Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8288502 | Archives of Biochemistry and Biophysics | 2018 | 22 Pages |
Abstract
The vitamin A value (bioefficacy) of provitamin A carotenoids is determined by absorption of the carotenoid (bioavailability) and its subsequent conversion to retinol (bioconversion). Here we show that intestinal bioconversion of β-carotene can be estimated based on analysis of a single plasma sample collected 6â¯h after subjects ingest a test dose of stable isotope-labeled β-carotene from the ratio of retinyl esters to retinyl esters plus β-carotene. Plasma isotope ratio predictions of bioconversion ranged from 50 to- 93% (mean 76%) for 45 healthy young adults with low vitamin A stores. Results were the same as predictions made by a traditional area-under-the-curve method calculated from 0 to- 8â¯h or a modified area-under-the-curve method calculated from 0 to- 12â¯h. The modified method may provide better estimates of bioconversion between 8 and 24â¯h after ingestion of a carotenoid dose when stable isotopes cannot be used due to cost or logistics. Furthermore, because the plasma isotope ratio method requires only one blood sample and no isolation of triglyceride-rich lipoproteins, its use will facilitate estimation of provitamin A carotenoid bioconversion in human subjects and especially children, in whom repeated blood sampling is not feasible.
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Authors
Jennifer Lynn Ford, Michael H. Green, Joanne Balmer Green, Anthony Oxley, Georg Lietz,