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

May 8, 2014 updated by: Newcastle-upon-Tyne Hospitals NHS Trust

Folic Acid Handling by the Human Gut: Implications for Food Fortification and Supplementation

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

6

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
      • Norwich, United Kingdom, NR47UA
        • Institute of Food Research
    • Tyneside
      • Newcastle Upon Tyne, Tyneside, United Kingdom, NE7 7DN
        • Freeman Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
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
85 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Newcastle-upon-Tyne Hospitals NHS Trust

Collaborators

University of Nottingham
Quadram Institute Bioscience

Investigators

  • Principal Investigator: David E Jones, PhD FRCP, Newcastle University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2009

Primary Completion (Actual)

September 1, 2011

Study Completion (Actual)

September 1, 2011

Study Registration Dates

First Submitted

May 8, 2014

First Submitted That Met QC Criteria

May 8, 2014

First Posted (Estimate)

May 9, 2014

Study Record Updates

Last Update Posted (Estimate)

May 9, 2014

Last Update Submitted That Met QC Criteria

May 8, 2014

Last Verified

May 1, 2014

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UK CRN 5085

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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