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Fardous AM, Heydari AR. Uncovering the Hidden Dangers and Molecular Mechanisms of Excess Folate: A Narrative Review. Nutrients 2023; 15:4699. [PMID: 37960352 PMCID: PMC10648405 DOI: 10.3390/nu15214699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/26/2023] [Accepted: 11/03/2023] [Indexed: 11/15/2023] Open
Abstract
This review delves into the intricate relationship between excess folate (vitamin B9) intake, especially its synthetic form, namely, folic acid, and its implications on health and disease. While folate plays a pivotal role in the one-carbon cycle, which is essential for DNA synthesis, repair, and methylation, concerns arise about its excessive intake. The literature underscores potential deleterious effects, such as an increased risk of carcinogenesis; disruption in DNA methylation; and impacts on embryogenesis, pregnancy outcomes, neurodevelopment, and disease risk. Notably, these consequences stretch beyond the immediate effects, potentially influencing future generations through epigenetic reprogramming. The molecular mechanisms underlying these effects were examined, including altered one-carbon metabolism, the accumulation of unmetabolized folic acid, vitamin-B12-dependent mechanisms, altered methylation patterns, and interactions with critical receptors and signaling pathways. Furthermore, differences in the effects and mechanisms mediated by folic acid compared with natural folate are highlighted. Given the widespread folic acid supplementation, it is imperative to further research its optimal intake levels and the molecular pathways impacted by its excessive intake, ensuring the health and well-being of the global population.
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Affiliation(s)
- Ali M. Fardous
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA;
| | - Ahmad R. Heydari
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA;
- Barbara Ann Karmanos Cancer Institute, Wayne State University, Detroit, MI 48202, USA
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2
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Cochrane KM, Elango R, Devlin AM, Hutcheon JA, Karakochuk CD. Human milk unmetabolized folic acid is increased following supplementation with synthetic folic acid as compared to (6S)-5-methyltetrahydrofolic acid. Sci Rep 2023; 13:11298. [PMID: 37438496 DOI: 10.1038/s41598-023-38224-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 07/05/2023] [Indexed: 07/14/2023] Open
Abstract
Folic acid supplementation is recommended perinatally, but may increase unmetabolized folic acid (UMFA) in human milk; this is concerning as it is an inactive form which may be less bioavailable for the infant. "Natural" (6S)-5-methyltetrahydrofolic acid [(6S)-5-MTHF] is available as an alternative to folic acid, and may prevent the accumulation of UMFA in human milk. Pregnant women (n = 60) were enrolled at 8-21 weeks of gestation and randomized to 0.6 mg/day folic acid or (6S)-5-MTHF. At ~ 1-week postpartum, participants provided a human milk specimen. Total human milk folate (nmol/L) and concentrations of UMFA (nmol/L) were quantified via LC-MS/MS. Differences between groups were evaluated using multivariable quantile/linear regression, adjusting for dietary folate, weeks supplementing, and milk collection methods. No significant difference in total milk folate was found; however, the median milk UMFA concentration was 11 nmol/L higher in those receiving folic acid versus (6S)-5-MTHF (95% CI = 6.4-17 nmol/L), with UMFA representing 28% and 2% of total milk folate. In conclusion, the form of supplemental folate had markedly differential effects on the human milk folate profile, with folic acid increasing the mean proportion of milk UMFA by ~ 14-fold. Investigation of whether increased UMFA impacts folate-related metabolism and infant health outcomes is required.
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Affiliation(s)
- Kelsey M Cochrane
- Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, BC, V6T 1Z4, Canada
- BC Children's Hospital Research Institute, Healthy Starts, Vancouver, Canada
| | - Rajavel Elango
- BC Children's Hospital Research Institute, Healthy Starts, Vancouver, Canada
- Department of Paediatrics, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
- Population and Public Health, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - Angela M Devlin
- BC Children's Hospital Research Institute, Healthy Starts, Vancouver, Canada
- Department of Paediatrics, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - Jennifer A Hutcheon
- BC Children's Hospital Research Institute, Healthy Starts, Vancouver, Canada
- Department of Obstetrics and Gynaecology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - Crystal D Karakochuk
- Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, BC, V6T 1Z4, Canada.
- BC Children's Hospital Research Institute, Healthy Starts, Vancouver, Canada.
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3
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Ledowsky CJ, Schloss J, Steel A. Variations in folate prescriptions for patients with the MTHFR genetic polymorphisms: A case series study. EXPLORATORY RESEARCH IN CLINICAL AND SOCIAL PHARMACY 2023; 10:100277. [PMID: 37228355 PMCID: PMC10205484 DOI: 10.1016/j.rcsop.2023.100277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 03/16/2023] [Accepted: 04/30/2023] [Indexed: 05/27/2023] Open
Abstract
Background Over 48.5 million couples are reported with infertility worldwide. Health policy recommends folic acid in women of childbearing age, particularly in preconception and pregnancy which results in women purchasing over-the-counter prenatal multivitamins containing folic acid through pharmacies and other retail outlets. Emerging studies are investigating whether other forms of supplemental folate are more suitable, particularly for those with methylenetetrahydrofolate reductase (MTHFR) polymorphisms. This case series aimed to document variations in forms and dosage of folate prescribed by Australian practitioners to patients with diagnosed infertility and MTHFR polymorphisms. Methods Australian practitioners were invited to complete a retrospective case report form for patients that presented with unexplained infertility. This case report form documented the form and dose of folate that practitioners were prescribing to their infertility patient with MTHFR polymorphisms, together with their fertility history. Results Six practitioners submitted case information for 12 patients with diagnosed infertility and MTHFR polymorphisms. All patients had been advised by their practitioner to remove folic acid in supplemental form and were prescribed 5-methyltetrahydrofolate (5-MTHF) or a combination of 5-MTHF and folinic acid, at higher doses than the Australian recommended dose (mean daily maximum prescribed dose: 2325μg). Eleven patients conceived within the treatment period (average treatment of one year) and ten were reported as having a live birth. Conclusion This case series has highlighted clinical practices that vary from the recommendations by Australian policy. Further research is required to verify the clinical importance of variations in folate prescriptions for women with MTHFR polymorphisms and how folate recommendations may need to change depending on these polymorphisms. This has direct relevance to those prescribing at the pharmacy and retail level, specifically pharmacists and pharmacy assistants.
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Affiliation(s)
- Carolyn Jane Ledowsky
- Endeavour College of Natural Health, now at University of Technology Sydney, Faculty of Health, Australia
| | - Janet Schloss
- Southern Cross University, Natural Centre for Naturopathic Medicine, Lismore, NSW, Australia
| | - Amie Steel
- University of Technology Sydney, Faculty of Health, Australia
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4
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Bobrowski-Khoury N, Sequeira JM, Quadros EV. Brain Uptake of Folate Forms in the Presence of Folate Receptor Alpha Antibodies in Young Rats: Folate and Antibody Distribution. Nutrients 2023; 15:nu15051167. [PMID: 36904166 PMCID: PMC10005127 DOI: 10.3390/nu15051167] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
In a rat model, following exposure to rat folate receptor alpha antibodies (FRαAb) during gestation, FRαAb accumulates in the placenta and the fetus and blocks folate transport to the fetal brain and produces behavioral deficits in the offspring. These deficits could be prevented with folinic acid. Therefore, we sought to evaluate folate transport to the brain in young rat pups and determine what effect FRαAb has on this process, to better understand the folate receptor autoimmune disorder associated with cerebral folate deficiency (CFD) in autism spectrum disorders (ASD). When injected intraperitoneally (IP), FRαAb localizes to the choroid plexus and blood vessels including the capillaries throughout the brain parenchyma. Biotin-tagged folic acid shows distribution in the white matter tracts in the cerebrum and cerebellum. Since these antibodies can block folate transport to the brain, we orally administered various folate forms to identify the form that is better-absorbed and transported to the brain and is most effective in restoring cerebral folate status in the presence of FRαAb. The three forms of folate, namely folic acid, D,L-folinic acid and levofolinate, are converted to methylfolate while L-methylfolate is absorbed as such and all are efficiently distributed to the brain. However, significantly higher folate concentration is seen in the cerebrum and cerebellum with levofolinate in the presence or absence of FRαAb. Our results in the rat model support testing levofolinate to treat CFD in children with ASD.
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Affiliation(s)
| | - Jeffrey M. Sequeira
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Edward V. Quadros
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA
- Correspondence:
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5
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Alnabbat KI, Fardous AM, Shahab A, James AA, Bahry MR, Heydari AR. High Dietary Folic Acid Intake Is Associated with Genomic Instability in Peripheral Lymphocytes of Healthy Adults. Nutrients 2022; 14:3944. [PMID: 36235597 PMCID: PMC9571807 DOI: 10.3390/nu14193944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/16/2022] [Accepted: 09/22/2022] [Indexed: 11/17/2022] Open
Abstract
Mandatory fortification of food with synthetic folic acid (FA) was instituted in 1998 to reduce the incidence of neural tube defects. Adequate folate status is correlated with numerous health benefits. However, elevated consumption of FA is controversially associated with deleterious effects on health. We previously reported that excess FA mimicked folate depletion in a lymphoblastoid cell line. To explore the impact of FA intake from fortified food, we conducted an observational human study on 33 healthy participants aged 18-40 not taking any supplements. Food intake, anthropomorphic measurements, and blood samples were collected and analyzed. Our results show that individuals belonging to the highest tertile of folic acid intake, as well as ones with the highest folic acid to total folate intake ratio (FAR), display a significantly greater incidence of lymphocyte genomic damage. A decrease in global DNA methylation is observed in the highest tertile of FAR compared to the lowest (p = 0.055). A downward trend in the overall gene expression of select DNA repair and one carbon cycle genes (MGMT, MLH1, UNG, MTHFR, MTR) is noted with increased folate status and FA intake. These results provide supporting evidence that high consumption of FA from fortified foods can precipitate genomic instability in peripheral lymphocyte in vivo.
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Affiliation(s)
- Khadijah I Alnabbat
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
- Department of Food and Nutrition Sciences, King Faisal University, Al Hufūf 31982, Saudi Arabia
| | - Ali M Fardous
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
| | - Aiman Shahab
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
| | - Andrew A James
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
| | - Manhel R Bahry
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
| | - Ahmad R Heydari
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
- Barbara Ann Karmanos Cancer Institute, Wayne State University, Detroit, MI 48202, USA
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6
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Bobrowski-Khoury N, Sequeira JM, Arning E, Bottiglieri T, Quadros EV. Absorption and Tissue Distribution of Folate Forms in Rats: Indications for Specific Folate Form Supplementation during Pregnancy. Nutrients 2022; 14:nu14122397. [PMID: 35745126 PMCID: PMC9228663 DOI: 10.3390/nu14122397] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/05/2022] [Accepted: 06/07/2022] [Indexed: 01/27/2023] Open
Abstract
Food fortification and folic acid supplementation during pregnancy have been implemented as strategies to prevent fetal malformations during pregnancy. However, with the emergence of conditions where folate metabolism and transport are disrupted, such as folate receptor alpha autoantibody (FRαAb)-induced folate deficiency, it is critical to find a folate form that is effective and safe for pharmacologic dosing for prolonged periods. Therefore, in this study, we explored the absorption and tissue distribution of folic acid (PGA), 5-methyl-tetrahydrofolate (MTHF), l-folinic acid (levofolinate), and d,l-folinic acid (Leucovorin) in adult rats. During absorption, all forms are converted to MTHF while some unconverted folate form is transported into the blood, especially PGA. The study confirms the rapid distribution of absorbed folate to the placenta and fetus. FRαAb administered, also accumulates rapidly in the placenta and blocks folate transport to the fetus and high folate concentrations are needed to circumvent or overcome the blocking of FRα. In the presence of FRαAb, both Leucovorin and levofolinate are absorbed and distributed to tissues better than the other forms. However, only 50% of the leucovorin is metabolically active whereas levofolinate is fully active and generates higher tetrahydrofolate (THF). Because levofolinate can readily incorporate into the folate cycle without needing methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MS) in the first pass and is relatively stable, it should be the folate form of choice during pregnancy, other disorders where large daily doses of folate are needed, and food fortification.
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Affiliation(s)
- Natasha Bobrowski-Khoury
- The School of Graduate Studies, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA;
| | - Jeffrey M. Sequeira
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA;
| | - Erland Arning
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75204, USA; (E.A.); (T.B.)
| | - Teodoro Bottiglieri
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75204, USA; (E.A.); (T.B.)
| | - Edward V. Quadros
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA;
- Correspondence:
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7
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WU H, ZHANG Z, WANG Y, ZHANG T, QI S, TANG Y, GAO X. Investigation into the Properties of L-5-Methyltetrahydrofolate and Seal Oil as a Potential Atherosclerosis Intervention in Rats. J Nutr Sci Vitaminol (Tokyo) 2022; 68:87-96. [DOI: 10.3177/jnsv.68.87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Hong WU
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
| | - Zhengduo ZHANG
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
| | - Yuxin WANG
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
| | - Tianran ZHANG
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
| | - Shaojun QI
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
| | - Yanjin TANG
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
| | - Xibao GAO
- Department of Physical and Chemical Inspection, School of Public Health, Cheeloo College of Medicine, Shandong University
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8
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Excessive Folic Acid Mimics Folate Deficiency in Human Lymphocytes. Curr Issues Mol Biol 2022; 44:1452-1462. [PMID: 35723355 PMCID: PMC9164024 DOI: 10.3390/cimb44040097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/14/2022] [Accepted: 03/20/2022] [Indexed: 12/19/2022] Open
Abstract
Food fortification with synthetic folic acid (FA), along with supplementation, results in a marked increase in the population total of serum folates and unmetabolized folic acid (UMFA). Despite the success in reducing neural tube defects at birth in the intended target population (women of childbearing age), the potential deleterious effects of chronically high levels of UMFA in susceptible segments of the population require further investigation. In this study, we examine the effects of FA concentrations, ranging from depletion to supraphysiological levels, on markers of proliferation, DNA methylation, and DNA damage and repair in a human lymphoblastoid cell line (LCL). We note that both low and high levels of FA similarly impact global DNA methylation, cytome biomarkers measured through the CBMN assay, DNA damage induced by oxidative stress, and DNA base excision repair gene expression.
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9
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OUP accepted manuscript. Nutr Rev 2022; 80:1985-2001. [DOI: 10.1093/nutrit/nuac015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Maher A, Sobczyńska-Malefora A. The Relationship Between Folate, Vitamin B12 and Gestational Diabetes Mellitus With Proposed Mechanisms and Foetal Implications. J Family Reprod Health 2021; 15:141-149. [PMID: 34721605 PMCID: PMC8536822 DOI: 10.18502/jfrh.v15i3.7131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The incidence of gestational diabetes mellitus (GDM) is rising, which warrants attention due to the associated complications during pregnancy and in the long term for both mother and offspring. Studies have suggested a relationship between maternal folate (vitamin B9) and vitamin B12 status and GDM risk. Seemingly the most problematic scenario occurs when there is B-vitamin imbalance, with high folate and low vitamin B12. This nutritional state can occur in vitamin B12 deficient women who exceed the recommended folic acid supplementation. However, the pathological mechanisms behind this relationship are currently unclear and are explored in this review article. A high folate/low B12 can lead to a functional folate deficiency through the methyl-trap phenomenon, impairing re-methylation of homocysteine and regeneration of folates for DNA synthesis and repair. Consequently elevated homocysteine concentration leads to endothelial dysfunction and oxidative stress. Vitamin B12 deficiency also leads to an impairment of the conversion of methylmalonyl-CoA to succinyl-CoA, which has been associated with insulin resistance. Insulin resistance is thought to contribute to the etiology of GDM. More studies are needed to confirm the impact of these and other mechanisms on disease development. However, it highlights a potential avenue for GDM risk modification through a vitamin B12 supplement and improvement of maternal metabolic health.
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Affiliation(s)
- Angeline Maher
- Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Agata Sobczyńska-Malefora
- Faculty of Life Sciences & Medicine, Kings College London, London, UK.,Nutristasis Unit, Viapath, St. Thomas' Hospital, London, UK
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11
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Husebye ESN, Riedel B, Bjørke-Monsen AL, Spigset O, Daltveit AK, Gilhus NE, Bjørk MH. Vitamin B status and association with antiseizure medication in pregnant women with epilepsy. Epilepsia 2021; 62:2968-2980. [PMID: 34590314 DOI: 10.1111/epi.17076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/23/2021] [Accepted: 09/07/2021] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Antiseizure medication (ASM) use interacts with vitamin B status in nonpregnant epilepsy populations. We aimed to examine the association between ASM and vitamin B status in pregnant women with epilepsy. METHODS We performed a cross-sectional study of pregnancies in women with epilepsy enrolled in the Norwegian Mother, Father and Child Cohort Study from 1999 to 2008. Data on ASM and vitamin supplement use were collected from questionnaires. We analyzed maternal plasma concentrations of ASM and metabolites of folate, including unmetabolized folic acid (UMFA), riboflavin (vitamin B2), pyridoxine (vitamin B6), and niacin (vitamin B3) during gestational weeks 17-19. RESULTS We included 227 singleton pregnancies exposed to ASM with available plasma samples (median maternal age 29 years, range 18 to 41 years). From the preconception period to gestational week 20, any supplement of folic acid was reported in 208 of pregnancies (94%), riboflavin in 72 (33%), pyridoxine in 77 (35%), and niacin in 45 (20%). High ASM concentrations correlated with high concentrations of UMFA and inactive folate metabolites, and with low concentrations of riboflavin and metabolically active pyridoxine. There was no association between ASM and niacin status. SIGNIFICANCE ASM concentrations during pregnancy were associated with vitamin B status in pregnant women with epilepsy. Additional studies are needed to determine the clinical impact of these findings, and to define the optimal vitamin doses that should be recommended to improve pregnancy outcomes.
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Affiliation(s)
- Elisabeth Synnøve Nilsen Husebye
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.,Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Bettina Riedel
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Anne-Lise Bjørke-Monsen
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Olav Spigset
- Department of Clinical Pharmacology, St. Olav University Hospital, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Anne Kjersti Daltveit
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Department of Health Registries, Norwegian Institute of Public Health, Bergen, Norway
| | - Nils Erik Gilhus
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.,Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Marte Helene Bjørk
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.,Department of Neurology, Haukeland University Hospital, Bergen, Norway
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12
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Rose EG, Murphy MSQ, Erwin E, Muldoon KA, Harvey ALJ, Rennicks White R, MacFarlane AJ, Wen SW, Walker MC. Gestational Folate and Folic Acid Intake among Women in Canada at Higher Risk of Pre-Eclampsia. J Nutr 2021; 151:1976-1982. [PMID: 33851221 PMCID: PMC8245867 DOI: 10.1093/jn/nxab063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/16/2020] [Accepted: 02/19/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Periconceptional folic acid (FA) supplementation is recommended to prevent neural tube defects; however, the extent to which recommendations are met through dietary sources and supplements is not clear. OBJECTIVES Our objective was to evaluate the dietary and supplemental intakes of FA in a Canadian pregnancy cohort and to determine the proportions of pregnant women exceeding the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL). METHODS FACT (the Folic Acid Clinical Trial) was an international multicenter, randomized, double-blinded, placebo-controlled, phase III trial investigating FA for the prevention of pre-eclampsia in high-risk pregnancies. Participants were enrolled from Canadian sites at 8-16 weeks of gestation. Dietary and supplemental FA intake data were collected through participant interviews and FFQs at the time of FACT enrollment. Categorical data were summarized as n (%) and continuous data as median (IQR). RESULTS This study included 1198 participants. Participants consumed 485 μg dietary folate equivalents (DFE)/d (IQR: 370-630 μg DFE/d) from dietary sources of folate and FA. Through diet alone, 43.4% of participants consumed ≥520 μg DFE/d, the EAR for pregnant individuals. Of the 91.9% of participants who consumed daily FA supplements, 0.4% consumed <400 μg FA/d and 96.0% consumed ≥1000 μg/d, the UL for FA. Median (IQR) total folate intake was 2167 μg DFE/d (2032-2325 μg DFE/d); 95.3% of participants met or exceeded the EAR from all sources, but 1069 (89.2%) participants exceeded the UL. CONCLUSIONS The majority of participants in this Canadian pregnancy cohort did not consume the recommended amount of folate from dietary sources. However, most prenatal supplements contained 1000 μg FA, resulting in the majority of women exceeding the UL. With no additional benefit associated with FA intakes beyond the UL for most women, modification of prenatal supplement formulations may be warranted to ensure women meet but do not exceed recommended FA intakes.FACT was registered at clinicaltrials.gov as NCT01355159 and at isrctn.com as ISRCTN23781770.
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Affiliation(s)
- Elaine G Rose
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Malia S Q Murphy
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Erica Erwin
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada,BORN Ontario, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Katherine A Muldoon
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Alysha L J Harvey
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Ruth Rennicks White
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada,Department of Obstetrics, Gynecology & Newborn Care, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Amanda J MacFarlane
- Nutrition Research Division, Health Canada, Ottawa, Ontario, Canada,Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Shi Wu Wen
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada,Department of Obstetrics, Gynecology & Newborn Care, The Ottawa Hospital, Ottawa, Ontario, Canada,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada,Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
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13
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Penailillo RS, Eckert JJ, Burton MA, Burdge GC, Fleming TP, Lillycrop KA. High maternal folic acid intake around conception alters mouse blastocyst lineage allocation and expression of key developmental regulatory genes. Mol Reprod Dev 2021; 88:261-273. [PMID: 33719134 DOI: 10.1002/mrd.23462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 02/05/2021] [Accepted: 02/20/2021] [Indexed: 12/16/2022]
Abstract
Folate, a cofactor for the supply of one-carbon groups, is required by epigenetic processes to regulate cell lineage determination during development. The intake of folic acid (FA), the synthetic form of folate, has increased significantly over the past decade, but the effects of high periconceptional FA intake on cell lineage determination in the early embryo remains unknown. Here, we investigated the effect of maternal high FA (HFA) intake on blastocyst development and expression of key regulatory genes. C57BL/6 adult female mice were fed either Control diet (1 mg FA) for 4 weeks before conception and during the preimplantation period (Con-Con); Control diet for 4 weeks preconception, followed by HFA (5 mg FA) diet during preimplantation (Con-HFA); or HFA diet for 4 weeks preconception and during preimplantation (HFA-HFA). At E3.5, blastocyst cell number, protein, and mRNA expression were measured. In HFA-HFA blastocysts, trophectoderm cell numbers and expression of CDX2, Oct-4, and Nanog were reduced compared with Con-Con blastocysts; Con-HFA blastocysts showed lower CDX2 and Oct-4 expression than Con-Con blastocysts. These findings suggest periconceptional HFA intake induces changes in key regulators of embryo morphogenesis with potential implications for subsequent development.
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Affiliation(s)
- R S Penailillo
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - J J Eckert
- School of Human Health and Development, University of Southampton, Southampton, UK
| | - M A Burton
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - G C Burdge
- School of Human Health and Development, University of Southampton, Southampton, UK
| | - T P Fleming
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - K A Lillycrop
- Centre for Biological Sciences, University of Southampton, Southampton, UK
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Murphy MSQ, Muldoon KA, Sheyholislami H, Behan N, Lamers Y, Rybak N, White RR, Harvey ALJ, Gaudet LM, Smith GN, Walker MC, Wen SW, MacFarlane AJ. Impact of high-dose folic acid supplementation in pregnancy on biomarkers of folate status and 1-carbon metabolism: An ancillary study of the Folic Acid Clinical Trial (FACT). Am J Clin Nutr 2021; 113:1361-1371. [PMID: 33675351 PMCID: PMC8106758 DOI: 10.1093/ajcn/nqaa407] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 12/04/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Periconceptional folic acid (FA) supplementation is recommended to prevent the occurrence of neural tube defects. Currently, most over-the-counter FA supplements in Canada and the United States contain 1 mg FA and some women are prescribed 5 mg FA/d. High-dose FA is hypothesized to impair 1-carbon metabolism. We aimed to determine folate and 1-carbon metabolism biomarkers in pregnant women exposed to 1 mg or 5 mg FA. OBJECTIVES This was an ancillary study within the Folic Acid Clinical Trial (FACT), a randomized, double-blinded, placebo-controlled, phase III trial designed to assess the efficacy of high-dose FA to prevent preeclampsia. METHODS For FACT, women were randomized at 8-16 gestational weeks to receive daily 4.0 mg FA (high dose) or placebo (low dose) plus their usual supplementation (≤1.1 mg). Women were recruited from 3 Canadian FACT centers and provided nonfasting blood samples at 24-26 gestational weeks for measurement of RBC and serum total folate, serum unmetabolized FA (UMFA), tetrahydrofolate (THF), 5-methylTHF, 5-formylTHF, 5,10-methenylTHF, and MeFox (pyrazino-s-triazine derivative of 4α-hydroxy-5-methylTHF, a 5-methylTHF oxidation product); total vitamins B-12 and B-6; and plasma total homocysteine. Group differences were determined using χ2, Fisher exact, and Wilcoxon rank-sum tests. RESULTS Nineteen (38%) women received high-dose FA and 31 (62%) received low-dose FA. The median RBC folate concentration was 2701 (IQR: 2243-3032) nmol/L and did not differ between groups. The high-dose group had higher serum total folate (median: 148.4 nmol/L, IQR: 110.4-181.2; P = 0.007), UMFA (median: 4.6 nmol/L, IQR: 2.5-33.8; P = 0.008), and 5-methylTHF (median: 126.6 nmol/L, IQR: 98.8-158.6; P = 0.03) compared with the low-dose group (median: 122.8 nmol/L, IQR: 99.5-136.0; median: 1.9 nmol/L, IQR: 0.9-4.1; median: 108.6 nmol/L, IQR: 96.4-123.2, respectively). Other biomarkers of 1-carbon metabolism did not differ. CONCLUSIONS High-dose FA supplementation in early pregnancy increases maternal serum folate but not RBC folate concentrations, suggesting tissue saturation. Higher UMFA concentrations in women receiving high-dose FA supplements suggest that these doses are supraphysiologic but with no evidence of altered 1-carbon metabolism.
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Affiliation(s)
- Malia S Q Murphy
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Katherine A Muldoon
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Hauna Sheyholislami
- Nutrition Research Division, Health Canada, Ottawa, Ontario, Canada
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Nathalie Behan
- Nutrition Research Division, Health Canada, Ottawa, Ontario, Canada
| | - Yvonne Lamers
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Natalie Rybak
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics, Gynecology, & Newborn Care, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Ruth Rennicks White
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics, Gynecology, & Newborn Care, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Alysha L J Harvey
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Laura M Gaudet
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, Kingston Health Sciences Centre, Kingston, Ontario, Canada
- Department of Obstetrics and Gynecology, Queen's University, Kingston, Ontario, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
| | - Graeme N Smith
- Department of Obstetrics and Gynecology, Kingston Health Sciences Centre, Kingston, Ontario, Canada
- Department of Obstetrics and Gynecology, Queen's University, Kingston, Ontario, Canada
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Mark C Walker
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics, Gynecology, & Newborn Care, The Ottawa Hospital, Ottawa, Ontario, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
- BORN Ontario, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
- CHEO Research Institute, Ottawa, Ontario, Canada
| | - Shi Wu Wen
- OMNI Research Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
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Raghavan R, Selhub J, Paul L, Ji Y, Wang G, Hong X, Zuckerman B, Fallin MD, Wang X. A prospective birth cohort study on cord blood folate subtypes and risk of autism spectrum disorder. Am J Clin Nutr 2020; 112:1304-1317. [PMID: 32844208 PMCID: PMC7657337 DOI: 10.1093/ajcn/nqaa208] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 07/07/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND We previously reported that extremely high concentrations of maternal plasma folate were associated with increased risk of autism spectrum disorder (ASD) in children. This study explored whether specific types of folate in cord blood have differential association with ASD. OBJECTIVES In the Boston Birth Cohort (BBC), we assessed the association between cord blood unmetabolized folic acid (UMFA), 5-methyl tetrahydrofolate (THF), and total folate and a child's ASD risk. In a subset, we explored whether the association between UMFA and ASD risk can be affected by the dihydrofolate reductase (DHFR) genotype and cord plasma creatinine. We also examined prenatal correlates of cord UMFA concentrations. METHODS This report included 567 BBC children (92 ASD, 475 neurotypical), who were recruited at birth and prospectively followed at the Boston Medical Center. ASD was defined from International Classification of Diseases (ICD)-9 and ICD-10 codes documented in electronic medical records. RESULTS Children with cord UMFA in the highest, versus lowest quartile, had a greater ASD risk (adjusted OR, aORquartile4: 2.26; 95% CI: 1.08, 4.75). When stratified by race/ethnicity, the association was limited to 311 (45 ASD) Black children (aORquartile4: 9.85; 95% CI: 2.53, 38.31); a test of interaction between race/ethnicity and cord UMFA concentrations was significant (P = 0.007). The UMFA-ASD association in Black children slightly attenuated after adjusting for cord plasma creatinine (P = 0.05). There was no significant association between cord 5-methyl THF, total folate, DHFR genotype, and ASD risk. Cord total folate and maternal supplement intake during second trimester were associated with higher cord UMFA. CONCLUSIONS Higher concentrations of cord UMFA, but not 5-methyl THF or total folate, were associated with a greater risk of ASD in Black children. This study in a preterm-birth-enriched cohort raises more questions than it could answer and underscores the need for additional investigations on the sources and role of cord UMFA in children's neurodevelopmental outcomes and underlying mechanisms.
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Affiliation(s)
- Ramkripa Raghavan
- Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jacob Selhub
- Jean Mayer USDA Human Nutrition Research Center for Aging at Tufts University, Boston, MA, USA
| | - Ligi Paul
- Jean Mayer USDA Human Nutrition Research Center for Aging at Tufts University, Boston, MA, USA
| | - Yuelong Ji
- Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Guoying Wang
- Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Xiumei Hong
- Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Barry Zuckerman
- Department of Pediatrics, Boston University School of Medicine and Boston Medical Center, Boston, MA, USA
| | - M Daniele Fallin
- Department of Mental Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
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Folic acid content of diet during pregnancy determines post-birth re-set of metabolism in Wistar rat dams. J Nutr Biochem 2020; 83:108414. [PMID: 32544644 DOI: 10.1016/j.jnutbio.2020.108414] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 03/11/2020] [Accepted: 05/02/2020] [Indexed: 12/13/2022]
Abstract
Maternal metabolism begins to return to homeostasis (re-set) following birth and is accelerated by lactation. Delay in metabolic re-set may contribute to postpartum weight retention and later-life metabolic consequences. Folic acid (FA) is essential during pregnancy but inadequate intakes may alter 1-carbon metabolism, consequently affecting energy homeostatic systems. Our objectives were to examine the effects of FA content 1)below and 2)above requirements during pregnancy on the re-set of body weight, markers of hepatic 1-carbon metabolism and central and peripheral energy metabolic pathways in Wistar rat mothers early post-weaning (PW) compared to pregnant controls. Pregnant Wistar rats were fed an AIN-93G diet with FA at 0X, 1X (control, 2 mg FA/kg) or a range above requirements at 2.5X, 5X or 10X recommended levels then the control diet during lactation up to 1 week PW. Dams fed below (0X) or above (5X and 10X) FA requirements had delayed weight-loss from weaning up to 1 week PW, higher plasma insulin and HOMA-IR and changes in glucose and lipid metabolism-regulating genes in muscle, but not liver or adipose tissue compared to controls. Expression of folate-related genes in liver were lower in high FA fed dams. Central food intake neurons were not affected by FA diets. In conclusion, intakes of FA below (0X) or above (5X, 10X) requirements during pregnancy delayed weight-loss, dysregulated 1-carbon pathways in the liver and peripheral energy metabolic pathways in the Wistar rat mother up to 4 weeks after dietary exposure; potentially programming long-term negative metabolic effects and that of her future offspring.
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Cochrane KM, Mayer C, Devlin AM, Elango R, Hutcheon JA, Karakochuk CD. Is natural (6S)-5-methyltetrahydrofolic acid as effective as synthetic folic acid in increasing serum and red blood cell folate concentrations during pregnancy? A proof-of-concept pilot study. Trials 2020; 21:380. [PMID: 32370802 PMCID: PMC7201521 DOI: 10.1186/s13063-020-04320-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 04/10/2020] [Indexed: 01/21/2023] Open
Abstract
Background North American health authorities recommend 0.4 mg/day folic acid before conception and throughout pregnancy to reduce the risk of neural tube defects. Folic acid is a synthetic form of folate that must be reduced by dihydrofolate reductase and then further metabolized. Recent evidence suggests that the maximal capacity for this process is limited and unmetabolized folic acid has been detected in the circulation. The biological effects of unmetabolized folic acid are unknown. A natural form of folate, (6S)-5-methyltetrahydrofolic acid (Metafolin®), may be a superior alternative because it does not need to be reduced in the small intestine. Metafolin® is currently used in some prenatal multivitamins; however, it has yet to be evaluated during pregnancy. Methods/design This double-blind, randomized trial will recruit 60 pregnant women aged 19–42 years. The women will receive either 0.6 mg/day folic acid or an equimolar dose (0.625 mg/day) of (6S)-5-methyltetrahydrofolic acid for 16 weeks. The trial will be initiated at 8–21 weeks’ gestation (after neural tube closure) to reduce the risk of harm should (6S)-5-methyltetrahydrofolic acid prove less effective. All women will also receive a prenatal multivitamin (not containing folate) to ensure adequacy of other nutrients. Baseline and endline blood samples will be collected to assess primary outcome measures, including serum folate, red blood cell folate and unmetabolized folic acid. The extent to which the change in primary outcomes from baseline to endline differs between treatment groups, controlling for baseline level, will be estimated using linear regression. Participants will have the option to continue supplementing until 1 week postpartum to provide a breastmilk and blood sample. Exploratory analyses will be completed to evaluate breastmilk and postpartum blood folate concentrations. Discussion This proof-of-concept trial is needed to obtain estimates of the effect of (6S)-5-methyltetrahydrofolic acid compared to folic acid on circulating biomarkers of folate status during pregnancy. These estimates will inform the design of a definitive trial which will be powered to assess whether (6S)-5-methyltetrahydrofolic acid is as effective as folic acid in raising blood folate concentrations during pregnancy. Ultimately, these findings will inform folate supplementation policies for pregnant women. Trial registration ClinicalTrials.gov, ID: NCT04022135. Registered on 14 July 2019.
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Affiliation(s)
- Kelsey M Cochrane
- Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, BC, V6T 1Z4, Canada.,BC Children's Hospital Research Institute, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
| | - Chantal Mayer
- Department of Obstetrics and Gynaecology, University of British Columbia, 4500 Oak Street, Vancouver, BC, V6H 3N1, Canada
| | - Angela M Devlin
- BC Children's Hospital Research Institute, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.,Department of Paediatrics, Faculty of Medicine, The University of British Columbia, 4480 Oak Street, Vancouver, BC, V6H 3V4, Canada
| | - Rajavel Elango
- BC Children's Hospital Research Institute, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.,Department of Paediatrics, Faculty of Medicine, The University of British Columbia, 4480 Oak Street, Vancouver, BC, V6H 3V4, Canada.,School of Population and Public Health, Faculty of Medicine, The University of British Columbia, 2206 East Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Jennifer A Hutcheon
- BC Children's Hospital Research Institute, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.,Department of Obstetrics and Gynaecology, University of British Columbia, 4500 Oak Street, Vancouver, BC, V6H 3N1, Canada
| | - Crystal D Karakochuk
- Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, BC, V6T 1Z4, Canada. .,BC Children's Hospital Research Institute, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.
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18
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Is High Folic Acid Intake a Risk Factor for Autism?-A Review. Brain Sci 2017; 7:brainsci7110149. [PMID: 29125540 PMCID: PMC5704156 DOI: 10.3390/brainsci7110149] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 01/29/2023] Open
Abstract
Folate is required for metabolic processes and neural development. Insuring its adequate levels for pregnant women through supplementation of grain-based foods with synthetic folic acid (FA) in order to prevent neural tube defects has been an ongoing public health initiative. However, because women are advised to take multivitamins containing FA before and throughout pregnancy, the supplementation together with natural dietary folates has led to a demographic with high and rising serum levels of unmetabolized FA. This raises concerns about the detrimental effects of high serum synthetic FA, including a rise in risk for autism spectrum disorder (ASD). Some recent studies have reported a protective effect of FA fortification against ASD, but others have concluded there is an increased risk for ASD and other negative neurocognitive development outcomes. These issues are accompanied by further health questions concerning high, unmetabolized FA levels in serum. In this review, we outline the reasons excess FA supplementation is a concern and review the history and effects of supplementation. We then examine the effects of FA on neuronal development from tissue culture experiments, review recent advances in understanding of metabolic functional blocks in causing ASD and treatment for these with alternative forms such as folinic acid, and finally summarize the conflicting epidemiological findings regarding ASD. Based on the evidence evaluated, we conclude that caution regarding over supplementing is warranted.
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Cantarella CD, Ragusa D, Giammanco M, Tosi S. Folate deficiency as predisposing factor for childhood leukaemia: a review of the literature. GENES & NUTRITION 2017; 12:14. [PMID: 28588742 PMCID: PMC5455200 DOI: 10.1186/s12263-017-0560-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/05/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Folic acid and its derivates, known as folates, are chemoprotective micronutrients of great interest because of their essential role in the maintenance of health and genomic integrity. The supplementation of folic acid during pregnancy has long been known to reduce the risk of neural tube defects (NTDs) in the foetus. Folate metabolism can be altered by many factors, including adequate intake through diet. Folate deficiency can compromise the synthesis, repair and methylation of DNA, with deleterious consequences on genomic stability and gene expression. These processes are known to be altered in chronic diseases, including cancer and cardiovascular diseases. MAIN BODY This review focuses on the association between folate intake and the risk of childhood leukaemia. Having compiled and analysed studies from the literature, we show the documented effects of folates on the genome and their role in cancer prevention and progression with particular emphasis on DNA methylation modifications. These changes are of crucial importance during pregnancy, as maternal diet has a profound impact on the metabolic and physiological functions of the foetus and the susceptibility to disease in later life. Folate deficiency is capable of modifying the methylation status of certain genes at birth in both animals and humans, with potential pathogenic and tumorigenic effects on the progeny. Pre-existing genetic polymorphisms can modify the metabolic network of folates and influence the risk of cancer, including childhood leukaemias. The protective effects of folic acid might be dose dependent, as excessive folic acid could have the adverse effect of nourishing certain types of tumours. CONCLUSION Overall, maternal folic acid supplementation before and during pregnancy seems to confer protection against the risk of childhood leukaemia in the offspring. The optimal folic acid requirements and supplementation doses need to be established, especially in conjunction with other vitamins in order to determine the most successful combinations of nutrients to maintain genomic health and wellbeing. Further research is therefore needed to uncover the role of maternal diet as a whole, as it represents a main factor capable of inducing permanent changes in the foetus.
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Affiliation(s)
- Catia Daniela Cantarella
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy
| | - Denise Ragusa
- Division of Biosciences, College of Health and Life Sciences, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UK
| | - Marco Giammanco
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy
| | - Sabrina Tosi
- Division of Biosciences, College of Health and Life Sciences, Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UK
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Wilson RD. Supplémentation préconceptionnelle en acide folique / multivitamines pour la prévention primaire et secondaire des anomalies du tube neural et d'autres anomalies congénitales sensibles à l'acide folique. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2017; 38:S646-S664. [PMID: 28063572 DOI: 10.1016/j.jogc.2016.09.069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIF Offrir des renseignements à jour sur l'utilisation pré et postconceptionnelle d'acide folique par voie orale, avec ou sans supplément de multivitamines / micronutriments, aux fins de la prévention des anomalies du tube neural et d'autres anomalies congénitales. Ces renseignements aideront les médecins, les sages-femmes, les infirmières et les autres professionnels de la santé à contribuer aux efforts de sensibilisation des femmes quant à l'utilisation et aux posologies adéquates de la supplémentation en acide folique / multivitamines, avant et pendant la grossesse. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, Medline, CINAHL et la Cochrane Library en janvier 2011 au moyen d'un vocabulaire contrôlé et de mots clés appropriés (p. ex. « folic acid », « prenatal multivitamins », « folate sensitive birth defects », « congenital anomaly risk reduction », « pre-conception counselling »). Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre 1985 et juin 2014. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en juin 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques, et auprès de sociétés de spécialité médicale nationales et internationales. COûTS, RISQUES ET AVANTAGES: Les coûts financiers sont ceux de la supplémentation quotidienne en vitamines et de la consommation d'un régime alimentaire santé enrichi en folate. Les risques sont ceux qui sont liés à une association signalée entre la supplémentation alimentaire en acide folique et des modifications épigénétiques fœtales / la probabilité accrue d'obtenir une grossesse gémellaire. Ces associations pourraient devoir être prises en considération avant la mise en œuvre d'une supplémentation en acide folique. La supplémentation en acide folique par voie orale (ou l'apport alimentaire en folate combiné à un supplément de multivitamines / micronutriments) a pour avantage de mener à une baisse connexe du taux d'anomalies du tube neural et peut-être même des taux d'autres complications obstétricales et anomalies congénitales particulières. VALEURS La qualité des résultats est évaluée au moyen des critères décrits par le Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). DéCLARATION SOMMAIRE: RECOMMANDATIONS.
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Ahmed T, Fellus I, Gaudet J, MacFarlane AJ, Fontaine-Bisson B, Bainbridge SA. Effect of folic acid on human trophoblast health and function in vitro. Placenta 2015; 37:7-15. [PMID: 26748157 DOI: 10.1016/j.placenta.2015.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/11/2015] [Accepted: 11/24/2015] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The combined intake of folic acid (FA) from prenatal multivitamin supplements and fortified foods can result in FA intake values that exceed the tolerable upper intake level (UL). It is unclear what impact FA intake above the UL may have on the feto-placental unit. Our objective was to determine the effects of increasing concentrations of FA on trophoblast health and function in vitro. METHODS Two human placental cell lines [HTR-8/SVneo (n = 5 experiments) and BeWo (n = 5 experiments)] and human placenta tissue explants (n = 6 experiments) were exposed to increasing concentrations of FA (2-2000 ng/mL) for 48-h. Intracellular total folate concentration, trophoblast proliferation, viability, apoptosis, placenta cell invasion and β-hCG hormone release were assessed. RESULTS Exposure to increasing FA concentrations resulted in higher intracellular total folate in placental cell lines and tissue explants (p < 0.05); yet, only minimal effects of excess folic acid were observed on the primary indicators of placental health and function studied. Specifically, treatment with excess folic acid (2000 ng/mL) resulted in reduced cellular viability in the villous trophoblast BeWo cell line and increased rates of proliferation in the HT8-8/SVneo extravillous trophoblast cell line (p < 0.05). Further, deficient concentrations of folic acid (2 ng/mL) resulted in decreased cell viability and invasive capabilities of the HTR-8/SVneo extravillous trophoblast cell line (p < 0.05). DISCUSSION Our results demonstrate that placental health and function may be compromised in conditions of folate deficiency, and not necessarily in conditions of excess FA. This finding supports the recommendation of prenatal folic acid supplementation in the North American population. Further work aimed at clarifying the therapeutic window of FA intake in the obstetrical population is warranted.
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Affiliation(s)
- Tasfia Ahmed
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, K1N 6N5, Canada.
| | - Ilan Fellus
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, K1N 6N5, Canada.
| | - Jeremiah Gaudet
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, K1N 6N5, Canada.
| | - Amanda J MacFarlane
- Nutrition Research Division, Health Canada, 251 Sir Frederick Banting Driveway, AL2203E, Ottawa, K1A 0K9, Canada.
| | | | - Shannon A Bainbridge
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, K1N 6N5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, K1H 8M5, Canada; Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, K1Y 4E9, Canada.
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22
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Price RJ, Lillycrop KA, Burdge GC. Folic acid supplementation in vitro induces cell type–specific changes in BRCA1 and BRCA 2 mRNA expression, but does not alter DNA methylation of their promoters or DNA repair. Nutr Res 2015; 35:532-44. [DOI: 10.1016/j.nutres.2015.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 04/01/2015] [Accepted: 04/07/2015] [Indexed: 12/31/2022]
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Choi JH, Yates Z, Veysey M, Heo YR, Lucock M. Contemporary issues surrounding folic Acid fortification initiatives. Prev Nutr Food Sci 2014; 19:247-60. [PMID: 25580388 PMCID: PMC4287316 DOI: 10.3746/pnf.2014.19.4.247] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/07/2014] [Indexed: 12/20/2022] Open
Abstract
The impact of folate on health and disease, particularly pregnancy complications and congenital malformations, has been extensively studied. Mandatory folic acid fortification therefore has been implemented in multiple countries, resulting in a reduction in the occurrence of neural tube defects. However, emerging evidence suggests increased folate intake may also be associated with unexpected adverse effects. This literature review focuses on contemporary issues of concern, and possible underlying mechanisms as well as giving consideration the future direction of mandatory folic acid fortification. Folate fortification has been associated with the presence of unmetabolized folic acid (PteGlu) in blood, masking of vitamin B12 deficiency, increased dosage for anti-cancer medication, photo-catalysis of PteGlu leading to potential genotoxicity, and a role in the pathoaetiology of colorectal cancer. Increased folate intake has also been associated with twin birth and insulin resistance in offspring, and altered epigenetic mechanisms of inheritance. Although limited data exists to elucidate potential mechanisms underlying these issues, elevated blood folate level due to the excess use of PteGlu without consideration of an individual's specific phenotypic traits (e.g. genetic background and undiagnosed disease) may be relevant. Additionally, the accumulation of unmetabolized PteGlu may lead to inhibition of dihydrofolate reductase and other enzymes. Concerns notwithstanding, folic acid fortification has achieved enormous advances in public health. It therefore seems prudent to target and carefully monitor high risk groups, and to conduct well focused further research to better understand and to minimize any risk of mandatory folic acid fortification.
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Affiliation(s)
- Jeong-Hwa Choi
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia
- Human Economics Research Institute, Chonnam National University, Gwangju 500-757, Korea
| | - Zoe Yates
- Biomedical Sciences and Pharmacy, University of Newcastle, Ourimbah, NSW 2258, Australia
| | - Martin Veysey
- Teaching and Research Unit, Central Coast Local Health District, Gosford, NSW 2250, Australia
| | - Young-Ran Heo
- Department of Food and Nutrition, Chonnam National University, Gwangju 500-757, Korea
| | - Mark Lucock
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia
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Folic acid supplementation and preterm birth: results from observational studies. BIOMED RESEARCH INTERNATIONAL 2014; 2014:481914. [PMID: 24724083 PMCID: PMC3958780 DOI: 10.1155/2014/481914] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/01/2014] [Accepted: 01/01/2014] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Folic acid (FA) supplementation is recommended worldwide in the periconceptional period for the prevention of neural tube defects. Due to its involvement in a number of cellular processes, its role in other pregnancy outcomes such as miscarriage, recurrent miscarriage, low birth weight, preterm birth (PTB), preeclampsia, abruptio placentae, and stillbirth has been investigated. PTB is a leading cause of perinatal mortality and morbidity; therefore its association with FA supplementation is of major interest. The analysis of a small number of randomized clinical trials (RCTs) has not found a beneficial role of FA in reducing the rate of PTBs. AIM OF THE STUDY The aim of this review was to examine the results from recent observational studies about the effect of FA supplementation on PTB. MATERIALS AND METHODS We carried out a search on Medline and by manual search of the observational studies from 2009 onwards that analyzed the rate of PTB in patients who received supplementation with FA before and/or throughout pregnancy. RESULTS The results from recent observational studies suggest a slight reduction of PTBs that is not consistent with the results from RCTs. Further research is needed to better understand the role of FA supplementation before and during pregnancy in PTB.
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