Pharmacokinetics of (6S)-5-Methyltetrahydrofolate dicholine salt compared to folic acid: a randomized double-blind single dose cross-over study

Christiane Schön; Antje Micka; Daniel Menzel; Manfred Wilhelm; Rima Obeid

doi:10.29219/fnr.v69.12633

Christiane Schön BioTeSys GmbH, Esslingen, Germany
Antje Micka BioTeSys GmbH, Esslingen, Germany
Daniel Menzel BioTeSys GmbH, Esslingen, Germany
Manfred Wilhelm Department of Mathematics, Natural and Economic Sciences, Ulm University of Applied Sciences, Ulm, Germany
Rima Obeid Department of Clinical Chemistry and Laboratory Medicine, University Hospital of the Saarland, Homburg, Germany

DOI: https://doi.org/10.29219/fnr.v69.12633

Keywords: Optifolin ®, (6S)-5-MethylTHF-2-choline, (6S)-5-MethylTHF, folic acid; bioavailability

Abstract

Background: (6S)-5-Methyltetrahydrofolate ((6S)-5-MethylTHF) is the physiological folate form in biological fluids. Salts of (6S)-5-MethylTHF may have advantages compared to folic acid and are increasingly used in foods and supplements.

Objective and design: The present study describes the physicochemical properties of the (6S)-5-MethylTHF-2Chol salt as a source of methylfolate with respect to solubility, conductivity, and melting point. The pharmacokinetics of (6S)-5-MethylTHF-2Chol and folic acid were compared in a randomized controlled double-blind cross-over study using a single equimolar oral dose of each of the folate substances.

Results: The solubility of the dicholine salt was very high (650 mg/mL in H₂O and 40 mg/mL in H₂O under acidic conditions). The incremental area under the curve (iAUC_0-8h) was significantly higher after the administration of (6S)-5-MethylTHF-2Chol compared to folic acid ([1.64-fold, P < 0.0001] for total folate and 2.56-fold higher for (6S)-5-MethylTHF [P < 0.0001]).

Discussion and conclusions: The bioavailability of (6S)-5-MethylTHF-2Chol is higher compared to folic acid. The crystalline structure of (6S)-5-MethylTHF-2Chol and its water solubility are advantageous in terms of stability in nutraceutical products and absorption in the gut. (6S)-5-MethylTHF-2Chol is the source of folate that may enable the development of new applications.

Downloads

Download data is not yet available.

References

1.
Wusigale, Liang L. Folates: stability and interaction with biological molecules. J Agric Food Res 2020; 2: 100039. doi: 10.1016/j.jafr.2020.100039

2.
McKillop DJ, McNulty H, Scott JM, McPartlin JM, Strain JJ, Bradbury I, et al. The rate of intestinal absorption of natural food folates is not related to the extent of folate conjugation. Am J Clin Nutr 2006; 84: 167–73. doi: 10.1093/ajcn/84.1.167

3.
Wei MM, Bailey LB, Toth JP, Gregory JF. Bioavailability for humans of deuterium-labeled monoglutamyl and polyglutamyl folates is affected by selected foods. J Nutr 1996; 126: 3100–8. doi: 10.1093/jn/126.12.3100

4.
Institute of Medicine. Dietary reference intakes: applications in dietary assessment. Washington (DC): National Academies Press; 2000.

5.
Aweke MN, Fentie EA, Agimas MC, Baffa LD, Shewarega ES, Belew AK, et al. Folic acid supplementation during preconception period in sub-Saharan African countries: a systematic review and meta-analysis. PLoS One 2025; 20: e0318422. doi: 10.1371/journal.pone.0318422

6.
Yadav U, Kumar P, Rai V. Maternal biomarkers for early prediction of the neural tube defects pregnancies. Birth Defects Res 2021; 113: 589–600. doi: 10.1002/bdr2.1842

7.
U.S. Preventive Services Task Force. Folic acid for the prevention of neural tube defects: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2009; 150: 626–31. doi: 10.7326/0003-4819-150-9-200905050-00009

8.
Fothergill A, Crider KS, Rose CE, Bose B, Guetterman HM, Johnson CB, et al. Estimating the serum folate concentration that corresponds to the red blood cell folate concentration threshold associated with optimal neural tube defects prevention: a population-based biomarker survey in Southern India. Am J Clin Nutr 2023; 117: 985–97. doi: 10.1016/j.ajcnut.2023.01.016

9.
Obeid R, Rube E, Schön C, Geisel J. Serum concentrations of folate forms following supplementation of multimicronutrients with 400 μg or 800 μg Mix of (6S)-5-methyltetrahydrofolate and folic acid (1:1) in women of childbearing age. Mol Nutr Food Res 2024; 68: e2400444. doi: 10.1002/mnfr.202400444

10.
Masih SP, Plumptre L, Ly A, Berger H, Lausman AY, Croxford R, et al. Pregnant Canadian women achieve recommended intakes of one-carbon nutrients through prenatal supplementation but the supplement composition, including choline, requires reconsideration. J Nutr 2015; 145: 1824–34. doi: 10.3945/jn.115.211300

11.
Institute of Medicine. Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline: Chapter 8 Folate. Washington, DC: National Academies Press; 2000.

12.
Sweeney MR, McPartlin J, Scott J. Folic acid fortification and public health: report on threshold doses above which unmetabolised folic acid appear in serum. BMC Public Health 2007; 7: 41. doi: 10.1186/1471-2458-7-41

13.
Johnson WG, Stenroos ES, Spychala JR, Chatkupt S, Ming SX, Buyske S. New 19 bp deletion polymorphism in intron-1 of dihydrofolate reductase (DHFR): a risk factor for spina bifida acting in mothers during pregnancy? Am J Med Genet A 2004; 124A: 339–45. doi: 10.1002/ajmg.a.20505

14.
Cochrane KM, Elango R, Devlin AM, Mayer C, Hutcheon JA, Karakochuk CD. Supplementation with (6S)-5-methyltetrahydrofolic acid appears as effective as folic acid in maintaining maternal folate status while reducing unmetabolised folic acid in maternal plasma: a randomised trial of pregnant women in Canada. Br J Nutr 2024; 131: 92–102. doi: 10.1017/S0007114523001733

15.
Scaglione F, Panzavolta G. Folate, folic acid and 5-methyltetrahydrofolate are not the same thing. Xenobiotica 2014; 44: 480–8. doi: 10.3109/00498254.2013.845705

16.
Saldanha LG, Dwyer JT, Haggans CJ, Mills JL, Potischman N. Perspective: time to resolve confusion on folate amounts, units, and forms in prenatal supplements. Adv Nutr 2020; 11: 753–9. doi: 10.1093/advances/nmaa017

17.
Pfeiffer CM, Sternberg MR, Fazili Z, Yetley EA, Lacher DA, Bailey RL, et al. Unmetabolized folic acid is detected in nearly all serum samples from US children, adolescents, and adults. J Nutr 2015; 145: 520–31. doi: 10.3945/jn.114.201210

18.
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. doi: 10.1038/s41598-023-38224-4

19.
Obeid R, Kasoha M, Kirsch SH, Munz W, Herrmann W. Concentrations of unmetabolized folic acid and primary folate forms in pregnant women at delivery and in umbilical cord blood. Am J Clin Nutr 2010; 92: 1416–22. doi: 10.3945/ajcn.2010.29361

20.
Turck D, Bohn T, Castenmiller J, de Henauw S, Hirsch-Ernst KI, Knutsen HK, et al. Conversion of calcium-l-methylfolate and (6S)-5-methyltetrahydrofolic acid glucosamine salt into dietary folate equivalents. EFS2 2022; 20: e07452. doi: 10.2903/j.efsa.2022.7452

21.
Obeid R, Schön C, Pietrzik K, Menzel D, Wilhelm M, Smulders Y, et al. Pharmacokinetics of sodium and calcium salts of (6S)-5-methyltetrahydrofolic acid compared to folic acid and indirect comparison of the two salts. Nutrients 2020; 12(12): 3623. doi: 10.3390/nu12123623

22.
Ueland PM. Choline and betaine in health and disease. J Inherit Metab Dis 2011; 34: 3–15. doi: 10.1007/s10545-010-9088-4

23.
OECD (Organisation for Economic Co-operation and Development). Test No. 105: Water Solubility, OECD Guidelines for the Testing of Chemicals, Section 1. Paris: OECD Publishing; 1995. doi: 10.1787/9789264069589-en

24.
Kirsch SH, Knapp J-P, Herrmann W, Obeid R. Quantification of key folate forms in serum using stable-isotope dilution ultra performance liquid chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878: 68–75. doi: 10.1016/j.jchromb.2009.11.021

25.
Gazzali AM, Lobry M, Colombeau L, Acherar S, Azaïs H, Mordon S, et al. Stability of folic acid under several parameters. Eur J Pharm Sci 2016; 93: 419–30. doi: 10.1016/j.ejps.2016.08.045

26.
Bottari E, D’Ambrosio A, de Tommaso G, Festa MR, Iuliano M, Meschino M. Solubility of folic acid and protonation of folate in NaCl at different concentrations, even in physiological solution. Analyst 2021; 146: 2339–47. doi: 10.1039/D1AN00013F

27.
Dressler D, Engelhart-Jentzsch K, Lambert C. Skin penetration of active folate salts and their effects on wound healing in vitro: new approaches for dermal folate application. hb TIMES Schw Aertzej 2023;8: 62–9. doi: 10.36000/hbT.2023.09.002

28.
Prinz-Langenohl R, Brämswig S, Tobolski O, Smulders YM, Smith DE, Finglas PM, et al. 6S-5-methyltetrahydrofolate increases plasma folate more effectively than folic acid in women with the homozygous or wild-type 677C→T polymorphism of methylenetetrahydrofolate reductase. Br J Pharmacol 2009;158: 2014–21. doi: 10.1111/j.1476-5381.2009.00492.x

29.
Pentieva K, McNulty H, Reichert R, Ward M, Strain JJ, McKillop DJ, et al. The short-term bioavailabilities of [6S]-5-methyltetrahydrofolate and folic acid are equivalent in men. J Nutr 2004; 134: 580–5. doi: 10.1093/jn/134.3.580

30.
Visentin M, Diop-Bove N, Zhao R, Goldman ID. The intestinal absorption of folates. Annu Rev Physiol 2014; 76: 251–74. doi: 10.1146/annurev-physiol-020911-153251

31.
Farrell CC, Khanna S, Hoque MT, Plaga A, Basset N, Syed I, et al. Low-dose daily folic acid (400 μg) supplementation does not affect regulation of folate transporters found present throughout the terminal ileum and colon of humans: a randomized clinical trial. Am J Clin Nutr 2024; 119: 809–20. doi: 10.1016/j.ajcnut.2023.12.018

32.
Venn BJ, Green TJ, Moser R, McKenzie JE, Skeaff CM, Mann J. Increases in blood folate indices are similar in women of childbearing age supplemented with 6S-5-methyltetrahydrofolate and folic acid. J Nutr 2002; 132: 3353–5. doi: 10.1093/jn/132.11.3353

33.
Venn BJ, Green TJ, Moser R, Mann JI. Comparison of the effect of low-dose supplementation with L-5-methyltetrahydrofolate or folic acid on plasma homocysteine: a randomized placebo-controlled study. Am J Clin Nutr 2003; 77: 658–62. doi: 10.1093/ajcn/77.3.658

34.
Lamers Y, Prinz-Langenohl R, Brämswig S, Pietrzik K. Red blood cell folate concentrations increase more after supplementation with 6S-5-methyltetrahydrofolate than with folic acid in women of childbearing age. Am J Clin Nutr 2006;84: 156–61. doi: 10.1093/ajcn/84.1.156

35.
Green TJ, Liu Y, Dadgar S, Li W, Böhni R, Kitts DD. Wheat rolls fortified with microencapsulated L-5-methyltetrahydrofolic acid or equimolar folic acid increase blood folate concentrations to a similar extent in healthy men and women. J Nutr 2013; 143: 867–71. doi: 10.3945/jn.113.174268

36.
Kelly P, McPartlin J, Goggins M, Weir DG, Scott JM. Unmetabolized folic acid in serum: acute studies in subjects consuming fortified food and supplements. Am J Clin Nutr 1997; 65: 1790–5. doi: 10.1093/ajcn/65.6.1790

37.
Harlan De Crescenzo A, Panoutsopoulos AA, Tat L, Schaaf Z, Racherla S, et al. Deficient or excess folic acid supply during pregnancy alter cortical neurodevelopment in mouse offspring. Cereb Cortex 2021; 31: 635–49. doi: 10.1093/cercor/bhaa248

38.
Selhub J, Rosenberg IH. Excessive folic acid intake and relation to adverse health outcome. Biochimie 2016; 126: 71–8. doi: 10.1016/j.biochi.2016.04.010

39.
Cao X, Xu J, Lin YL, Cabrera RM, Chen Q, Zhang C, et al. Excess folic acid intake increases DNA de novo point mutations. Cell Discov 2023; 9(1): 22. doi: 10.1038/s41421-022-00512-0

40.
Maruvada P, Stover PJ, Mason JB, Bailey RL, Davis CD, Field MS, et al. Knowledge gaps in understanding the metabolic and clinical effects of excess folates/folic acid: a summary, and perspectives, from an NIH workshop. Am J Clin Nutr 2020; 112: 1390–403. doi: 10.1093/ajcn/nqaa259

41.
Christensen KE, Mikael LG, Leung K-Y, Lévesque N, Deng L, Wu Q, et al. High folic acid consumption leads to pseudo-MTHFR deficiency, altered lipid metabolism, and liver injury in mice12345. Am J Clin Nutr 2015; 101: 646–58. doi: 10.3945/ajcn.114.086603

42.
Mikael LG, Deng L, Paul L, Selhub J, Rozen R. Moderately high intake of folic acid has a negative impact on mouse embryonic development. Birth Defects Res A Clin Mol Teratol 2013; 97: 47–52. doi: 10.1002/bdra.23092

43.
Bailey SW, Ayling JE. The extremely slow and variable activity of dihydrofolate reductase in human liver and its implications for high folic acid intake. Proc Natl Acad Sci U S A 2009; 106: 15424–9. doi: 10.1073/pnas.0902072106

44.
Ledowsky C, Mahimbo A, Scarf V, Steel A. Women taking a folic acid supplement in countries with mandatory food fortification programs may be exceeding the upper tolerable limit of folic acid: a systematic review. Nutrients 2022; 14(13): 2715. doi: 10.3390/nu14132715

45.
Bailey RL, Pac SG, Fulgoni VL 3rd, Reidy KC, Catalano PM. Estimation of total usual dietary intakes of pregnant women in the United States. JAMA Netw Open 2019; 2(6): e195967. doi: 10.1001/jamanetworkopen.2019.5967

Pharmacokinetics of (6S)-5-Methyltetrahydrofolate dicholine salt compared to folic acid: a randomized double-blind single dose cross-over study

Abstract

Downloads

References

Most read articles by the same author(s)