Biomarkers of carotenoid bioavailability

Area of Science:

• Nutritional Biochemistry
• Human Physiology

Background:

• Biomarkers are crucial for assessing carotenoid bioavailability in humans.
• Carotenoids, including carotenes and xanthophylls, exhibit varied absorption and tissue accumulation.
• Dietary carotenoids can undergo chemical modifications, forming metabolites and apocarotenoids.

Purpose of the Study:

• To review methodological, host-related, and modulating factors influencing carotenoid bioavailability assessment.
• To differentiate between direct (analytical) and indirect (functional) biomarkers.
• To discuss the variability and interpretation of biological responses to carotenoid interventions.

Main Methods:

• Review of existing literature on carotenoid bioavailability markers.
• Categorization of biomarkers into analytical (biochemical) and functional (physiological) indicators.
• Analysis of factors affecting marker interpretation, including specimen type and time frame.

Main Results:

• Analytical markers indicate intake/status; functional markers reflect bioactivity and risk modification.
• Carotenoid absorption and systemic profiles differ among various classes.
• High doses and long-term interventions can lead to saturation and non-linear responses.
• Overexposure markers include carotenodermia, corneal rings, retinopathy, hypercarotenemia, and xanthophyll esters.

Conclusions:

• Host-related and methodological factors significantly impact carotenoid bioavailability markers.
• Different carotenoid subclasses may be affected unequally by these factors.
• Accurate interpretation requires consideration of marker type, biological specimen, and intervention protocol.