Retinal+(Vitamin+A)

Vitamin A is used for low light and color vision and gene transcription mostly. A deficiency of vitamin A will lead to night blindness and even birth defects.

Retinal, also called retinaldehyde or vitamin A aldehyde, is one of the many forms of vitamin A (the number of which varies from species to species). Retinal is a polyene chromophore, and bound to proteins called opsins, is the chemical basis of animal vision. Bound to proteins called type 1 rhodopsins, retinal allows certain microorganisms to convert light into metabolic energy.

Vertebrate animals ingest retinal directly from meat, or produce retinal from one of four carotenoids (beta-carotene, alpha-carotene, gamma-carotene, and beta-cryptoxanthin), which they must obtain from plants or other photosynthetic organisms (no other carotenoids can be converted by animals to retinal, and some carnivores cannot convert any carotenoids at all). The other main forms of vitamin A, retinol, and a partially active form retinoic acid, may both be produced from retinal.

Invertebrates such as insects and squid use hydroxylated forms of retinal in their visual systems, which derive from conversion from other xanthophylls. etinal disorders affect this vital tissue.

Retinal diseases can affect the area of the retina that serves your central vision (the macula and the fovea at the center of the macula). Many retinal diseases share common symptoms and treatments, but each has unique characteristics. The goal of retinal disease treatments is to stop or slow disease progression and preserve, improve or restore vision. Retinal problems can affect your vision, and some can be serious enough to cause blindness. Examples are
 * Retinal detachment - a medical emergency, when the retina is pulled away from the back of the eye
 * Macular pucker - scar tissue on the macula
 * Macular hole - a small break in the macula that usually happens to people over 60
 * Floaters - cobwebs or specks in your field of vision

Metabolic Functions

 * Vision
 * Gene Transcription
 * Immune Function
 * Reproduction
 * Bone Metabolism
 * Skin and Cellular Health
 * Antioxidant Activity