INTESTINAL BETA-CAROTENE ABSORPTION AND CLEAVAGE IN MEN - RESPONSE OFBETA-CAROTENE AND RETINYL ESTERS IN THE TRIGLYCERIDE-RICH LIPOPROTEINFRACTION AFTER A SINGLE ORAL DOSE OF BETA-CAROTENE

Postprandial response curves of beta-carotene and retinyl esters in a triglyceride-rich lipoprotein (TRL) fraction were evaluated as a poten tial measure of beta-carotene uptake and cleavage. beta-Carotene, reti nyl ester, and triglyceride concentrations in the TRL fraction (densit y < 1.006 kg/L) and plasma were measured in 10 men for 8 or 16 h after an oral dose of 15 mg beta-carotene. The beta-carotene response, unli ke the triglyceride and retinyl ester response, can be evaluated in th e TRL fraction but not in plasma. Intraindividual variations in the tr iglyceride-adjusted response of beta-carotene and retinyl palmitate in TRL fractions were 23% and 20% and interindividual variations were 42 % and 36%, respectively. A low beta-carotene response was associated w ith a high ratio between retinyl palmitate and beta-carotene responses (r = -0.56, P = 0.013). in conclusion, the measurement of beta-carote ne and retinyl esters in the TRL fraction after a dose of beta-caroten e with a vitamin A-free meal may be an appropriate method to study bet a-carotene uptake and cleavage.