Vitamin B6 (pyridoxine) is required for the synthesis of the neurotransmitters serotonin and norepinephrine and for myelin formation. Pyridoxine deficiency in adults principally affects the peripheral nerves, skin, mucous membranes, and the blood cell system. In children, the central nervous system (CNS) is also affected. Deficiency can occur in people with uremia, alcoholism, cirrhosis, hyperthyroidism, malabsorption syndromes, congestive heart failure (CHF), and in those taking certain medications. Mild deficiency of vitamin B6 is common. Major sources of vitamin B6 include: cereal grains, legumes, vegetables (carrots, spinach, peas), potatoes, milk, cheese, eggs, fish, liver, meat, and flour. Pyridoxine is frequently used in combination with other B vitamins in vitamin B complex formulations.
Astaxanthin is classified as a xanthophyll, which is a carotenoid pigment, and can be found in microalgae, yeast, salmon, trout, krill, shrimp, crayfish, crustaceans, and the feathers of some birds. Haematococcus pluvialis , a green microalga and one of the richest sources of natural astaxanthin, was reviewed and cleared for marketing by the United States Food and Drug Administration (FDA) in August 1999 as a new dietary ingredient by means of the Dietary Supplement Health and Education Act (DSHEA) (21 CRF part 190.6). Astaxanthin is most commonly used as an antioxidant and may be beneficial in decreasing the risks of certain chronic diseases, such as cancer and cardiovascular diseases. Astaxanthin may also be effective in carpal tunnel syndrome, rheumatoid arthritis, muscle strength and endurance, high cholesterol (LDL oxidation), musculoskeletal injuries, and male infertility. Astaxanthin has been used as a feed supplement and food coloring additive for salmon, crabs, shrimp, chickens, and egg production. According to the Code of Federal Regulations, astaxanthin is generally recognized as safe (GRAS) when used as a color additive in salmon foods to obtain the desired pink to orange-red color.