The CARO Study - Bioefficacy of Beta-Carotene in Oil and in a Mixed Diet in Healthy Subjects

August 26, 2005 updated by: Radboud University Medical Center

Bioefficacy and Bioavailability of Beta-Carotene in Oil and in a Mixed Diet in Healthy Subjects Measured Using Specifically 13C-Labelled Beta-Carotene and Retinol

A controlled dietary intervention study will be carried out based on the stable isotope method the investigators have developed to quantify both the absorption of beta-carotene and its bioconversion to retinol in oil and in a mixed diet. For 6 weeks the participants will consume 2 capsules/day, 7 days/week with each capsule containing 50-mg [13C10] beta-carotene and 50-mg [13C10] retinyl palmitate. For three weeks they will consume a diet with high levels of beta-carotene in vegetables and fruits and for the other 3 weeks they will consume a diet with low levels of beta-carotene in vegetables and fruits supplemented with an extra amount of beta-carotene in oil. Samples of blood and faeces will be taken.

The study hypothesis is that the absorption of beta-carotene in oil in comparison with the absorption of beta-carotene in a mixed diet differs by a factor of 3 to 6. The investigators want to measure the influence of the food matrix of vegetables and fruits on the absorption of beta-carotene in healthy humans on a western diet.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment

24

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

  • Netherlands
    • Gelderland
      • Nijmegen, Gelderland, Netherlands, 6500HB
        • Radboud University Nijmegen Medical Centre

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

18 years to 50 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Men and women between 18 and 50 years old
  • Body mass index (BMI) between 18 and 25 kg/m2
  • Willing to consume the controlled diet and not consume other food items
  • Willing to consume the cooked meal at the research facility and the bread meals and snacks at home (distributed to the participants)
  • Willing to consume the capsules every day

Exclusion Criteria:

  • Hematological diseases and chronic diseases including cancer, renal insufficiency, liver disease, diagnosed gastrointestinal disorders, or surgery of the gastrointestinal tract
  • Use of (oral) drugs suspected of interfering with fat-soluble-vitamin absorption
  • Smoking
  • Excessive alcohol consumption (>30 g/d)
  • Consumption of vitamin or carotenoid supplements 6 weeks before and during the study
  • Not too low or high levels of serum beta-carotene and retinol
  • Normal hemoglobin, hemocytometry, creatinine, ALAT, alkaline phosphatase, and cholesterol blood values (compared with laboratory references)
  • Pregnancy

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
levels of retinol and carotenoids and the degree of isotopic enrichment in serum (fasting blood sample) and in faeces (72 hour collection) at the start and at the end of each of the 3-week periods

Collaborators and Investigators

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

Sponsor

Radboud University Medical Center

Collaborators

Dutch Dairy Organization (NZO)

Investigators

  • Study Director: Ton HJ Naber, MD PhD, Radboud University Medical Center
  • Principal Investigator: Clive E West, PhD DSc, Radboud University Medical Center
  • Study Chair: Carolien A Bouwman, MSc, Radboud University Medical Center

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

March 1, 2003

Study Completion

October 1, 2003

Study Registration Dates

First Submitted

August 9, 2005

First Submitted That Met QC Criteria

August 9, 2005

First Posted (Estimate)

August 10, 2005

Study Record Updates

Last Update Posted (Estimate)

August 29, 2005

Last Update Submitted That Met QC Criteria

August 26, 2005

Last Verified

August 1, 2005

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CARO-2002-12-12-NZO
  • NZO-2002-07

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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