Comparative Absorption and Transport of Five Common Carotenoids in Preruminant Calves

Abstract

Preruminant calves, maintained in a monogastric state by feeding an all-liquid diet, were used to compare the serum appearance and lipoprotein transport of five different carotenoids over 144 h. Thirty newborn calves were fed milk replacer for 1 wk and then randomly assigned to six groups (n = 5), with each group receiving a single 20-mg oral dose of β-carotene in water-soluble beadlets, canthaxanthin in water-soluble beadlets, lutein in oil, lycopene in oil, crystalline α-carotene in oil or crystalline β-carotene in oil as part of a morning meal. Serial blood samples were taken by jugular puncture for up to 1 wk post-dosing. Lipoprotein separation and analysis were completed with selected animals. All carotenoids were absorbed, but in variable amounts. At peak serum carotenoids levels, HDL contained 70–90% of the carotenoids. Canthaxanthin and lutein peaked earlier in serum (8 and 12 h) than did the less polar lycopene, α-carotene, and β-carotene (16, 24 and 24 h). Canthaxanthin and lutein were also cleared more quickly from the serum. Serum concentrations of α-carotene and lycopene displayed slower disappearance rates than did β-carotene. The peak serum level (nmol/L ± SEM) of canthaxanthin (392 ± 136) was lower than that of β-carotene (1245 ± 425), and carotenoids levels of calves receiving these commercial beadlet sources were higher than the serum levels of calves receiving β-carotene (45 ± 17.5), α-carotene (42 ± 18.0), lutein (51 ± 9.5) and lycopene (18 ± 4.6), which were fed in oil. The results show differential uptake and clearance of various carotenoids and enhanced uptake of beadlet forms of two carotenoids. We suggest that the preruminant calf is an excellent model in which to evaluate uptake and transport of carotenoids, especially for those carotenoids that are not approved for human feeding studies.