Studies on the application of the relative-dose-response test for assessing vitamin A status in older adults

Bulux, Jesús; Carranza, Elizabeth; Castañeda, Carmen; Solomons, Noel W.; Sokoll, Lori J.; Morrow, Frank D.; Russell, Robert M.

doi:10.1093/ajcn/56.3.543

Cited by 12 publications

(2 citation statements)

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“…Whatever the mechanism involved, it is tempting to suggest that this "abnormal" postprandial plasma retinol response is related to the higher fasting plasma retinol concentrations that have been observed in elderly as compared to young subjects in several studies (8)(9)(10). Furthermore, this phenomenon might partly explain why the RDR test is not as reliable in elderly as in young people to detect vitamin A deficiency (27).…”

Section: Discussionmentioning

confidence: 99%

“…As aging affects numerous physiologic processes, it may directly or indirectly affect vitamin A postprandial plasma transport at different levels: (a) it is possible that the age-related alterations of gastrointestinal tract functions (19)(20)(21)(22) might modify the efficiency of vitamin A intestinal absorption in older subjects; (b) the age-related modification of enterocyte functions might affect the esterification processes of retinol by impairment of either lecithin-retinol acyltransferase (LRAT) or acyl CoA-retinol acyltransferase (ARAT) (23)(24)(25); (c) the plasma transport of retinyl esters from the intestine to the liver is likely affected, as it has been shown that aging delays the clearance of plasma retinyl palmitate (15), but it is not known whether this phenomenon is specific for retinyl palmitate or exists for the other retinyl esters found in the chylomicrons; (d) finally, it is not known if agerelated modification of liver cells (26) or extrahepatic cells functions can affect plasma retinol homeostasis in elderly people, but the low efficiency of the relative dose response (RDR) test in elderly peoples (18,27) to detect vitamin A deficiency suggests that this can be the case.…”

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confidence: 99%

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Comparison of the Postprandial Plasma Vitamin A Response in Young and Older Adults

Borel¹,

Mekki

Boirie‌

et al. 1998

The Journals of Gerontology Series A: Biological Sciences and M

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To assess the influence of age on vitamin A intestinal and liver metabolism in humans, the postprandial plasma concentrations of intestinal-originated vitamin A, i.e., retinyl esters, and liver-originated vitamin A, i.e., retinol, were compared in eight young (20-30 years old) and eight elderly (64-72 years old) healthy men. Plasma and chylomicron retinyl esters and retinol concentrations were measured for up to 24 h following the intake of a test meal that contained 23,300 RE retinyl palmitate. The chylomicron retinyl palmitate response (area under the curve) was not significantly different between the two groups, but its peak was slightly delayed (1 h) in the elderly men. The proportion of the different retinyl esters secreted in the chylomicrons was not significantly different between the two groups. The postprandial plasma retinol concentration did not change in the young participants, whereas it significantly increased in the elderly. These results suggest that vitamin A intestinal absorption and retinol intestinal esterification processes are not markedly modified in the elderly, whereas the chylomicron clearance and the regulation of postprandial plasma retinol concentration are apparently altered in these subjects.

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Section: Discussionmentioning

confidence: 99%