Absorption characteristics and in vivo behavior of astaxanthin isomers: insights from the administration of highly purified (all- E )-, (9 Z )-, and (13 Z )-astaxanthin in male mice

(13 Z )-Astaxanthin exhibits significantly higher bioavailability, systemic retention, and hepatic accumulation than the (all- E )- and (9 Z )-isomers, highlighting its potential for nutraceutical applications.