Aim & background: Astaxanthin is a unique carotenoid of predominantly marine origin providing the pink-red color to certain microalgae and accumulating in various animals higher in the food chain. It is an antioxidant without pro-oxidant properties or known side-effects following oral intake. Methods: We investigated astaxanthin kinetics in plasma and erythrocytes (RBC) of four healthy adults after a single oral 40 mg dose. Plasma- and RBC-astaxanthin were measured during 72h. Subsequently, an 8 mg/day dose was given during 17 days. Plasma- and RBC-astaxanthin were measured each morning. Results: Plasmaastaxanthin reached a peak (from 79 to 315 nmol/L) after 8h and then declined (half-life, 18h). Within 72h, plasma-astaxanthin had returned to baseline. RBC-astaxanthin reached a peak (from 63 to 137 nmol/L packed cells) at 12h and subsequently disappeared (half-life, 28h). During the daily dose, plasmaastaxanthin increased until day 10 (187 nmol/L) and then decreased to a steady concentration similar to that reached after 2 days. RBC-astaxanthin appeared to be highly variable (group median concentration, 86 nmol/L packed cells). Conclusion: We found high intra- and inter-individual variations, especially in RBC, possibly due to non-standardized time difference between astaxanthin intake and sampling, fl uctuating background intake from the diet, variable bioavailability, large distribution volume, degradation or others. Oral astaxanthin is rapidly absorbed and incorporated into RBC. The subsequent rapid decline suggests that, for a higher-than-baseline status, astaxanthin should be taken daily, at least in an early phase when total body equilibrium, if any, has not been reached yet.
Key words : Antioxidant ; carotenoid ; humans ; half-life ; status ; absorption .