Astaxanthin can be obtained naturally as well. Wild salmon. Emphasis on wild, not farmed. One of the reasons wild salmon have a bright red pigment is because of the astaxanthin.

While we're on subject, wild salmon has one of the highest VitaminD counts of all food. One 3oz serving = 500IU. Probably in the top-three healthiest foods on Planet Earth (if you can even make such a criteria)