Abstract
We investigated the time course and the reproducibility of the relative- dose-response (RDR) test for assessing vitamin A status in older adults. The maximum plasma retinol response to 480 retinol equivalents (RE) of retinyl palmitate in abnormal responses was at 6 or 7 h after dosing compared with the 5-h sampling interval recommended by others for younger adults and children. With respect to reproducibility, the diagnostic concordance of two RDR tests at 7-d intervals in 14 elders was 71%. In 29% of tests, one test was abnormal and the other normal. Linear regression of the two RDR values in these 14 subjects gave a correlation coefficient of -0.08. We conclude that the procedure for the RDR should be modified when applied to persons > 60 y of age, and that multiple repetitions of the test are needed to provide a stable indication of vitamin A stores in an elderly individual.
Original language | English (US) |
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Pages (from-to) | 543-547 |
Number of pages | 5 |
Journal | American Journal of Clinical Nutrition |
Volume | 56 |
Issue number | 3 |
DOIs | |
State | Published - 1992 |
Externally published | Yes |
Keywords
- Aging
- relative dose response
- retinol
- vitamin A
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics