Provitamin A Absorption and Conversion With Avocados

Enhancing Human Intestinal Absorption of Carotenoids and Bioconversion of Carotene to Vitamin A in the Presence of Hass Avocados

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01432210

Enrollment

Registered

2011-09-12

Start date

2011-09-30

Completion date

2012-03-31

Last updated

2016-09-30

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

post-prandial absorption, provitamin A carotenoids, vitamin A, avocado, tomato, carrot

Brief summary

Vitamin A is necessary in the human diet. The form of vitamin A found in fruits and vegetables is not active and must be converted to the active form in the human body. However, information on the ability of humans to absorb and convert vitamin A to the active form is still lacking. In this study, the investigators will observe the absorption and conversion of vitamin A from orange tomato sauce and/or carrots after a meal with fat (from avocado fruit) and a meal without fat. The investigators will also test whether eating these foods might protect the blood against damage that could lead to heart disease.

Detailed description

The primary objective of this study will be to demonstrate that adding avocados to a carotene rich meal will promote the absorption of provitamin A carotenoids and enhance the delivery of greater quantities of vitamin A. This objective will be accomplished by quantitation of the immediate post-prandial plasma concentrations of parent carotenoids and vitamin A metabolites after subjects consume a meal with or without avocado in combination with a serving of tomato sauce (containing nutritionally relevant amounts of beta-carotene) or carrots. The secondary objective of this study will be to determine if higher levels of carotenoids and other antioxidants transported in the bloodstream will have a protective role in promoting cardiovascular health. This objective will be accomplished by testing the oxidation capacity of lipoprotein fractions before and after meal supplementation.

Interventions

OTHERPost-prandial Feeding Study

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 70 Years

Healthy volunteers

Yes

Inclusion criteria

* Total cholesterol (140 to 200 mg/dL) * BMI 17 to 30 * Age 18-70 years

Exclusion criteria

* Lactating, pregnant, or plan to be pregnant during study * Tobacco use (cigarettes or chewing tobacco) * Metabolic disease * Malabsorption disorders * History of cancer, esophageal, gastric, or intestinal ulcers * History of liver or kidney insufficiency or failure * Allergies to tomatoes or tomato products * Allergies to carrots * Allergies to avocados * Obesity (BMI\>30) * Hypercholesterolemia (total cholesterol\> 200mg/dL)

Design outcomes

Primary

Measure	Time frame	Description
Post-prandial levels of provitamin A and vitamin A	Nine post-prandial blood samples will be taken over twelve hours	The absorption of and conversion of provitamin A carotenoids into vitamin A will be measured after the consumption of a carotenoid-rich meal. The meal will be served both with and without avocado as a source of lipid.

Secondary

Measure	Time frame	Description
post-prandial antioxidant status of blood	comparing baseline vs. 5 hour status	The ability of a carotenoid-rich meal to reduce the susceptibility of blood lipoproteins to oxidative stress will be tested. A modified trolox equivalent antioxidant capacity (TEAC) assay will be used.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 20, 2026