ArticleJIMD reports2022
Folic acid inhibits 5-methyltetrahydrofolate transport across the blood-cerebrospinal fluid barrier: Clinical biochemical data from two cases.
Article in JIMD reports, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.
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Who cites it
6 citing papers in PubMed.
- Folate Receptor Alpha (FRα) and the Developing Brain: From Molecular Function to Neurodevelopmental Outcomes.Molecular neurobiology · 2026Review
- Fortification, folate and vitamin B12 balance, and the nervous system. Is folic acid excess potentially harmful?European journal of clinical nutrition · 2025Review
- Fortification with folic acid and early human embryo development: lessons from assisted reproduction.Journal of assisted reproduction and genetics · 2025Article
- Article
- Excess Folic Acid Exposure Increases Uracil Misincorporation into DNA in a Tissue-Specific Manner in a Mouse Model of Reduced Methionine Synthase Expression.The Journal of nutrition · 2024Article
- Folic acid inhibits 5-methyltetrahydrofolate transport across the blood-cerebrospinal fluid barrier: Clinical biochemical data from two cases.JIMD reports · 2022Article
Corrections and comments
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Authors and funding
9 authors.
Funding
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Abstract
Objective: The use of folic acid (FA) has been discouraged in cerebral folate deficiency (CFD) because, theoretically, it could inhibit the transport of 5-methyltetrahydrofolic acid (5MTHF) across the blood-cerebrospinal fluid (CSF) barrier. We present the clinical biochemical data of two cases with CFD to support this hypothesis. Methods: We measured CSF and serum 5MTHF concentrations in a patient with Kearns-Sayre syndrome (KSS) and a patient homozygous for Results: Both patients had low CSF 5MTHF before treatment and high-dose FA therapy did not normalize CSF 5MTHF. There was a dissociation between serum total folate and 5MTHF concentrations during FA therapy, which was considered to be due to the appearance of unmetabolized FA. The addition of folinic acid did not improve low CSF 5MTHF in the KSS patient and the cessation of FA resulted in the normalization of CSF 5MTHF. In the patient homozygous for Conclusions: Our data suggest that excess supplementation of FA impaired 5MTHF transport across the blood-CSF barrier. In the treatment of CFD, supplementation of folinic acid or 5MTHF (in cases of impaired 5MTHF synthesis) is preferred over the use of FA. The reference values of CSF 5MTHF concentration based on 600 pediatric cases were also provided.
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