Kinetics of plasma and erythrocyte-astaxanthin in healthy subjects following a single and maintenance oral dose

Aim and Background: Astaxanthin is a unique carotenoid of predominantly marine origin providing the pink-red color to certain microalgae and accumul ating in various animals higher in the food chain. It is an antioxidant without pro-oxidant properties or known side-effects following oral intake. Materials and Methods: We investigated astaxanthin kinetics in plasma and erythrocytes (red blood cells [RBC]) of four healthy adults after a single oral 40 mg dose. Plasma- and RBC-astaxanthin were measured during 72 h. Subsequently, an 8 mg/day dose was given during 17 days. Plasma- and RBC-astaxanthin were measured each morning. Results: Plasma-astaxanthin reached a peak (from 79 to 315 nmol/L) after 8 h and then declined (half-life, 18 h). Within 72 h, plasma-astaxanthin had returned to baseline. RBC-astaxanthin reached a peak (from 63 to 137 nmol/L packed cells) at 12 h and subsequently disappeared (half-life, 28 h). During the daily dose, plasma-astaxanthin 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.