Red Algae

Red algae has two types of super nutrients: the antioxidant astaxanthin and sulphated polysaccharides that boost immunity.
There are a variety of red algae that emphasize each of these differently and they can be bought as isolated extracts or whole algae products.
Astaxanthin from the red algae species Haematococcus pluvialis has been considered the
most powerful and versatile antioxidant:
It can enter through cell membranes to the mitochondria.
It can utilize various sizes of free radicals including single oxygen.
These broad mechanisms of action give it unlimited applications for improving: skin, joint pain, eyes, endurance, heart, diabetes, etc.
Other carotenoids such as Lutein, Zeaxanthin are found in yellow and red fruits and vegetables, including green zucchini.
More is not necessarily better with carotenoids as Lester Packard explains in his book, The Antioxidant Miracle, as too much can give mixed results.
Negative results could also be from taking isolated supplements with cofactors and balance, along with the possibility of taking too much.
Astaxanthin is also found in pink seafood like salmon and shrimp, having found its way up the food chain. For that reason it's not always necessary to take a supplement if you eat wild salmon, not farmed salmon with the artificial color.
Other species of red algae have some astaxanthin and other carotenoids along with more immune boosters that may be more valuable depending on what your goal is.
Sulphated Polysaccharides
These have become famous for viral treatment of herpes lesions but would apply more broadly as an immune booster toward any infection or foreign body to be removed like toxicity and cancer. The mechanism of red algae have been studied:
Immune Cell Regulation: SPs can interact with and regulate the activity of various immune cells such as macrophages, lymphocytes (T and B cells), and natural killer (NK) cells.
This include strengthening:
Signaling Pathways
Complement System Activation
Antiviral and Anti-inflammatory Effects