Bioavailability of α-+β-carotene in Type 1 diabetic patients

Abstract

Type 1 diabetics are considered to be at risk for marginal status of vitamin A, although they frequently present higher serum levels of provitamin A carotenoids, suggesting an impaired bioconversion into retinol. Our aim was to assess the bioavailability of provitamin A carotenoids (absorption and conversion into retinol) in these subjects compared to non-diabetics using the post-prandial triacylglycerol-rich lipoprotein fractions (TRL) model and the depletion rate in serum after 21 days on a low-carotenoid diet. The analysis was performed by a quality-controlled HPLC method. In both groups, total retinyl esters accounted for approximately 60% of the total amount absorbed from the capsule, retinyl palmitate being the predominant ester and efficacy of conversion (AUC total esters/AUC α-+β-carotene) was similar. Markers of glycemic control were correlated with absorption but not with conversion into retinol. Serum depletion rate in diabetics was not significantly different from control subjects. Provitamin A carotenoids bioavailability in type 1 diabetics is, at least qualitatively, similar to control subjects.