not reversed with methyltetrahydrofolate or vitamin B12. There tended to be less striking suppression by AZT of deoxyuridine incorporation into DNA in bone marrow cells from vitamin B12-deficient patients, which was made more striking by adding vitamin B12. This suggests that some of what passes for "AZT damage" to bone marrow cells may in fact be coincident deficiency of vitamin B12. AZT inhibition of DNA synthesis in 3 hr bone marrow cultures is relatively consistent in a variety of hematologic disorders. As approximately two-thirds of AIDS patients appear to be in negative balance with respect to folate and/or vitamin B12, the fact that AZT-induced inhibition of pyrimidine incorporation into DNA is occurring in cells which may be megaloblastic, i.e., in a state of impaired DNA synthesis, suggests that these cells may be more susceptible to AZT toxicity. The data also support the notion that AZT inhibition results predominantly from termination of DNA chain elongation. Whether folate or vitamin B12 supplementation may partially overcome apparent "AZT inhibition" of DNA synthesis (hematologic toxicity) and whether the benefit of such therapy exceeds the risk will require further study.

Topics: Bone Marrow; Deoxyuridine; DNA; Folic Acid Deficiency; Humans; Pyrimidines; Tetrahydrofolates; Thymidine; Vitamin B 12 Deficiency; Zidovudine

Acute ethanol treatment enhances the urinary excretion of endogenous folate. This effect has been implicated in the development of folate deficiency associated with chronic alcoholism. Previous studies have shown that urinary excretion of total [3H]-label after administration of [3H]folic acid is slightly higher in ethanol-treated rats because of conversion of the tracer to forms whose excretion is not affected by ethanol. Since [3H]folic acid is not the physiological substrate for the kidney, studies were performed using a high specific activity 5-methyltetrahydrofolic acid ([3H]5-CH3-H4 folic acid). Male Sprague-Dawley rats were given four consecutive hourly doses of ethanol at 1 g/kg, followed by infusion of [3H]5-CH3-H4 folic acid at 5 h. Urine samples were collected to 6 h, when rats were killed, and plasma, liver and kidney samples were collected. Endogenous urinary folate excretion and the fractional urinary excretion of both endogenous and [3H]5-CH3-H4 folic acid at the 5-6 h time period were significantly higher in ethanol-treated rats. The kidney had a tenfold greater specific incorporation of [3H]-label than did the liver. High performance liquid chromatography (HPLC) analysis of the plasma obtained at 6 h showed that 68% of the label was [3H]5-CH3-H4 folic acid, and HPLC analysis of the urine obtained from 5-6 h showed that only 10% of the label was [3H]5-CH3-H4 folic acid. The data indicate that [3H]5-CH3-H4 folic acid was rapidly taken up by the kidney and metabolized to other folate and nonfolate forms, which were then secreted into the renal tubule for excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alcoholism; Animals; Chromatography, High Pressure Liquid; Ethanol; Folic Acid; Folic Acid Deficiency; Kidney; Liver; Male; Plasma; Rats; Rats, Inbred Strains; Tetrahydrofolates

We performed studies in 25 patients with low serum cobalamin levels who had few if any clinical or hematologic findings of cobalamin deficiency. All but three had morphologically normoblastic hematopoiesis, and 15 were not even anemic. None of those tested excreted methylmalonic acid or homocystine. Nevertheless, the dUST identified metabolic abnormalities in 18 of the 25 cases. In vitro additives were essential in the dUST. Especially noteworthy was MTHF, whose addition unmasked an otherwise undetectable dUST abnormality in four cases. Why MTHF appears to act as a "stress test" in this setting is unknown but deserves further attention. Seven patients had early forms of classical malabsorptive states such as pernicious anemia, defined by abnormal Schilling test results. Among the rest, seven of 13 patients displayed malabsorption of protein-bound cobalamin despite normal absorption of free cobalamin by the Schilling test. In two patients, initially normal Schilling test results became abnormal the following year. These findings demonstrate that seemingly falsely low serum cobalamin levels often indicate subtle biochemical cobalamin deficiency. Early stages of pernicious anemia or other classical malabsorptive states are sometimes responsible for such subtle deficiency. However, malabsorption confined to protein-bound cobalamin is an equally common cause. Current concepts of cobalamin deficiency and the absorptive defects that can cause it should be expanded to include atypical defects requiring newer methods of identification.

Topics: Adult; Aged; Aged, 80 and over; Bone Marrow; Deoxyuridine; Female; Folic Acid Deficiency; Humans; In Vitro Techniques; Intestinal Absorption; Male; Middle Aged; Prospective Studies; Protein Binding; Tetrahydrofolates; Vitamin B 12; Vitamin B 12 Deficiency

Folate deficiency and megaloblastic anemia occur in chronic renal failure. However, the possible role of intestinal malabsorption as a cause of the reported deficiency has not been investigated. Therefore, we examined the intestinal absorption of 5-methyltetrahydrofolate in rats made uremic by subtotal nephrectomy using in vivo perfusion technique and in vitro everted sac technique. The results were compared with those obtained in a group of sham-operated rats with normal renal function. The amount of 5-methyltetrahydrofolate absorbed in vivo was significantly lower in the uremic animals as compared to the control group. In contrast, no significant difference was found in the absorption of 5-methyltetrahydrofolate in vitro in the two groups. To mimic the uremic environment, the in vitro studies were repeated using jejunal sacs from normal animals filled with either buffer solution, or sera from uremic patients before and after dialysis. Their results showed a marked suppression of 5-methyltetrahydrofolate absorption with predialysis sera and a significant improvement with post dialysis sera. We conclude that intestinal absorption of 5-methyltetrahydrofolate is impaired in uremia. The results of the in vitro experiments suggest that the observed transport defect is due to some influence of uremic environment rather than to an acquired intrinsic defect of enterocytes in uremia.

Topics: Anemia, Megaloblastic; Animals; Biological Transport; Folic Acid Deficiency; In Vitro Techniques; Intestinal Absorption; Male; Rats; Rats, Inbred Strains; Tetrahydrofolates; Uremia

The role of vitamin B12 in the folate dependent biosynthesis of thymidine nucleotides is controversial. In an attempt to clarify this, three methods have been used to assess the relative efficacy of vitamin B12 (hydroxocobalamin) and various folate analogues in titrated concentrations at correcting 'de novo' thymidylate synthesis by megaloblastic human marrow cells: (1) The deoxyuridine (dU) suppression test which analyses the reduction in (3H)-thymidine labeling of DNA by unlabeled dU. Marrow cells were also labeled with (6-3H)-dU with assessment of (2) its incorporation into DNA and (3) the accumulation of (6-3H)-deoxyuridine monophosphate (3H-dUMP). The three methods gave similar results. In both, N6-formyl tetrahydrofolate (formyl-FH4) was the most effective agent at correcting thymidylate synthesis in megaloblastic anemia due to vitamin B12 or folate deficiency. Vitamin B12 corrected the lesion in vitamin B12 deficiency but not in folate deficiency. Tetrahydrofolate (FH4) and folic acid were effective in deficiency of vitamin B12 or folate, although in both deficiencies they were less effective than formyl-FH4. Methyl-FH4 was effective in folate deficiency but not in vitamin B12 deficiency. These results confirm the failure of methyl-FH4 utilisation in vitamin B12 deficiency. They suggest that if vitamin B12 is needed in the formylation of FH4, this is a minor role in provision of the correct coenzyme for thymidylate synthesis compared with its major role of provision of FH4 from methyl-FH4.

Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Bone Marrow; Deoxyuridine; DNA; Folic Acid; Folic Acid Deficiency; Humans; Leucovorin; Tetrahydrofolates; Thymine Nucleotides; Vitamin B 12; Vitamin B 12 Deficiency

Rats were injected with [2-14C]H4PteGlu daily for 3 d and thereafter one group left in air and a second group in an atmosphere of nitrous oxide/oxygen (1/1). Nitrous oxide inactivates cobalamin. The N2O-treated rats excreted large amounts of L. casei-active folate into the urine. The urinary folate co-chromatographed with authentic 3H-labelled 5-methyltetrahydrofolate. Both groups of animals excreted 14C-labelled breakdown products in the urine but there was no evidence of increased folate catabolism in the N2O-treated rats. It was concluded that the folate deficiency that develops in the N2O-treated rat is due to massive urinary loss of folate. This appears to be secondary to impaired cellular uptake of folate which leads to a raised plasma folate level.

Topics: Animals; Chromatography, DEAE-Cellulose; Folic Acid; Folic Acid Deficiency; Liver; Male; Nitrous Oxide; Rats; Rats, Inbred Strains; Tetrahydrofolates; Time Factors; Vitamin B 12