Cerebral folate deficiency: a treatable cause of late deterioration in epilepsy with developmental delay.

A 25-year-old woman with childhood-onset refractory epilepsy and developmental delay experienced a gradually progressive marked deterioration in mobility and seizure control, with language regression. Investigation identified a homozygous deletion within the contactin-associated protein-like 2 gene (CNTNAP2), underlying her early presentation, but also cerebral folate deficiency that most likely contributed to her later deterioration. Following antiseizure medication adjustment and treatment with folinic acid, she stabilised with improved seizure control and limited improvement in language and motor function; she has remained neurologically stable for more than a decade. That the previously observed neurological decline was halted by folinic acid replacement supports this being due to cerebral folate deficiency. Metabolic conditions are less well recognised in adults and can be under-diagnosed. They are potentially treatable and should be considered even in the presence of another cause, particularly when the presentation is not fully compatible.

Folic Acid Supplementation to Prevent Neural Tube Defects: US Preventive Services Task Force Reaffirmation Recommendation Statement.

Importance: Neural tube defects are among the most common congenital malformations in the US, with an estimated 3000 pregnancies affected each year. Many of these neural tube defects are caused by low folate levels in the body. Objective: The US Preventive Services Task Force (USPSTF) commissioned a reaffirmation evidence update on the benefits and harms of folic acid supplementation. Population: Persons who are planning to or could become pregnant. Evidence Assessment: The USPSTF concludes that, for persons who are planning to or could become pregnant, there is high certainty that folic acid supplementation has a substantial net benefit to prevent neural tube defects in their offspring. Recommendation: The USPSTF recommends that all persons planning to or who could become pregnant take a daily supplement containing 0.4 to 0.8 mg (400 to 800 µg) of folic acid. (A recommendation).

Hypomyelination caused by a novel homozygous pathogenic variant in FOLR1: complete clinical and radiological recovery with oral folinic acid therapy and review of the literature.

BACKGROUND: Neurodegeneration due to cerebral folate transport deficiency is a rare autosomal recessive disorder caused by biallelic pathogenic variants in FOLR1. Onset typically occurs in late infancy and is characterized by psychomotor regression, epilepsy, and a hypomyelinating leukodystrophy on magnetic resonance imaging. If left untreated, progressive neurodegeneration occurs. However, early treatment with folinic acid has been shown to stabilize or reverse neurological features. Approximately thirty patients have been described worldwide. Here, we report the first two cases with genetically proven cerebral folate transport deficiency from South-Eastern Europe, describe the effect of oral folinic acid therapy on clinical and neuroradiological features and review the literature. RESULTS: Two siblings presented in childhood with clinical and radiological findings consistent with a hypomyelinating leukodystrophy. Exome sequencing revealed a novel homozygous pathogenic variant in FOLR1 (c.465_466delinsTG; p.W156G), confirming the diagnosis of neurodegeneration due to cerebral folate transport deficiency. Folinic acid treatment was promptly initiated in both patients. The younger sibling was treated early in disease course at 2 years of age, and demonstrated complete recovery in clinical and MRI features. The older sibling, who was 8 years of age at the time of diagnosis and treatment, demonstrated partial but substantial improvements. CONCLUSION: We present the first account in the literature that early treatment initiation with oral folinic acid alone can result in complete neurological recovery of both clinical and radiological abnormalities in neurodegeneration due to cerebral folate deficiency. Moreover, through the report of these patients along with review of the literature, we provide information about the natural history of the disease with comparison of treatment effects at different stages of disease progression. This report also reinforces the importance of universal access to genetic testing to ensure prompt diagnoses for treatable disorders.

Cerebral folate transporter deficiency: a potentially treatable neurometabolic disorder.

Cerebral folate deficiency (CFD) syndrome is a rare treatable neurometabolic disorder with low levels of the active form of folaten in cerebrospinal fluid (CSF) arising from different causes such as FOLR1 gene mutations or autoantibodies against the folate receptor-alpha (FR) protein that can block folate transport across the choroid plexus. It is characterized by late infantile onset refractory seizures, ataxia, movement disorder, and unexplained global developmental delay. Here, we report a patient diagnosed with autistic spectrum disorder, followed by refractory myoclonic-atonic seizures, ataxia, and loss of motor skills over time. A homozygous missense (c.665A > G) mutation in FOLR1 gene and extremely low CSF 5-methyltetrahydrofolate level led to the diagnosis of CFD. Although she was initiated on combined oral and intravenous high doses of folinic acid treatment at 6 years of age, mild improvement was achieved in terms of epileptic seizures and motor skills. It is important that CFD should be kept in mind in cases with refractory myoclonic-atonic seizure and folinic acid treatment should be started as soon as possible.

Combined action of SAMe, Folate, and Vitamin B12 in the treatment of mood disorders: a review.

Mood disorders affect more than 500 million people around the world. In the last decade, their prevalence has increased, and many people suffer from nervousness, anxiety, and stress at least once in their lives. The incidence of mood disorders and anxiety increases during perimenopause or under stressful conditions. The social restrictions introduced during the COVID-19 pandemic have significantly increased the normal burden of psychological and psychic disorders. In moderate to severe cases, pharmacological treatment is currently recommended, while in mild disorders, especially in the initial phase, psychological therapy is preferable. It is known that several nutrients are crucial for brain function. Among them, folate (vitamin B9), cyanocobalamin (vitamin B12), and S-adenosyl-L-methionine (SAMe) have been shown to influence various neurobiological processes. Overall, the available evidence suggests that dietary supplementation with folic acid, vitamin B12, and SAMe can be beneficial for people with mild mood disorders.

Hyperhomocysteinemia-related serum metabolome alterations not normalized by short-term folic acid treatment.

INTRODUCTION: Hyperhomocysteinemia (HHCys) is an independent risk factor for various diseases such as cardiovascular diseases, Alzheimer's, and cancers. Folate deficiency is one of the significant reasons for HHCys. However, it is not known whether folate deficiency with HHCys is associated with any serum metabolites. OBJECTIVES: Our objective was to identify the metabolic alterations in people having folate deficiency with HHCys and check whether a short-term folic acid therapy could reverse those metabolic changes. METHODS: The study enrolled 34 participants aged between 18 and 40 years having folate deficiency (< 4.6 ng/mL) with HHCys (> 15 µmol/L) and 21 normal healthy individuals. A short-term intervention of oral folic acid (5 mg/day) was done in the HHCys group for 30 days. Untargeted metabolomics analysis of serum was performed in all study subjects before and after the folic acid treatment. Different univariate methods and the multivariable-adjusted linear regression models were employed to determine an association between homocysteine level and metabolite profile. RESULTS: Metabolomics analysis data showed that many metabolites involved in the biochemical pathways of lipid metabolisms such as polyunsaturated fatty acids, glycerolipids, and phospholipids were downregulated in the HHCys group. Short-term oral folic acid therapy significantly reduced their serum homocysteine level. However, the metabolic pathway alterations observed in folate-deficient HHCys-condition were unaltered even after the folic acid treatment. CONCLUSIONS: Our study revealed that people who have a folic acid deficiency with HHCys have an altered metabolite profile related to lipid metabolism, which cannot be reversed by short-term folic acid therapy.

The effects of folate and iron deficiency followed by supplementation on blood morphology and inflammation biomarkers in rats.

BACKGROUND: Little is known about the relation between iron and folic acid (FA) supplementation and inflammation. The aim of this study was to evaluate the effects of iron and folate deficiency and supplementation on blood morphology parameters, and to assess the role of iron and folate transporters in inflammation. METHODS: A four-week period of FA and iron deficiency in Wistar rats was followed by randomization into a group fed with a diet deficient in FA and supplemented with Fe (DFE), a group fed a diet deficient in Fe and supplemented with FA (DFOL), a group fed a diet supplemented with Fe and FA (FEFOL), a group fed a diet deficient in Fe and FA (D), and a group fed a control diet (C). The blood Crp concentration and blood count were determined. The expression of SLC11A2, SLC46A1, SLC19A1, and TFR2 proteins was assessed using the western blot method. RESULTS: After ten days on the experimental diets, the rats in the DFOL group had a 21% higher concentration of white blood cells (WBC) than the FEFOL group did (p < 0.05). We did not observe any differences between the groups in terms of C-reactive protein (Crp) concentration. We also did not find any other differences between the groups in other morphological parameters. Analysis of the correlation between blood count parameters and the expression of iron and folate transporters gave conflicting results. CONCLUSIONS: To conclude, iron and folate supplementation may affect WBC concentration in the blood.

Epidemiology and (Patho)Physiology of Folic Acid Supplement Use in Obese Women before and during Pregnancy.

Preconception folic acid supplement use is a well-known method of primary prevention of neural tube defects (NTDs). Obese women are at a higher risk for having a child with a NTD. As different international recommendations on folic acid supplement use for obese women before and during pregnancy exist, this narrative review provides an overview of epidemiology of folate deficiency in obese (pre)pregnant women, elaborates on potential mechanisms underlying folate deficiency, and discusses considerations for the usage of higher doses of folic acid supplements. Women with obesity more often suffer from an absolute folate deficiency, as they are less compliant to periconceptional folic acid supplement use recommendations. In addition, their dietary folate intake is limited due to an unbalanced diet (relative malnutrition). The association of obesity and NTDs also seems to be independent of folate intake, with studies suggesting an increased need of folate (relative deficiency) due to derangements involved in other pathways. The relative folate deficiency, as a result of an increased metabolic need for folate in obese women, can be due to: (1) low-grade chronic inflammation (2) insulin resistance, (3) inositol, and (4) dysbiotic gut microbiome, which plays a role in folate production and uptake. In all these pathways, the folate-dependent one-carbon metabolism is involved. In conclusion, scientific evidence of the involvement of several folate-related pathways implies to increase the recommended folic acid supplementation in obese women. However, the physiological uptake of synthetic folic acid is limited and side-effects of unmetabolized folic acid in mothers and offspring, in particular variations in epigenetic (re)programming with long-term health effects, cannot be excluded. Therefore, we emphasize on the urgent need for further research and preconception personalized counseling on folate status, lifestyle, and medical conditions.

[Chorioretinal atrophy in pediatric cerebral folate deficiency-a preventable disease?] / Chorioretinale Atrophie bei kindlichem zerebralem Folatmangel ­ eine vermeidbare Erkrankung?

Cerebral folate deficiency (CFD) results in neurological alterations and a massive degeneration of the choroid/retina if left untreated, which limit the visual field and visual acuity. This article reports the case of a female patient with CFD, who developed autistic personal characteristics prior to reaching school age and first started to speak at the age of 3 years. At the age of 6 years she was presented because of unclear reduced visual acuity in the right eye. At that time mild bilateral peripheral chorioretinal atrophy was present, which subsequently became more pronounced. Additionally, a centrally emphasized chorioretinal atrophy further developed. Visual acuity of both eyes progressively deteriorated until stagnating at 0.1 at the age of 14 years. The causal assignment of the findings of the patient was not possible for many years. Choroideremia was excluded by molecular genetic testing (CHM gene with no mutations) and gyrate atrophy was ruled out by a normal ornithine level. The existence of a mitochondrial disease was almost completely excluded by exome sequencing. After the onset of further nonocular symptoms, e.g. neuromuscular disorders, electroencephalograph (EEG) alterations and autistic disorder, intensified laboratory diagnostics were performed in the treating pediatric hospital. Finally, an extremely low level of the folic acid metabolite 5­methyltetrahydrofolate was detected in the cerebrospinal fluid (CSF) leading to the diagnosis of CFD. High-dose substitution treatment with folic acid was subsequently initiated. After excluding the presence of a pathogenic mutation of the FOLR1 gene for the cerebral folate receptor 1, a high titer blocking autoantibody against cerebral folate receptor 1 was detected as the cause.

First case report of cerebral folate deficiency caused by a novel mutation of FOLR1 gene in a Chinese patient.

BACKGROUND: 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. CASE PRESENTATION: 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. CONCLUSIONS: 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.

Treatment of Folate Metabolism Abnormalities in Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that currently has no approved medical therapy to address core symptoms or underling pathophysiological processes. Several compounds are under development that address both underlying pathophysiological abnormalities and core ASD symptoms. This article reviews one of these treatments, d,l-leucovorin calcium (also known as folinic acid) for treatment of folate pathway abnormalities in children with ASD. Folate is a water-soluble B vitamin that is essential for normal neurodevelopment and abnormalities in the folate and related pathways have been identified in children with ASD. One of these abnormalities involves a partial blockage in the ability of folate to be transported into the brain utilizing the primary transport mechanism, the folate receptor alpha. Autoantibodies which interfere with the function of the folate receptor alpha called folate receptor alpha autoantibodies have been identified in 58%-76% of children with ASD and independent studies have demonstrated that blood titers of these autoantibodies correlate with folate levels in the cerebrospinal fluid. Most significantly, case-series, open-label, and single and double-blind placebo-controlled studies suggest that d,l-leucovorin, a reduced folate that can bypass the blockage at the folate receptor alpha by using the reduced folate carrier, an alternate pathway, can substantially improve particular symptoms in children with ASD, especially those positive for folate receptor alpha autoantibodies. This article reviews the current evidence for treating core and associated symptoms and underlying pathophysiological mechanisms in children with ASD with d,l-leucovorin.

Vitamin B12 and folic acid alleviate symptoms of nutritional deficiency by antagonizing aryl hydrocarbon receptor.

Despite broad appreciation of their clinical utility, it has been unclear how vitamin B12 and folic acid (FA) function at the molecular level to directly prevent their hallmark symptoms of deficiency like anemia or birth defects. To this point, B12 and FA have largely been studied as cofactors for enzymes in the one-carbon (1C) cycle in facilitating the de novo generation of nucleotides and methylation of DNA and protein. Here, we report that B12 and FA function as natural antagonists of aryl hydrocarbon receptor (AhR). Our studies indicate that B12 and FA bind AhR directly as competitive antagonists, blocking AhR nuclear localization, XRE binding, and target gene induction mediated by AhR agonists like 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and 6-formylindolo[3,2-b]carbazole (FICZ). In mice, TCDD treatment replicated many of the hallmark symptoms of B12/FA deficiency and cotreatment with aryl hydrocarbon portions of B12/FA rescued mice from these toxic effects. Moreover, we found that B12/FA deficiency in mice induces AhR transcriptional activity and accumulation of erythroid progenitors and that it may do so in an AhR-dependent fashion. Consistent with these results, we observed that human cancer samples with deficient B12/FA uptake demonstrated higher transcription of AhR target genes and lower transcription of pathways implicated in birth defects. In contrast, there was no significant difference observed between samples with mutated and intact 1C cycle proteins. Thus, we propose a model in which B12 and FA blunt the effect of natural AhR agonists at baseline to prevent the symptoms that arise with AhR overactivation.

Estomatitis aftosa recurrente y deficiencias nutricionales: Reporte de tres casos y revisión de literatura / Recurrent Aphthous Stomatitis and Nutritional Deficiencies: Report of Three Cases with Literature Review

RESUMEN Introducción: La estomatitis aftosa recurrente (EAR) es la enfermedad ulcerativa más común que afecta la mucosa oral no queratinizada. La etiología aún se desconoce, pero se han propuesto varios factores locales y sistémicos como agentes causales. Descripción del caso: se informa tres pacientes con presencia de EAR asociada a deficiencias nutricionales, debidas a dietas de restricción alimentaria. El primer caso, una mujer de 19 años con deficiencia de hierro, refirió tomar té verde a diario y consumir poca cantidad de carbohidratos, grasas y carne. El segundo caso, un hombre de 32 años con deficiencia de hierro y vitamina B12 asociada a dieta tipo vegana, aunque a veces si consumía carne. El tercer caso, hombre de 50 años, vegano y exfumador desde hace un año, presentó deficiencia de hierro, vitamina B12 y ácido fólico. En los tres casos un detallado interrogatorio, examen clínico y análisis sanguíneo completo, permitió establecer un adecuado diagnóstico, manejo odontológico y derivación con un nutricionista, con el fin de tratar la patología de base y no sólo brindarles un tratamiento sintomático de las lesiones. Discusión: Ante un cuadro de EAR es recomendable realizar un análisis que incluya hemograma, ácido fólico, hierro y vitamina B12, para descartar posibles causas sistémicas y eventualmente tratarlas. El manejo clínico tiene como objetivo mejorar la función del paciente y la calidad de vida mediante terapias tópicas y sistémicas; sin embargo, es fundamental identificar y controlar los factores causales que contribuyen; así como, la exclusión o tratamiento de la enfermedad sistémica subyacente.

ABSTRACT Introduction: Recurrent aphthous stomatitis (RAS) is the most common ulcerative disease that affects the non-keratinized oral mucosa. The etiology is still unknown, but several local and systemic factors have been proposed as causal agents. Case description: three patients are reported with RAS associated with nutritional deficiencies, due to dietary restriction diets. The first case, a 19-year- old woman with iron deficiency, reported taking green tea daily and consuming a small amount of carbohydrates, fats and meat. The second case, a 32-year-old man with iron deficiency and vitamin B12 associated with vegan diet, although sometimes if he consumed meat. The third case, man of 50 years, vegan and ex-smoker for a year, presented deficiency of iron, vitamin B12 and folic acid. In all three cases a detailed questioning, clinical examination and complete blood analysis allowed to establish an adequate diagnosis, dental management and referral with a nutritionist, in order to treat the underlying pathology and not only provide a symptomatic treatment of the injuries. Discussion: In the setting of RAS, it is advisable to perform an analysis that includes a blood count, folic acid, iron and vitamin B12, to rule out possible systemic causes and eventually treat them. Clinical management aims to improve patient function and quality of life through topical and systemic therapies; however, it is essential to identify and control the causal factors that contribute; as well as, the exclusion or treatment of the underlying systemic disease.

Defining the plasma folate concentration associated with the red blood cell folate concentration threshold for optimal neural tube defects prevention: a population-based, randomized trial of folic acid supplementation.

BACKGROUND: For women of reproductive age, a population-level red blood cell (RBC) folate concentration below the threshold 906 nmol/L or 400 ng/mL indicates folate insufficiency and suboptimal neural tube defect (NTD) prevention. A corresponding population plasma/serum folate concentration threshold for optimal NTD prevention has not been established. OBJECTIVE: The aim of this study was to examine the association between plasma and RBC folate concentrations and estimated a population plasma folate insufficiency threshold (pf-IT) corresponding to the RBC folate insufficiency threshold (RBCf-IT) of 906 nmol/L. METHODS: We analyzed data on women of reproductive age (n = 1673) who participated in a population-based, randomized folic acid supplementation trial in northern China. Of these women, 565 women with anemia and/or vitamin B-12 deficiency were ineligible for folic acid intervention (nonintervention group); the other 1108 received folic acid supplementation for 6 mo (intervention group). We developed a Bayesian linear model to estimate the pf-IT corresponding to RBCf-IT by time from supplementation initiation, folic acid dosage, methyltetrahydrofolate reductase (MTHFR) genotype, body mass index (BMI), vitamin B-12 status, or anemia status. RESULTS: Using plasma and RBC folate concentrations of the intervention group, the estimated median pf-IT was 25.5 nmol/L (95% credible interval: 24.6, 26.4). The median pf-ITs were similar between the baseline and postsupplementation samples (25.7 compared with 25.2 nmol/L) but differed moderately (±3-4 nmol/L) by MTHFR genotype and BMI. Using the full population-based baseline sample (intervention and nonintervention), the median pf-IT was higher for women with vitamin B-12 deficiency (34.6 nmol/L) and marginal deficiency (29.8 nmol/L) compared with the sufficient group (25.6 nmol/L). CONCLUSIONS: The relation between RBC and plasma folate concentrations was modified by BMI and genotype and substantially by low plasma vitamin B-12. This suggests that the threshold of 25.5 nmol/L for optimal NTD prevention may be appropriate in populations with similar characteristics, but it should not be used in vitamin B-12 insufficient populations. This trial was registered at clinicaltrials.gov as NCT00207558.

Cerebral folate deficiency: Analytical tests and differential diagnosis.

Cerebral folate deficiency is typically defined as a deficiency of the major folate species 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) in the presence of normal peripheral total folate levels. However, it should be noted that cerebral folate deficiency is also often used to describe conditions where CSF 5-MTHF is low, in the presence of low or undefined peripheral folate levels. Known defects of folate transport are deficiency of the proton coupled folate transporter, associated with systemic as well as cerebral folate deficiency, and deficiency of the folate receptor alpha, leading to an isolated cerebral folate deficiency associated with intractable seizures, developmental delay and/or regression, progressive ataxia and choreoathetoid movement disorders. Inborn errors of folate metabolism include deficiencies of the enzymes methylenetetrahydrofolate reductase, dihydrofolate reductase and 5,10-methenyltetrahydrofolate synthetase. Cerebral folate deficiency is potentially a treatable condition and so prompt recognition of these inborn errors and initiation of appropriate therapy is of paramount importance. Secondary cerebral folate deficiency may be observed in other inherited metabolic diseases, including disorders of the mitochondrial oxidative phosphorylation system, serine deficiency, and pyridoxine dependent epilepsy. Other secondary causes of cerebral folate deficiency include the effects of drugs, immune response activation, toxic insults and oxidative stress. This review describes the absorption, transport and metabolism of folate within the body; analytical methods to measure folate species in blood, plasma and CSF; inherited and acquired causes of cerebral folate deficiency; and possible treatment options in those patients found to have cerebral folate deficiency.

Can folate replacement induce lymphoma progression?

A 43-year-old Japanese man with a low haemoglobin level of 1.3 g/dL and multiorgan dysfunction syndrome (MODS) was admitted to our hospital. He was diagnosed with folate deficiency, which was initially attributed to his malnutrition. He was transfused with several units of packed red blood cells and treated with folate, thiamine and vitamin B12 supplements; he showed a prompt haematological response and recovery from MODS. However, 3 weeks after the initial recovery, he had a relapse of pancytopenia and developed high-grade fever along with rapidly enlarging, generalised lymphadenopathy. Bone marrow biopsy revealed hemophagocytosis, and lymph node biopsy revealed peripheral T-cell lymphoma, not otherwise specified. Folate supplementation may have promoted lymphoma progression.

Acid folic and pregnancy: A mandatory supplementation.

Neural tube defects (NTD) occur in 0.5 to 2 per 1000 pregnancies with various handicaps for the affected child. It is now well established that folic acid deficiency (absolute or relative) is a predisposing factor to this type of malformation. Several randomized controlled trials showed that high-dose folic acid (4mg) is an essential factor for prevention of neural tube defects recurrence and significantly prevents the first occurrence of neural tube defects with a lower dose (0.4mg). Other etiologies can favor the occurrence of NTD such as MTHFR polymorphism, some antiepileptic therapies, obesity and pregestational mellitus diabetes. Necessity of a preconception folic acid supplementation or at least folate nutritional status evaluation should be known for all of us including patients and public.

Folic acid is necessary for proliferation and differentiation of C2C12 myoblasts.

Folic acid, a water soluble B vitamin, plays an important role in cellular metabolic activities, such as functioning as a cofactor in one-carbon metabolism for DNA and RNA synthesis as well as nucleotide and amino acid biosynthesis in the body. A lack of dietary folic acid can lead to folic acid deficiency and result in several health problems, including macrocytic anemia, elevated plasma homocysteine, cardiovascular disease, birth defects, carcinogenesis, muscle weakness, and walking difficulty. However, the effect of folic acid deficiency on skeletal muscle development and its molecular mechanisms are unknown. We, therefore, investigated the effect of folic acid deficiency on myogenesis in skeletal muscle cells and found that folic acid deficiency induced proliferation inhibition and cell cycle breaking as well as cellular senescence in C2C12 myoblasts, implying that folic acid deficiency influences skeletal muscle development. Folic acid deficiency also inhibited differentiation of C2C12 myoblasts and induced deregulation of the cell cycle exit and many cell cycle regulatory genes. It inhibited expression of muscle-specific marker MyHC as well as myogenic regulatory factor (myogenin). Moreover, immunocytochemistry and Western blot analyses revealed that DNA damage was more increased in folic acid-deficient medium-treated differentiating C2C12 cells. Furthermore, we found that folic acid resupplementation reverses the effect on the cell cycle and senescence in folic acid-deficient C2C12 myoblasts but does not reverse the differentiation of C2C12 cells. Altogether, the study results suggest that folic acid is necessary for normal development of skeletal muscle cells.

Megaloblastic Anemias: Nutritional and Other Causes.

Vitamin B12 and folate deficiencies are major causes of megaloblastic anemia. Causes of B12 deficiency include pernicious anemia, gastric surgery, intestinal disorders, dietary deficiency, and inherited disorders of B12 transport or absorption. The prevalence of folate deficiency has decreased because of folate fortification, but deficiency still occurs from malabsorption and increased demand. Other causes include drugs and inborn metabolic errors. Clinical features of megaloblastic anemia include anemia, cytopenias, jaundice, and megaloblastic marrow morphology. Neurologic symptoms occur in B12 deficiency, but not in folate deficiency. Management includes identifying any deficiency, establishing its cause, and replenishing B12 or folate parenterally or orally.