Folate Deficiency
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Folate Deficiency
Folate deficiency is a nutritional and metabolic condition caused by inadequate availability of folate, also known as vitamin B9. Folate is required for one-carbon metabolism, nucleotide synthesis, DNA production and repair, methylation reactions, amino-acid metabolism, and normal cell division. Tissues with rapid cell turnover, particularly the bone marrow and developing embryo, are especially sensitive to inadequate folate.
One of the best-known consequences of folate deficiency is megaloblastic anemia, in which impaired DNA synthesis disrupts normal red blood cell development. Folate deficiency is also important during pregnancy because insufficient folate around conception and during early embryonic development is strongly associated with neural tube defects. Population-wide food fortification and supplementation programs have therefore become major public-health strategies for preventing folate-related disease.
Folate status is influenced by diet, intestinal absorption, alcohol consumption, medications, pregnancy, chronic disease, genetic variation, surgery, and other physiological conditions. Although mandatory food fortification has greatly reduced severe deficiency in some countries, clinically important deficiency and folate insufficiency continue to occur in vulnerable populations.
Biological Role of Folate
Folate participates in a network of biochemical reactions known as one-carbon metabolism. These reactions transfer single-carbon units that are required for synthesizing purines and thymidylate, compounds necessary for DNA production. Folate is also involved in the conversion of homocysteine to methionine and contributes indirectly to methylation reactions that regulate DNA, proteins, neurotransmitters, and other molecules.
When folate becomes deficient, DNA synthesis can become impaired. Rapidly dividing cells are particularly affected, explaining why folate deficiency commonly causes abnormalities in blood formation and can interfere with fetal development.
Experimental and clinical studies have also linked inadequate folate to increased incorporation of uracil into DNA, chromosome breakage, altered DNA methylation, and genomic instability. These mechanisms have generated interest in possible relationships between folate status and cancer, aging, neurological disease, and other chronic conditions.
Folate metabolism is closely connected with vitamin B12 metabolism. Vitamin B12 deficiency can impair the recycling of folate into biologically useful forms, a phenomenon often described through the methylfolate trap. Because folic acid can improve some hematological abnormalities caused by vitamin B12 deficiency without correcting neurological injury, clinicians generally consider vitamin B12 status when evaluating or treating megaloblastic anemia.
Causes and Risk Factors
Folate deficiency can result from inadequate intake, reduced absorption, increased physiological requirements, increased losses, or interference with folate metabolism.
Poor dietary intake may contribute to deficiency, particularly when diets contain few folate-rich foods or when malnutrition is present. Chronic heavy alcohol use is another established risk factor. Alcohol may reduce dietary intake while also interfering with intestinal folate absorption, hepatic storage, metabolism, and normal one-carbon pathways.
Malabsorptive gastrointestinal disorders can reduce folate availability. Studies have documented reduced folate status in conditions including celiac disease and inflammatory bowel disease. Surgical procedures that alter the gastrointestinal tract, particularly bariatric procedures such as Roux-en-Y gastric bypass and sleeve gastrectomy, can also contribute to micronutrient deficiencies and require long-term nutritional monitoring.
Pregnancy increases folate requirements because of rapid maternal and fetal cell division. Infants, children, and people with disorders involving rapid red blood cell destruction may also have increased requirements.
Kidney disease and dialysis can alter vitamin concentrations and may cause folate losses, although research has questioned whether all dialysis patients require routine supplementation.
Older adults may be vulnerable because of inadequate diets, chronic illness, medication use, malabsorption, and coexisting vitamin B12 deficiency.
Medication-Related Folate Deficiency
Several medications can interfere with folate absorption or metabolism.
Methotrexate acts partly through interference with folate-dependent metabolic pathways and is used in conditions including rheumatoid arthritis and psoriasis. Folate or folinic acid supplementation can reduce some gastrointestinal, hepatic, mucosal, and hematological adverse effects of low-dose methotrexate therapy.
Certain antiepileptic medications, especially phenytoin, have repeatedly been associated with lower folate concentrations. The relationship is clinically important because folic acid supplementation can also affect phenytoin concentrations and potentially influence seizure control.
Other drugs known to interfere with folate pathways include trimethoprim, pyrimethamine, triamterene, and additional antifolate or anticonvulsant agents.
Medication-associated deficiency therefore needs to be considered in the context of both the underlying disease and possible drug-supplement interactions.
Folate-Deficiency Anemia
A major clinical manifestation of folate deficiency is megaloblastic anemia.
Folate is required for normal DNA synthesis in developing red blood cells. When folate is insufficient, nuclear maturation is delayed while cellular growth continues, producing abnormally large precursor cells and macrocytic red blood cells.
Symptoms can include fatigue, weakness, reduced exercise tolerance, pallor, shortness of breath, and other manifestations associated with anemia. Changes involving the mouth and tongue may also occur.
Laboratory evaluation commonly includes a complete blood count and measurements of folate and vitamin B12 status. Serum folate reflects relatively recent intake, while red blood cell folate has historically been used as an indicator of longer-term folate status. Research has questioned whether routine red-cell folate measurement adds sufficient diagnostic value in all clinical circumstances, particularly in countries where food fortification has made severe folate deficiency less common.
Homocysteine may rise in both folate and vitamin B12 deficiency. Methylmalonic acid is more specifically associated with vitamin B12 deficiency and can therefore help distinguish between the two conditions.
Pregnancy and Neural Tube Defects
Folate has a particularly important role before conception and during the earliest stages of pregnancy.
The embryonic neural tube develops and closes very early in pregnancy. Inadequate folate status during this period increases the risk of neural tube defects, including spina bifida and anencephaly.
Evidence from clinical studies, population surveillance, systematic reviews, and fortification programs has consistently supported folic acid intake before conception and during early pregnancy as an effective strategy for reducing neural tube defects.
Because neural tube closure occurs before many people know they are pregnant, public-health recommendations generally emphasize adequate folic acid intake among people who could become pregnant rather than waiting until pregnancy has been confirmed.
Research has also explored associations between folate deficiency and other reproductive outcomes, including impaired fetal growth, placental complications, pre-eclampsia, miscarriage, and neurodevelopment. Evidence for these additional outcomes varies, and the neural tube defect relationship remains among the clearest and most important established consequences of inadequate maternal folate.
Food Fortification and Prevention
Mandatory folic acid fortification has become one of the major population-level approaches to preventing folate deficiency and neural tube defects.
Countries including the United States, Canada, Australia, Chile, and others have introduced folic acid fortification of commonly consumed grain products. Studies conducted after fortification have documented substantial increases in population folate concentrations and large reductions in the prevalence of biochemical folate deficiency.
Population studies have also reported reductions in neural tube defects following mandatory fortification. Research from the United States and Canada found measurable declines after fortification policies were implemented, while international systematic reviews have found substantially lower rates of folate-sensitive neural tube defects in regions with mandatory fortification.
Despite these successes, global coverage remains incomplete. Many preventable cases of spina bifida and anencephaly continue to occur in countries without effective fortification programs or where women enter pregnancy with inadequate folate stores.
Fortification complements rather than entirely replaces dietary improvement and targeted supplementation. Women capable of becoming pregnant may still be advised to take folic acid because achieving protective folate status before conception is particularly important.
Population Patterns and Vulnerable Groups
The prevalence of folate deficiency varies greatly between countries and populations.
Food fortification has made severe deficiency relatively uncommon in some high-income countries. U.S. population studies, for example, have documented large increases in blood folate concentrations after fortification and a major decline in folate-deficiency anemia.
Deficiency nevertheless persists among selected populations. Studies have identified folate inadequacy among pregnant women in several African and Asian settings, children with poor micronutrient intake, people experiencing malnutrition, and some economically disadvantaged populations even in countries with mandatory fortification.
Pregnant women are especially important because folate requirements rise while the consequences of inadequate status extend to the developing fetus.
People with alcohol use disorders, gastrointestinal disease, bariatric surgery, chronic hemolytic disease, renal disease, restrictive diets, or medications that interfere with folate metabolism may require particular attention.
Folate, Vitamin B12, and Neurological Health
Folate and vitamin B12 metabolism are closely interconnected, making simultaneous assessment important in some patients.
Large doses of folic acid can correct the megaloblastic anemia caused by vitamin B12 deficiency while leaving the underlying neurological disorder untreated. This historical concern is sometimes described as the masking of vitamin B12 deficiency.
Folate deficiency itself has also been associated with neurological and psychiatric abnormalities. Research has examined relationships between low folate and depression, cognitive impairment, dementia, schizophrenia, bipolar disorder, and other neuropsychiatric conditions.
Observational studies frequently find lower folate concentrations among some people with psychiatric or cognitive disorders, but associations do not necessarily establish that folate deficiency is the primary cause of those conditions. Age, diet, medications, chronic disease, socioeconomic factors, vitamin B12 status, and homocysteine may all influence the observed relationships.
In older adults, identifying vitamin B12 deficiency is particularly important because both deficiencies can coexist.
Folate and Homocysteine
Folate is required for the remethylation of homocysteine to methionine. When folate is deficient, blood homocysteine concentrations can rise.
Elevated homocysteine has been associated with cardiovascular and cerebrovascular disease in epidemiological research. Folic acid supplementation reliably lowers homocysteine in many individuals, particularly when baseline concentrations are elevated.
Whether lowering homocysteine consistently produces corresponding reductions in cardiovascular events has been more complicated. The biological relationship is well established, but clinical outcomes depend on population characteristics, baseline folate status, vitamin B12 status, kidney function, fortification exposure, and other cardiovascular risk factors.
Genetic Variation and Folate Metabolism
Genetic differences can influence folate metabolism and folate requirements.
One of the most extensively studied variants occurs in the MTHFR gene. The common C677T variant reduces activity of the methylenetetrahydrofolate reductase enzyme. Individuals with the 677TT genotype often have lower folate concentrations and higher homocysteine concentrations, particularly when dietary folate intake is inadequate.
Research indicates that folate intake and genetic variation interact rather than acting independently. Adequate folate status can reduce some of the metabolic effects associated with MTHFR variants.
Other genetic variants affecting folate transport and metabolism can also modify folate concentrations, homocysteine, and responses to supplementation.
DNA Damage, Genome Stability, and Cancer
Folate's role in nucleotide synthesis and methylation has prompted extensive investigation into its relationship with cancer.
Severe folate deficiency can disrupt DNA synthesis, increase uracil incorporation into DNA, contribute to chromosome breakage, and alter methylation patterns. These biological mechanisms provide plausible pathways through which inadequate folate might contribute to carcinogenesis.
Observational research has associated low folate status with increased risk of several cancers, although relationships differ by cancer type, dietary environment, genetic background, and level of folate exposure.
The relationship is complex because folate supports normal DNA repair and genomic stability but also participates in nucleotide synthesis required by rapidly dividing cells. Consequently, the effects of folate deficiency, normal folate nutrition, and unusually high folic acid exposure should not automatically be treated as equivalent.
Cerebral Folate Deficiency
Cerebral folate deficiency is a distinct neurological condition in which concentrations of 5-methyltetrahydrofolate are abnormally low in cerebrospinal fluid despite sometimes normal peripheral folate measurements.
Causes include inherited abnormalities affecting folate transport or metabolism and autoantibodies directed against folate receptor alpha. These abnormalities may interfere with transport of folate into the central nervous system.
Affected children can develop neurological and developmental abnormalities. Research has identified folate-receptor-blocking autoantibodies in some patients and reported improvement in selected cases following treatment with folinic acid.
Cerebral folate deficiency differs from ordinary dietary folate deficiency and requires specialized diagnostic evaluation.
Diagnosis
Diagnosis begins with clinical history, dietary assessment, medication review, and laboratory investigation.
Potential contributing factors include inadequate diet, pregnancy, heavy alcohol consumption, malabsorptive disorders, gastrointestinal surgery, chronic disease, medications, and increased physiological requirements.
Blood tests may include complete blood count, serum folate, vitamin B12, homocysteine, and, when clinically appropriate, methylmalonic acid. Red-cell folate can also be measured, although its routine diagnostic value has been debated.
The distinction between folate deficiency and vitamin B12 deficiency is particularly important because both can produce megaloblastic anemia while vitamin B12 deficiency carries the additional risk of potentially serious neurological injury.
Clinicians therefore generally investigate the underlying cause rather than treating an abnormal folate result in isolation.
Treatment and Prevention
Treatment usually involves correcting the cause of deficiency while restoring adequate folate availability.
Folic acid supplementation is commonly used for dietary deficiency and folate-deficiency anemia. Dietary improvement can provide additional folate through foods naturally rich in the vitamin and through fortified foods.
When malabsorption, medication use, alcohol consumption, bariatric surgery, or chronic illness contributes to deficiency, the underlying factor may also require management.
Vitamin B12 status should be considered before or during treatment when megaloblastic anemia is present because folic acid alone does not correct the neurological effects of vitamin B12 deficiency.
Population prevention relies on several complementary strategies: adequate diets, folic acid supplementation around conception, food fortification, identification of high-risk groups, and appropriate clinical monitoring.
Conclusion
Folate deficiency illustrates how a single micronutrient can influence processes ranging from blood formation and fetal development to DNA synthesis, methylation, homocysteine metabolism, and neurological function.
Its most clearly established clinical consequences include megaloblastic anemia and increased risk of neural tube defects when folate status is inadequate around conception. Deficiency can arise through poor intake, malabsorption, alcohol use, increased physiological requirements, medications, surgery, chronic disease, or interactions with genetic and metabolic factors.
Mandatory food fortification has dramatically reduced biochemical folate deficiency and neural tube defects in many populations, demonstrating the effectiveness of population-level prevention. Nevertheless, deficiency remains relevant among pregnant women, people with malabsorption or restrictive diets, individuals using folate-interfering medications, people with alcohol-related disease, and other vulnerable groups.
Effective prevention and treatment depend not merely on providing folic acid but on identifying why folate status is inadequate and recognizing its close metabolic relationship with vitamin B12. Together, dietary improvement, supplementation when appropriate, food fortification, clinical assessment, and population surveillance have made folate deficiency one of the most preventable micronutrient-related health problems.
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Clinical Overviews and Diagnosis
1. | Larry E. Johnson | Merck Manual Professional Edition | 2026
Reviews inadequate intake, malabsorption, medication-related deficiency, megaloblastic anemia, diagnosis, and oral folate treatment, with attention to pregnancy and neural tube defects.
2. | MedlinePlus Medical Encyclopedia | U.S. National Library of Medicine | 2026
Focuses on folate-deficiency anemia, describing macrocytic and megaloblastic red blood cells, common risk factors, symptoms, blood testing, dietary measures, and folic acid therapy.
3. | Sujatha Baddam, Kashif M. Khan, Ishwarlal Jialal | StatPearls / NCBI Bookshelf | 2025
Provides a broad clinical review of folate deficiency, including causes, symptoms, laboratory testing, differential diagnosis, treatment, pregnancy risks, and the importance of excluding vitamin B12 deficiency before treatment.
4. | MedlinePlus Medical Encyclopedia | U.S. National Library of Medicine | 2025
Explains common causes of low folate, including poor diet, alcohol use, malabsorption, dialysis, and medications, along with symptoms, testing, treatment, and complications.
5. | Cleveland Clinic | Cleveland Clinic | 2025
Describes how vitamin B9 deficiency interferes with red blood cell production and explains symptoms, underlying conditions, diagnosis, supplementation, and expected recovery.
6. | Mayo Clinic Staff | Mayo Clinic | 2025
Summarizes folate functions, dietary sources, recommended intake, folate deficiency, malabsorption, pregnancy needs, supplementation, and interactions.
7. | Office of Dietary Supplements | National Institutes of Health | 2022
Gives an evidence-based professional overview of folate physiology, dietary requirements, biomarkers, deficiency, at-risk groups, health effects, fortification, supplementation, and safety.
8. | Office of Dietary Supplements | National Institutes of Health | 2022
Explains folate needs, food and supplement sources, groups at risk of inadequate intake, megaloblastic anemia, pregnancy risks, and health effects in accessible language.
9. | Cleveland Clinic | Cleveland Clinic | 2021
Provides a patient-oriented overview of folate deficiency, including food sources, causes, symptoms, pregnancy complications, prevention, and treatment.
10. | Multiple authors | International Journal of Environmental Research and Public Health | 2020
Examines folate, vitamin B12, and iron deficiencies among patients presenting with burning mouth, angular cheilitis, recurrent aphthous ulcers, tongue changes, and mucosal erythema.
11. | NHS | National Health Service | n.d.
Reviews vitamin B12 and folate deficiency anemia, including fatigue, mouth and tongue changes, neurological and psychological symptoms, causes, diagnostic tests, and treatment.
Laboratory Assessment, Biomarkers, and Folate Metabolism
1. | Mary Torrez et al. | International Journal of Laboratory Hematology | 2022
Reviews acquired megaloblastic anemia with emphasis on blood and bone-marrow findings, folate and B12 pathways, and practical laboratory investigation.
2. | Multiple authors | Journal of Nutrition | 2015
Comprehensive Biomarkers of Nutrition for Development review covers serum folate, red-cell folate, homocysteine, biology, interpretation, and research needs.
3. | Edward De Bruyn, Béatrice Gulbis, Frédéric Cotton | European Journal of Haematology | 2014
Examines more than 60,000 serum folate results and proposes practical decision limits while questioning the added value of routine red-cell folate testing.
4. | World Health Organization | WHO | 2014
Provides population-level guidance on using serum, plasma, and red blood cell folate concentrations to define folate status and monitor public-health interventions.
5. | Multiple authors | Clinical Biochemistry | 2014
Questions routine serum and red-cell folate testing in fortified populations where clinically significant deficiency has become uncommon.
Evaluates whether red-cell folate testing offers meaningful advantages over serum folate for routine diagnosis and discusses the strengths and limitations of each marker.
7. | Jin Young Park et al. | Molecular Nutrition & Food Research | 2013
Reviews validation studies comparing estimates of dietary folate intake with serum, plasma, and red-cell biomarkers.
8. | Multiple authors | American Journal of Clinical Nutrition | 2011
Summarizes expert discussions about folate biomarkers and analytical methods used in U.S. NHANES surveys.
9. | Multiple authors | American Journal of Clinical Nutrition | 2011
Reviews measurement-method issues surrounding NHANES monitoring of folate and vitamin B12 biomarkers.
10. | Multiple authors | American Journal of Clinical Nutrition | 2011
Traces the history of folate and vitamin B12 biomarker measurements in NHANES and their use for population surveillance.
11. | Multiple authors | American Journal of Clinical Nutrition | 2011
Reviews the historical evolution, strengths, and limitations of methods used to measure folate status.
12. | S. N. Wickramasinghe | Blood Reviews | 2006
Discusses the causes and diagnosis of megaloblastic anemia and the roles and limitations of folate, vitamin B12, homocysteine, methylmalonic acid, and related tests.
13. | Multiple authors | Journal of Clinical Pathology | 1997
Compares serum and red-cell folate testing and concludes serum folate is generally the more appropriate screening assay.
14. | Multiple authors | American Journal of Medicine | 1994
Evaluates homocysteine and methylmalonic acid as sensitive metabolic markers for distinguishing clinically important folate and vitamin B12 deficiencies.
15. | William S. Beck | Annual Review of Medicine | 1991
Reviews the diagnostic approach to megaloblastic anemia, including how clinicians distinguish folate deficiency from vitamin B12 deficiency and other marrow disorders.
16. | Lynn B. Bailey | Journal of Nutrition | 1990
Classic review explains the progression of folate depletion and laboratory approaches for assessing folate nutritional status.
17. | Ralph Carmel | Western Journal of Medicine | 1978
Presents a classic laboratory framework for identifying megaloblastosis, determining whether folate or vitamin B12 deficiency is present, and investigating the underlying cause.
Genetics, One-Carbon Metabolism, and Epigenetics
1. | Selma Mahmood et al. | Nutrients | 2020
Reviews folate and vitamin B12 in one-carbon metabolism and explains how deficiency can disrupt blood formation, development, cognition, methylation, and other cellular processes.
2. | Jason W. Locasale | Cell Metabolism | 2016
Reviews one-carbon metabolism, explaining how folate supports nucleotide synthesis, amino-acid homeostasis, epigenetic regulation, redox defense, and cellular physiology.
3. | Multiple authors | European Journal of Nutrition | 2016
Meta-analysis shows MTHFR 677TT is associated with lower folate and higher homocysteine and influences response to folic acid supplementation.
4. | Multiple authors | Journal of Nutrition | 2015
Shows that combinations of polymorphisms in folate transport and metabolism genes modify folate status and homocysteine concentrations.
5. | Krista S. Crider, Thomas P. Yang, Robert J. Berry, Lynn B. Bailey | Advances in Nutrition | 2012
Explains folate's role in DNA methylation and reviews evidence connecting folate status with epigenetic regulation, development, and chronic disease.
6. | Multiple authors | Journal of Nutrition | 2005
Controlled dietary study examines homocysteine metabolism during folate restriction in young women with different MTHFR C677T genotypes.
7. | Multiple authors | Clinical Chemistry and Laboratory Medicine | 2004
Studies MTHFR variants in a mildly folate-deficient population and finds genotype modifies the relationship between folate and homocysteine.
8. | Multiple authors | PubMed-indexed genetics study | 2001
Case-control research links low maternal folate status and MTHFR 677TT genotype with increased risk of severe neural tube defects.
9. | Multiple authors | PubMed-indexed metabolic study | 1998
Investigates how folate deficiency and MTHFR genotype interact to influence enzyme activity, folate forms, and homocysteine.
10. | Multiple authors | Circulation | 1996
Demonstrates interaction between folate status and the common MTHFR C677T variant in determining plasma homocysteine concentrations.
Pregnancy, Reproductive Health, and Neural Tube Defects
1. | Samantha Yoo et al. | Journal of Global Health | 2026
Synthesizes systematic-review evidence on folate, megaloblastic anemia, and neural tube defects and frames folate deficiency as a global life-course health issue.
2. | Multiple authors | PubMed-indexed maternal nutrition study | 2026
Reports a high burden of red-cell folate deficiency among first-trimester pregnant women in the neural-tube-defect high-risk Tigray region of Ethiopia.
3. | Biruk Beletew Abate et al. | Annals of Nutrition and Metabolism | 2025
Umbrella review combining systematic reviews and meta-analyses on preconception folic acid or multivitamin use and the prevention of neural tube defects.
4. | Multiple authors | Reproductive Toxicology | 2024
Reviews folate in DNA stability, epigenetics, one-carbon metabolism, and neural tube development, emphasizing risks associated with inadequate folate status around conception.
5. | Meera Viswanathan et al. | JAMA | 2023
Updates the evidence base for folic acid supplementation to prevent neural tube defects and examines benefits and potential harms across large observational datasets.
6. | Xue-Yun Qin et al. | Nutrients | 2023
Reviews folate metabolism and folate-receptor autoantibodies in early pregnancy, with particular attention to miscarriage.
7. | Multiple authors | Nutrients | 2022
Reviews clinical and experimental evidence that maternal folate deficiency may affect offspring brain structure, neurogenesis, memory, motor function, language, and psychological outcomes.
8. | Multiple authors | PubMed-indexed maternal nutrition study | 2022
Evaluates red-cell folate and factors associated with folate insufficiency among first-trimester pregnant women in Addis Ababa.
9. | Prajkta Bhide, Anita Kar | European Journal of Clinical Nutrition | 2019
Measures folate deficiency and associated determinants among urban Indian women during the periconception period.
10. | Colleen G. Williams et al. | Nutrition Reviews | 2015
Reviews possible links between folate deficiency, disrupted methylation, elevated homocysteine, genomic instability, and biological pathways involved in pre-eclampsia.
11. | World Health Organization | WHO | 2015
Establishes population-level serum and red blood cell folate targets for women of reproductive age to guide neural tube defect prevention programs.
12. | Edward A. Yetley et al. | Food and Nutrition Bulletin | 2008
Reviews effects of folate and vitamin B12 deficiency during pregnancy on fetal growth, birth weight, neural tube defects, infant development, and childhood outcomes.
13. | Multiple authors | American Journal of Clinical Nutrition | 2001
Zimbabwean study finds HIV infection and low serum folate among factors associated with reduced hemoglobin during pregnancy.
14. | Joel G. Ray, Philip R. Wyatt, David E. C. Cole | Placenta | 1999
Systematic review examining folate deficiency, hyperhomocysteinemia, placental abruption, pre-eclampsia, and spontaneous pregnancy loss.
15. | Sean Daly et al. | The Lancet | 1997
Uses red-cell folate response to different folic acid doses to estimate the amount needed to achieve folate concentrations associated with lower neural tube defect risk.
Fortification and Population Prevention
1. | Centers for Disease Control and Prevention | CDC | 2026
Explains why folic acid is needed for new-cell formation and why adequate intake before and during early pregnancy is central to neural tube defect prevention.
2. | Centers for Disease Control and Prevention | CDC | 2026
Provides clinicians with current guidance on folic acid, food and supplement sources, recommended intake, and counseling for people who could become pregnant.
3. | Multiple authors | American Journal of Clinical Nutrition | 2026
Systematic review and meta-analysis showing that mandatory grain fortification generally raises folate concentrations and reduces population folate deficiency and insufficiency.
4. | Sisay Moges, Kehabtimer Shiferaw Kotiso, Mesfin Menza Jaldo | BMC Nutrition | 2026
Meta-analysis finds mandatory folic acid fortification associated with a substantial reduction in neural tube defects compared with pre-fortification periods.
5. | Multiple authors | Birth Defects Research | 2026
Updates worldwide estimates of folic-acid-preventable spina bifida and anencephaly prevented through grain fortification policies in 2024.
6. | Matthew Quinn et al. | eClinicalMedicine | 2024
Systematic review compares international folic acid fortification policies with population folate levels, neural tube defects, and stroke mortality.
7. | U.S. Preventive Services Task Force | USPSTF | 2023
Recommends daily folic acid supplementation for people planning or capable of pregnancy and explains timing, dosage, and the evidence supporting prevention.
8. | Multiple authors | European Journal of Nutrition | 2023
Reviews global strategies for improving folate status in women of reproductive age through diet, supplements, education, and fortification.
9. | World Health Organization | WHO | 2022
Explains why food fortification is used and notes that folic-acid fortification can improve folate status and reduce neural tube defects.
10. | Multiple authors | Birth Defects Research | 2022
Reviews global prevention of folic-acid-preventable neural tube defects in 2020, thirty years after landmark prevention evidence emerged.
11. | Multiple authors | Journal of Neurosurgery: Pediatrics | 2021
Systematic review concludes mandatory fortification and supplementation policies reduce folate-sensitive neural tube defects worldwide.
12. | Multiple authors | Birth Defects Research | 2020
Provides a 2019 global assessment of folic-acid-preventable spina bifida and anencephaly and remaining prevention gaps.
13. | Callie A. M. Atta et al. | American Journal of Public Health | 2016
Global systematic review finds substantially lower spina bifida prevalence in regions with mandatory folic acid fortification.
14. | Vijaya Kancherla et al. | Birth Defects Research | 2016
Estimates the global proportion of preventable spina bifida and anencephaly cases prevented through mandatory folic acid fortification in 2015.
15. | Jennifer Williams et al. | Morbidity and Mortality Weekly Report | 2015
Estimates the number of neural tube defect-affected pregnancies prevented annually in the United States after mandatory folic acid fortification.
16. | Multiple authors | PLOS ONE | 2013
Evaluates iron and folate status among women in Uzbekistan after several years of national micronutrient flour fortification.
17. | Robert B. Brown et al. | Medical Journal of Australia | 2011
Reports marked reductions in low serum and red-cell folate following mandatory folic acid fortification of bread-making flour in Australia.
18. | Eva Hertrampf, Fanny Cortés | Food and Nutrition Bulletin | 2008
Reviews Chile's national wheat-flour fortification program and its effects on folate status and neural tube defect prevalence.
19. | Philippe De Wals et al. | New England Journal of Medicine | 2007
Canadian population study finding a large reduction in neural tube defects after nationwide folic acid food fortification.
20. | Margaret A. Honein et al. | JAMA | 2001
National U.S. study reporting a decline in neural tube defect prevalence after mandatory folic acid fortification of enriched grain products.
21. | Multiple authors | Journal of Nutrition | 2001
Framingham study demonstrates increased red-cell folate and reduced prevalence of deficient folate status after U.S. folic acid fortification.
Prevalence and Population Studies
1. | Multiple authors | BMJ Open | 2023
Community-based study in eastern Ethiopia reporting high folate deficiency among pregnant women and identifying associated dietary and demographic factors.
2. | Multiple authors | Indian Journal of Pediatrics | 2023
National analysis describing folate and vitamin B12 deficiencies among Indian preschoolers, school-age children, and adolescents, with substantial regional variation.
3. | Multiple authors | Journal of Family Medicine and Primary Care | 2022
Hospital-based study from northern India measuring folate, vitamin B12, and anemia prevalence among children 6 to 59 months old.
4. | Christine M. Pfeiffer et al. | American Journal of Clinical Nutrition | 2019
Uses NHANES data through 2016 to assess U.S. folate status two decades after fortification, including persistent insufficiency in some women and demographic groups.
5. | Multiple authors | Public Health Nutrition | 2019
Queensland laboratory data show a major reduction in folic acid deficiency after Australia introduced mandatory fortification.
6. | Lisa M. Rogers et al. | Annals of the New York Academy of Sciences | 2018
Systematic review of global folate status in women of reproductive age, finding major geographic differences and substantial insufficiency in many lower-income settings.
7. | Multiple authors | Pan African Medical Journal | 2018
Study of pregnant women at Pumwani Maternity Hospital in Kenya assessing folate deficiency, awareness, and use of folic-acid-fortified flour after mandatory fortification.
8. | Oluwaseun A. Odewole et al. | American Journal of Clinical Nutrition | 2013
Examines older U.S. adults and finds folate-deficiency anemia to be nearly eliminated in the post-fortification era.
9. | Christine M. Pfeiffer et al. | American Journal of Clinical Nutrition | 2007
Compares U.S. blood folate concentrations before and after fortification and documents the sharp post-fortification decline in low folate status.
10. | Joel G. Ray et al. | Canadian Journal of Public Health | 2002
Finds that folate insufficiency declined among Canadian adults after mandatory folic acid fortification was introduced.
Malabsorption and Gastrointestinal Disease
1. | Multiple authors | Nutrients | 2021
Reviews folate deficiency risk in inflammatory bowel disease, including malabsorption, dietary restriction, sulfasalazine exposure, anemia, bone health, and homocysteine.
2. | Multiple authors | Nutrients | 2017
Meta-analysis finding lower average serum folate concentrations in inflammatory bowel disease patients compared with controls, especially in ulcerative colitis.
3. | Multiple authors | Nutrients | 2013
Reviews common folate, iron, vitamin B12, vitamin D, zinc, and magnesium deficiencies in celiac disease and discusses when supplementation is needed.
Alcohol Use and Liver Disease
1. | Arantza Sanvisens et al. | Drug and Alcohol Dependence | 2017
Measures serum and red-cell folate in people entering treatment for alcohol use disorder and evaluates the prevalence and correlates of deficiency.
2. | M. Tiller et al. | Der Internist | 2010
Reports severe folate-deficiency anemia in a patient with chronic alcohol abuse and probable liver cirrhosis.
3. | Charles H. Halsted, Jesus A. Villanueva, Angela M. Devlin | Alcohol | 2002
Reviews interactions among folate deficiency, methionine metabolism, oxidative stress, and the development of alcoholic liver disease.
4. | Charles H. Halsted et al. | Proceedings of the National Academy of Sciences | 2002
Experimental research finds that folate deficiency amplifies ethanol-induced disturbances of methionine metabolism, DNA damage, oxidative stress, and liver injury.
Describes experimental evidence that folate deficiency can accelerate alcoholic liver injury through disrupted methionine metabolism and impaired antioxidant defenses.
6. | Charles H. Halsted et al. | Journal of Nutrition | 2002
Reviews mechanisms by which chronic alcohol exposure impairs folate absorption, metabolism, storage, and function.
7. | A. Wu, I. Chanarin, G. Slavin, A. J. Levi | British Journal of Haematology | 1975
Examines folate deficiency in people with chronic heavy alcohol consumption and its relationships with diet, macrocytosis, megaloblastic changes, liver disease, and tissue folate stores.
Bariatric Surgery and Malabsorption
1. | Multiple authors | PubMed-indexed bariatric surgery study | 2026
Reports anemia affecting nearly half of a postoperative bariatric cohort, with folate deficiency differing according to surgical procedure.
2. | Multiple authors | Obesity Surgery | 2022
Reports a high prevalence of preoperative micronutrient disorders in bariatric-surgery candidates, including frequent folate deficiency.
3. | Yeongkeun Kwon et al. | Obesity Reviews | 2022
Meta-analysis compares anemia, iron, vitamin B12, and folate deficiency after Roux-en-Y gastric bypass versus sleeve gastrectomy.
4. | Multiple authors | Obesity Surgery | 2022
Systematic review and meta-analysis examines B-complex vitamin deficiencies following Roux-en-Y gastric bypass and sleeve gastrectomy.
5. | Multiple authors | Obesity Surgery | 2020
Systematic review of iron, vitamin B12, folate, and copper deficiency after bariatric surgery and the evidence linking these deficiencies to anemia.
6. | Multiple authors | Surgery for Obesity and Related Diseases | 2014
Compares long-term micronutrient deficiencies after sleeve gastrectomy and Roux-en-Y gastric bypass, including substantial folate deficiency in both groups.
7. | Multiple authors | Obesity Surgery | 2014
Finds folate deficiency common before sleeve gastrectomy and tracks changes in micronutrient status during postoperative follow-up.
8. | G. N. Mallory, A. M. Macgregor | Obesity Surgery | 1991
Examines folate status before and after gastric bypass and suggests that deficiency becomes uncommon when patients consistently use recommended multivitamin supplements.
Medication-Related Folate Depletion and Supplementation
1. | Lijun Liu et al. | Clinical Rheumatology | 2019
Systematic review finding that folate supplementation can reduce methotrexate-related liver enzyme abnormalities, gastrointestinal side effects, and treatment withdrawal.
2. | Beverley Shea et al. | Journal of Rheumatology | 2014
Systematic review of randomized trials assessing folic or folinic acid for reducing gastrointestinal, hepatic, mucosal, and hematologic toxicity from low-dose methotrexate.
3. | Multiple authors | Annals of Neurology | 2011
Large prospective study finds several antiepileptic drugs associated with reduced serum folate or increased frequency of low folate concentrations.
4. | Multiple authors | Seizure | 2006
Compares common antiepileptic drugs and reports significantly reduced folic acid concentrations in patients receiving phenytoin.
5. | Multiple authors | Journal of Clinical Psychopharmacology | 2005
Reports lower folate and higher homocysteine concentrations among epilepsy patients experiencing interictal schizophrenia-like psychosis.
6. | Multiple authors | Journal of Rheumatology | 2005
Shows methotrexate can reduce red-cell folate and increase homocysteine while low-dose folic acid supplementation limits these effects.
7. | S. L. Whittle, R. A. Hughes | Rheumatology | 2004
Reviews folate supplementation during methotrexate treatment for rheumatoid arthritis and its role in reducing gastrointestinal and hepatic adverse effects.
8. | Multiple authors | Scandinavian Journal of Rheumatology | 2001
Reviews folate supplementation during methotrexate therapy and proposes practical approaches for balancing toxicity reduction with preservation of drug efficacy.
9. | Multiple authors | Epilepsy Research | 2000
Evaluates homocysteine and B-vitamin status during antiepileptic monotherapy and finds particularly low plasma folate among many phenytoin-treated patients.
10. | Multiple authors | Annals of Pharmacotherapy | 1995
Reviews evidence that phenytoin lowers serum folate and that folic acid replacement can change phenytoin pharmacokinetics and seizure control.
11. | Multiple authors | PubMed-indexed rheumatology study | 1995
Finds lower folate concentrations among rheumatoid and psoriatic arthritis patients receiving low-dose methotrexate than among untreated controls.
12. | C. M. Casserly, K. C. Stange, M. M. Chren | Journal of the American Academy of Dermatology | 1993
Describes severe megaloblastic anemia attributed to methotrexate-induced folate deficiency during long-term low-dose treatment for psoriasis.
13. | A. Iwama et al. | Internal Medicine | 1992
Reports megaloblastic anemia associated with psoriasis and folate deficiency and discusses possible contributions from previous methotrexate therapy.
14. | Multiple authors | British Journal of Nutrition | 1988
Compares red-cell folate in epilepsy patients receiving carbamazepine, phenytoin, valproate, or multiple anticonvulsants and evaluates dietary folate intake.
15. | M. J. Berg et al. | Therapeutic Drug Monitoring | 1987
Examines folic acid supplementation in folate-deficient patients receiving phenytoin and documents significant changes in serum phenytoin concentrations.
16. | D. G. Lambie, R. H. Johnson | Drugs | 1985
Reviews drugs that interfere with folate metabolism, including methotrexate, pyrimethamine, trimethoprim, triamterene, anticonvulsants, and other agents.
17. | Multiple authors | Journal of Neurology, Neurosurgery & Psychiatry | 1985
Links antiepileptic therapy with lower folate status and examines associations among folate deficiency, macrocytosis, polytherapy, depression, and psychiatric morbidity.
18. | M. P. Rivey, D. D. Schottelius, M. J. Berg | Drug Intelligence and Clinical Pharmacy | 1984
Reviews the two-way interaction between phenytoin and folate, including folate depletion during chronic treatment and altered phenytoin concentrations after supplementation.
19. | L. Fry et al. | British Journal of Dermatology | 1971
Investigates mechanisms contributing to folate deficiency in people with psoriasis.
Nutrition, Diet, and Malnutrition
1. | Multiple authors | British Journal of Nutrition | 2022
Assesses folate and vitamin B12 status in Norwegian vegans and vegetarians and finds folate deficiency uncommon despite concern about other B vitamins.
2. | Multiple authors | Journal of General Internal Medicine | 2021
Finds clinically meaningful folate deficiency in an urban safety-net population despite mandatory U.S. food fortification.
3. | Multiple authors | Public Health Nutrition | 2021
Reports high micronutrient inadequacy among South Indian schoolchildren, including substantial folate deficiency.
4. | Multiple authors | PubMed-indexed nutrition study | 2002
Compares B-vitamin status and homocysteine in vegan, vegetarian, semivegetarian, and conventional diets.
5. | D. J. Eedy, J. G. Curran, W. J. Andrews | Postgraduate Medical Journal | 1986
Case report describes profound folate deficiency in a young woman with bulimia nervosa.
6. | J. D. Green | Southern Medical Journal | 1975
Reports megaloblastic anemia from folate deficiency in a vegetarian using long-term oral contraceptives.
Infants, Children, and Hemolytic Disorders
1. | Multiple authors | American Journal of Clinical Nutrition | 2025
Randomized crossover trial evaluates whether children with sickle cell disease continue to benefit from daily folic acid in the fortification era.
2. | Multiple authors | PubMed-indexed hematology study | 2019
Finds extremely high serum folate concentrations in many sickle cell and thalassemia patients receiving routine folic acid supplementation.
3. | R. Dixit et al. | Cochrane Database of Systematic Reviews | 2018
Updated review finds supplementation raises serum folate in sickle cell disease but clinical benefits remain uncertain.
4. | Multiple authors | Cochrane Database of Systematic Reviews | 2016
Reviews evidence for routine folic acid supplementation in sickle cell disease and identifies major limitations in the available trials.
5. | Multiple authors | Public Health Nutrition | 2012
Systematic review evaluates folate supplementation and folate status in infants, children, and adolescents, including low-birth-weight infants.
6. | M. K. Strelling, D. G. Blackledge, H. B. Goodall | Archives of Disease in Childhood | 1979
Examines diagnosis and treatment of folate deficiency in low-birth-weight and preterm infants.
7. | Multiple authors | PubMed-indexed hematology study | 1975
Investigates folate deficiency in sickle cell anemia and emphasizes increased folate requirements associated with chronic hemolysis.
Renal Disease and Dialysis
1. | Multiple authors | PubMed-indexed nephrology study | 2008
Measures folate and other vitamin concentrations before and after hemodialysis, hemodiafiltration, and hemofiltration.
2. | Multiple authors | Nefrología | 2001
Evaluates folic acid and vitamin B6 supplementation for lowering elevated homocysteine concentrations in hemodialysis patients.
3. | Multiple authors | Nephrology Dialysis Transplantation | 2000
Evaluates true folate deficiency in hemodialysis and peritoneal dialysis patients and questions routine supplementation without appropriate folate assessment.
4. | Multiple authors | Journal of Renal Nutrition | 2000
Demonstrates significant folate losses during high-efficiency hemodialysis and examines associated hyperhomocysteinemia.
5. | Multiple authors | Clinical Nephrology | 1999
Compares serum and erythrocyte folate measurements in chronic hemodialysis and questions routine supplementation based solely on low serum folate.
6. | Multiple authors | PubMed-indexed renal nutrition study | 1986
Longitudinal study tracks plasma and red-cell B-vitamin concentrations in chronic hemodialysis patients without routine supplementation.
7. | K. E. Hemmeloff Andersen | Clinical Nephrology | 1977
Longitudinal research examines folate status and folate losses in chronic renal failure patients maintained on dialysis.
8. | Multiple authors | PubMed-indexed renal study | 1977
Examines plasma and erythrocyte folate in chronic renal failure and emphasizes red-cell folate for assessing true deficiency.
Aging, Cognition, Psychiatric Effects, and Vitamin B12 Interaction
1. | Multiple authors | American Journal of Clinical Nutrition | 2024
Reviews clinical and epidemiological evidence that high folic acid exposure may complicate vitamin B12 deficiency and discusses implications for diagnosis and treatment.
2. | Anat Rotstein et al. | Evidence-Based Mental Health | 2022
Large cohort study associating serum folate deficiency in older adults with increased subsequent risks of dementia and all-cause mortality.
3. | Multiple authors | BMC Psychiatry | 2019
Systematic review and meta-analysis finds lower serum folate concentrations in people with bipolar disorder compared with controls.
4. | James L. Mills, Anne M. Molloy, Edward H. Reynolds | BMJ | 2018
Presents opposing expert perspectives on the benefits of folic acid fortification and the potential risk of masking or worsening vitamin B12 deficiency.
5. | Multiple authors | Scientific Reports | 2018
Investigates vitamin D and folate status in schizophrenia, bipolar disorder, and healthy controls in relation to brain and clinical characteristics.
6. | Ralph Carmel | Blood | 2017
Explains the biochemical interaction between folate and vitamin B12, including the methylfolate trap and why folic acid can partially correct B12-deficiency anemia without treating neurologic injury.
7. | Multiple authors | Journal of Psychiatric Research | 2017
Meta-analysis finding that people with depression tend to have lower folate levels or dietary folate intake than people without depression.
8. | Dan Wang, Jun-Xia Zhai, Dian-Wu Liu | Psychiatry Research | 2016
Meta-analysis finds decreased serum folate concentrations associated with schizophrenia across multiple study populations.
9. | João Ricardo Araújo et al. | Ageing Research Reviews | 2015
Reviews evidence connecting inadequate folate status in older adults with mild cognitive impairment, dementia, depression, and hyperhomocysteinemia.
10. | Multiple authors | Experimental Gerontology | 2015
Study of nearly 2,000 institutionalized older adults finds folate deficiency alongside a substantial burden of vitamin B12 deficiency.
11. | Edward H. Reynolds | Handbook of Clinical Neurology | 2014
Reviews neurological and psychiatric manifestations associated with folate deficiency and discusses overlap with vitamin B12 deficiency and elevated homocysteine.
12. | Multiple authors | Clinical Interventions in Aging | 2014
Large hospital cohort identifies folate deficiency as one of several contributors associated with anemia in older adults.
13. | Multiple authors | Psychiatry Research | 2011
Finds significantly lower serum and red-cell folate concentrations among schizophrenia patients than matched healthy controls.
14. | Multiple authors | Neurologic Clinics | 2010
Reviews neurological presentations of nutritional deficiencies, including folate deficiency, with additional attention to bariatric surgery and alcohol-related malnutrition.
15. | George I. Papakostas et al. | Journal of Clinical Psychiatry | 2009
Reviews folate formulations in depression, possible neurochemical mechanisms, deficiency-related vulnerability, and evidence for adjunctive folate treatment.
16. | Maureen M. Black | Food and Nutrition Bulletin | 2008
Reviews how folate and vitamin B12 deficiencies may affect brain development, myelination, inflammation, cognition, behavior, and child development.
Meta-analysis examining whether low folate status is associated with depression across observational studies and exploring possible sources of heterogeneity.
18. | Multiple authors | American Journal of Clinical Nutrition | 2007
The Monzino 80-plus study associates low folate concentrations in very old adults with poorer cognitive performance, functional impairment, and dementia.
Reviews evidence for abnormal folate status in schizophrenia while emphasizing important methodological limitations in earlier studies.
20. | Matthew J. Taylor et al. | Journal of Psychopharmacology | 2004
Systematic review and meta-analysis of randomized trials evaluating folate as a treatment or adjunctive treatment for depressive disorders.
21. | Robert Clarke et al. | Age and Ageing | 2004
Population research documents increasing prevalence of metabolically significant folate and vitamin B12 deficiency with advancing age.
22. | Multiple authors | American Journal of Clinical Nutrition | 2003
Evaluates folate, vitamin B12, homocysteine, and methylmalonic acid for identifying functional vitamin deficiencies in older people.
23. | James K. Friel | Journal of Nutrition | 2002
Discusses the longstanding concern that high-dose folate can obscure hematologic signs of vitamin B12 deficiency and reviews the evidence behind the masking concept.
24. | Multiple authors | PubMed-indexed case report | 2001
Describes reversible cognitive impairment in a young adult with bipolar disorder who was found to have folate and vitamin B12 deficiency.
25. | Multiple authors | European Journal of Clinical Nutrition | 2000
Investigates anemia and micronutrient status among community-dwelling older adults and finds substantial folate deficiency in the study population.
26. | Multiple authors | Journal of the American Dietetic Association | 1997
Reviews folate nutrition in older adults, including homocysteine, vascular risk, fortification benefits, and concerns about coexisting vitamin B12 deficiency.
27. | Multiple authors | PubMed-indexed psychiatric study | 1996
Examines anticonvulsant-associated folate deficiency and reports relationships between reduced folate status and psychiatric or cognitive abnormalities.
28. | Multiple authors | Medical Hypotheses | 1994
Explores possible biochemical mechanisms linking folate, vitamin B12, and vitamin B6 deficiencies with neuropsychiatric symptoms through altered homocysteine and sulfur amino-acid metabolism.
29. | M. Passeri et al. | Aging Clinical and Experimental Research | 1993
Clinical trial examines 5-methyltetrahydrofolate treatment for depressive and cognitive symptoms in older adults with organic mental disorders.
30. | P. S. Godfrey et al. | The Lancet | 1990
Randomized trial investigates methylfolate as an adjunct to standard treatment in psychiatric patients with borderline or definite folate deficiency.
31. | Multiple authors | PubMed-indexed review | 1989
Reviews relationships among folate deficiency, depression, psychiatric symptoms, neurotransmitter metabolism, anticonvulsant therapy, and folate supplementation.
32. | C. Infante-Rivard et al. | Journal of the American Geriatrics Society | 1986
Reports red-cell folate deficiency among institutionalized older adults and explores length of institutional stay as a public-health risk factor.
33. | E. H. Reynolds, M. W. Carney, B. K. Toone | The Lancet | 1984
Explores methylation pathways as a possible explanation for depression and other neuropsychiatric manifestations of severe folate deficiency.
34. | S. G. Webster, J. T. Leeming | Journal of the American Geriatrics Society | 1979
Compares erythrocyte folate concentrations in young and elderly populations and finds low levels relatively common among older groups.
35. | E. H. Reynolds, P. Rothfeld, J. H. Pincus | British Medical Journal | 1973
Reports greater neurologic abnormalities among hospitalized patients with severe folate deficiency than among controls with normal folate levels.
Cancer, DNA Damage, and Genome Stability
1. | Multiple authors | Journal of Cell Biology | 2025
Reviews mechanisms by which folate depletion can destabilize the genome, including impaired nucleotide synthesis and other forms of cellular folate stress.
2. | Renee Pieroth et al. | Current Nutrition Reports | 2018
Reviews evidence linking folate status to cancer risk and notes that low or deficient folate has been associated with increased risk in several cancer types.
3. | Multiple authors | International Journal of Cancer | 2015
Meta-analysis of 83 case-control studies finding associations between elevated homocysteine, low folate, and increased overall cancer risk.
4. | Michael Fenech | Mutation Research | 2012
Reviews folate and vitamin B12 in maintenance of nuclear and mitochondrial genome integrity, including chromosome breaks, micronuclei, uracil incorporation, and methylation.
5. | Hamid M. Said et al. | Alcohol | 2009
Reviews alcohol-induced folate malabsorption, disturbed one-carbon metabolism, epigenetic instability, and possible links between chronic alcohol exposure and cancer development.
6. | Young-In Kim | Journal of Nutrition | 2004
Examines DNA methylation as a possible mechanistic link between folate deficiency and colorectal carcinogenesis while emphasizing the complexity of available evidence.
7. | Guo-Min Li | Journal of Nutritional Biochemistry | 2003
Reviews evidence that folate deficiency can promote genomic instability and apoptosis through DNA mismatch-repair pathways.
8. | Young-In Kim | Journal of Nutrition | 2002
Reviews interactions among folate status, genetic polymorphisms, DNA methylation, and genomic regulation, including the effects of inadequate methyl-group supply.
9. | Bruce N. Ames et al. | Proceedings of the National Academy of Sciences | 1997
Demonstrates that folate deficiency increases uracil incorporation into human DNA and chromosome breakage, offering a mechanism for disease associated with low folate.
10. | S. A. Glynn, D. Albanes | Nutrition and Cancer | 1994
Reviews experimental and epidemiological evidence that inadequate folate may promote carcinogenesis through effects on DNA synthesis and methylation.
Homocysteine and Cardiovascular Disease
1. | Multiple authors | BMC Nutrition | 2026
Systematic review and meta-analysis of randomized trials showing that folic acid lowers homocysteine in adults with hyperhomocysteinemia and examining cardiovascular surrogate markers.
2. | J. David Spence | International Journal of Stroke | 2016
Reviews evidence on homocysteine lowering for stroke prevention and the role of folate and other B vitamins in modifying vascular risk.
3. | Henk J. Blom, Yvo Smulders | Journal of Inherited Metabolic Disease | 2011
Reviews folate and homocysteine metabolism and explains why abnormalities in these pathways are relevant to cardiovascular disease, neural tube defects, and other disorders.
4. | Anthony S. Wierzbicki | Diabetes & Vascular Disease Research | 2007
Reviews the evidence linking elevated homocysteine with cardiovascular disease and notes folate and B-vitamin deficiency among important causes of hyperhomocysteinemia.
5. | Graeme J. Hankey | Current Opinion in Neurology | 2001
Reviews homocysteine and stroke risk and discusses folate deficiency as one of several factors that can elevate plasma homocysteine.
Cerebral Folate Deficiency
1. | Multiple authors | Nutrients | 2022
Reviews early diagnosis and treatment of cerebral folate deficiency syndrome, including folate-receptor autoimmunity and inherited disorders.
2. | Daniel A. Rossignol, Richard E. Frye | Journal of Personalized Medicine | 2021
Systematic review and meta-analysis examines cerebral folate deficiency, folate-receptor-alpha autoantibodies, autism, and folinic acid treatment.
3. | V. Th. Ramaekers et al. | Molecular Genetics and Metabolism | 2018
Evaluates genetic abnormalities and folate-receptor autoantibodies in children with infantile-onset cerebral folate deficiency syndrome.
4. | Vincent Th. Ramaekers | Clinical Chemistry and Laboratory Medicine | 2013
Reviews recognition, causes, clinical presentations, testing, and treatment of cerebral folate deficiency syndromes.
5. | Multiple authors | Clinical Chemistry and Laboratory Medicine | 2013
Reviews measurement and diagnostic significance of folate-receptor autoantibodies in cerebral folate deficiency and pregnancy-related disorders.
6. | Multiple authors | Developmental Medicine & Child Neurology | 2010
Reviews cerebral folate deficiency as a treatable neurological syndrome characterized by low cerebrospinal-fluid 5-methyltetrahydrofolate despite normal peripheral folate.
7. | Vincent T. Ramaekers et al. | New England Journal of Medicine | 2005
Landmark study identifies folate-receptor-blocking autoantibodies in children with cerebral folate deficiency and reports improvement after folinic acid therapy.
