Bioavailability and vitamin A value of carotenes from red palm oil assessed by an extrinsic isotope reference method

Authors:
Publisher website
Google Scholar
Abstract
Red palm oil (RPO) contains high concentrations of β‐ and α‐carotene, and is presumed to possess a higher vitamin A value than other foods. The objective was to determine the metabolic vitamin A and carotene values of refined red palm oil in healthy adult subjects, using a stable isotope reference method. Twelve healthy subjects were administered a small standardised meal containing 10 g RPO (2.4 mg β‐carotene and 1.8 mg α‐carotene) in a blended juice‐based drink also containing 2 mg tetradeuterated retinyl acetate (d4‐RA) as a metabolic reference. At baseline and at several times after the test meal, the concentrations of carotenes and of d4‐ and d0‐(unlabelled) retinyl esters, in the plasma chylomicron‐rich (d < 1.006) fraction were determined by high high‐performance liquid chromatography and gas chromatography mass spectrometry, respectively. The masses of palm oil‐derived vitamin A and carotenes absorbed (‘yield’) were calculated assuming 80% absorption of the d4‐RA reference dose. The mean yield of retinol from the RPO was 0.41 mg, ranging from 0.17 mg to 0.86 mg. The mean yields of β‐ and α‐carotene were 0.29 mg and 0.25 mg, respectively, suggesting that β‐carotene was more extensively metabolised than α‐carotene. Subjects assimilated an average of 23% of the dose of carotenes, as the sum of retinol and unmetabolised carotenes. The vitamin A values of red palm oil obtained under these conditions, a mean of 0.17 mg retinol absorbed per mg β‐carotene consumed (β‐carotene : retinol equivalency of 5.7:1) is higher than that of all other vegetable sources we have evaluated to date.

This publication has 20 references indexed in Scilit: