VitaminE family biochemical function

Two retinoids, retinoic acid and retinal, appear to have most of the biochemical functions attributed to vitamin A Retinoic acid is required for cell differentiation and is the ligand for two families of nuclear receptors, RAR . y and RXR 0 y. These receptors are part of a family of superreceptors that include the steroid hormones and cholecalciferol. Vitamin A deficiency can lead to a variety of symptoms depending on the age of the deficient person. The most serious syndrome is keratomalacia, which results in desiccation, ulceration, and xerophthalmia of the cornea and conjunctiva. It is one of the leading causes of blindness in infants and children. 

Duester, G. Families of retinoid dehydrogenases regulating vitamin A function production of visual pigment and retinoic acid. Eur. J. Biochem. 267 4315—4324, 2000. 

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