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Where is the Initial Site of Biotransformation of Folates in Humans? (FOLTIPS)

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ClinicalTrials.gov Identifier: NCT02135393
Recruitment Status : Completed
First Posted : May 9, 2014
Last Update Posted : May 9, 2014
Sponsor:
Collaborators:
Quadram Institute Bioscience
University of Nottingham
Information provided by (Responsible Party):
Newcastle-upon-Tyne Hospitals NHS Trust

Brief Summary:
The aim of this study is to test the assumption that, in humans, folic acid, a dietary supplement is biotransformed (reduced and methylated) to the natural circulating plasma folate 6S-5Methyltetrahydrofolic acid (5-MTHF) in the intestinal mucosa.

Condition or disease Intervention/treatment Phase
Healthy Dietary Supplement: 13C5-folic acid or 13C5-6S-5-FormylTHF Not Applicable

Detailed Description:

Current thinking, based mainly on rodent studies, is that physiological doses of folic acid (pteroylmonoglutamic acid), like dietary vitamin folates, are biotransformed in the intestinal mucosa and transferred to the portal vein as the natural circulating plasma folate, 5-methyltetrahydrofolic acid (5-MTHF), before entering the liver and the wider systemic blood supply.

Study design:Open labelled study that samples portal and peripheral veins for labelled folate concentrations following oral ingestion with physiological doses of dietary supplements stable-isotope-labelled folic acid, or, the reduced folate, 5-formyltetrahydrofolic acid (5-FormylTHF). The study was performed in subjects with a Transjugular Intrahepatic Porto Systemic Shunt (TIPSS) in situ at the time of a routine annual patency check to allow blood samples to be taken from the portal vein. The aim of this study is to test the assumption that, in humans, folic acid is biotransformed (reduced and methylated) to 5-MTHF in the intestinal mucosa.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 6 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Folic Acid Handling by the Human Gut: Implications for Food Fortification and Supplementation
Study Start Date : April 2009
Actual Primary Completion Date : September 2011
Actual Study Completion Date : September 2011

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: 13C5-folic acid or 13C5-6S-5-FormylTHF
Physiological 500 nmol (220 µg folic acid equivalent) dose of dietary supplement 13C5-folic acid or 13C5-6S-5-FormylTHF given to subjects with in situ transjugular intrahepatic portosystemic stent at the time of routine venography patency check followed by regular portal venous sampling for 85 minutes at pre determined intervals and then physiological 500 nmol dose of 13C-6S-5-FormylTHF or 13C5-folic acid respectively at the next annual routine venography patency check followed by portal venous sampling for 85 minutes
Dietary Supplement: 13C5-folic acid or 13C5-6S-5-FormylTHF
Subjects with an insitu transjugular intrahepatic porto systemic stent shunt assigned to receive either a physiological 500 nmol (220 µg folic acid equivalent) dose of 13C5-folic acid or 13C5-6S-5-FormylTHF at the time of routine shunt venography to check patency followed by portal venous sampling at pre defined time points for 85 minutes and then given 13C5-6S-5-FormylTHF ator 13C5-folic acid at their next annual venography patency check with portal venous sampling at pre defined time points for 85 minutes




Primary Outcome Measures :
  1. The percentage of folate in un-modified and modified form in the portal vein for each of the different oral folate dosing formulations [ Time Frame: 85 minutes ]


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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Stable, synthetic liver function without recent evidence of decompensation (defined as liver function inadequacy or active complications of portal hypertension)
  • Abstinent from alcohol
  • Free from malignant disease
  • Normal gut permeability (as assessed by the lactulose/mannitol test)
  • Patent TIPSS on their last surveillance

Exclusion Criteria:

  • Taking Vitamin B supplements
  • Taking Folic Acid supplementation
  • Unable to provide informed consent

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02135393


Locations
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United Kingdom
Freeman Hospital
Newcastle Upon Tyne, Tyneside, United Kingdom, NE7 7DN
Institute of Food Research
Norwich, United Kingdom, NR47UA
Sponsors and Collaborators
Newcastle-upon-Tyne Hospitals NHS Trust
Quadram Institute Bioscience
University of Nottingham
Investigators
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Principal Investigator: David E Jones, PhD FRCP Newcastle University
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Newcastle-upon-Tyne Hospitals NHS Trust
ClinicalTrials.gov Identifier: NCT02135393    
Other Study ID Numbers: UK CRN 5085
First Posted: May 9, 2014    Key Record Dates
Last Update Posted: May 9, 2014
Last Verified: May 2014
Additional relevant MeSH terms:
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Folic Acid
Hematinics
Vitamin B Complex
Vitamins
Micronutrients
Nutrients
Growth Substances
Physiological Effects of Drugs