Plasma kinetics of lutein, zeaxanthin, and 3-dehydro-lutein after multiple oral doses of a lutein supplement.
BACKGROUND
Adequate intake of lutein is postulated to reduce the risk of age-related macular degeneration, but kinetic information for developing a dosing regimen is sparse.


OBJECTIVE
The objective was to characterize lutein plasma kinetics in a multiple dosing design and to assess the effects of lutein intake on concentrations of other plasma carotenoids.


METHODS
After a run-in period of 7 d, 19 healthy volunteers were assigned to receive daily oral doses of 4.1 mg lutein (n = 8; group 1) or 20.5 mg lutein (n = 8; group 2) for 42 d or no lutein (n = 3; control group). The supplement contained 8.3% zeaxanthin relative to lutein (100%). The time profiles of plasma xanthophyll concentrations were monitored over the dosing phase, and samples were collected frequently on day 42 and for 24 d after dosing.


RESULTS
Average plasma all-E-lutein concentrations increased from 0.14 to 0.52 +/- 0.13 and 1.45 +/- 0.69 micromol/L in groups 1 and 2, respectively. Dose-normalized lutein bioavailability in group 2 was approximately 60% of that in group 1. Kinetic disposition half-life did not differ significantly between groups. On average, dosing for 18 d was required to reach a >90% fraction of the steady state concentration, which is consistent with an effective half-life for accumulation of approximately 5.6 d. Plasma kinetics of all-E-lutein were paralleled by those of all-E-3-dehydro-lutein. Kinetic analysis indicated formation of all-E-3-dehydro-lutein from lutein. Lutein was well tolerated and did not affect the concentrations of other carotenoids.


CONCLUSIONS
Long-term supplementation with 4.1 and 20.5 mg lutein as beadlets increased plasma lutein concentrations approximately 3.5- and 10-fold, respectively.
Institute of Clinical Pharmacology, HELIOS Klinikum Wuppertal, University of Witten/Herdecke, Wuppertal, Germany.
Petra A
PA
Thürmann
Wolfgang
W
Schalch
Jean-Claude
JC
Aebischer
Ute
U
Tenter
William
W
Cohn
D000284:Administration, Oral; D000328:Adult; D019540:Area Under Curve; D002338:Carotenoids / Q000097:blood; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D006207:Half-Life; D006801:Humans; D014975:Lutein / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D013237:Stereoisomerism; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*
D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D014975:Lutein