β-Carotene–vitamin A equivalence in Chinese adults assessed by an isotope dilution technique

Abstract

The present study was carried out to determine the conversion factor of synthetic 2H-labelled 60 years were recruited for a 55 d experiment. The volunteers (nine males and six females) were each given a physiological dose of [2H8]-Carotene and retinol were extracted from serum and isolated by HPLC, and their enrichments were respectively determined by using GCatmospheric pressure chemical ionisation interface-MS. Four of the subjects exhibited 0:1 on a molar basis and were termed . In the eleven normal converters (seven males and four females), the calculated conversion factors of 0:1 to 128 (sd 28:1 to 221 (sd 5·3):1 on a weight basis. The 52 d post-intestinal absorption conversion was estimated to be about 30 % of the total converted retinol.