β‐carotene (BC) bioconversion is similar in men and women

Abstract

Gender differences in plasma retinol and provitamin A carotenoids have been previously reported, with retinol being higher in men and BC higher in women(1). Furthermore, lower conversion efficiency is correlated with BMI in women but not in men(2). We investigated BC conversion efficiency in 23 female and 19 male volunteers by co-administering 2 mg [13C10] BC and 1 mg [13C10]-retinyl acetate. Data on fraction of the administered doses in plasma vs. time for each subject were analyzed by model-based compartmental analysis using the Simulation, Analysis and Modeling software WinSAAM. Relative absorption of BC in the first 24 hours represented 11% of total ingested [13C10]BC, with an inter-individual coefficient of variation of 49%. Although significantly higher plasma concentrations of preformed [13C10]-retinol and bio-converted [13C5]-retinol were found in men compared to women, differences in retinoid concentrations were independent of [13C10]BC cleavage, in that model-calculated bioconversion was not significantly different between men and women (Figure 1). Fig 1: Effect of gender on provitamin A conversion efficiency. In summary, application of [13C10]-retinyl acetate with [13C10]BC confirms that there are no differences in BC conversion efficiency between men and women.