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

Not Applicable

Completed

• Conditions: Healthy

• Registration Number: NCT00128752
• Lead Sponsor: Radboud University Medical Center

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2003-03
• Study Completion: 2003-10
• Status Verified: 2005-08
• Study First Submitted: 2005-08-09
• Study First Submitted QC: 2005-08-09
• Study First Posted: 2005-08-10
• Last Update Submitted: 2005-08-26
• Last Update Posted: 2005-08-29

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 24

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
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

Trial Locations

Locations (1)

Radboud University Nijmegen Medical Centre; 🇳🇱 Nijmegen, Gelderland, Netherlands