Food Grade 99% Vitamin A Palmitate Powder Retinoic Acid Powder

1 The classic or earliest recognized function of vitamin A is to participate in the maintenance of scotopic photoreceptor circulation in visual cells.The rhodopsin contained in the rod cells on the retina is composed of 11-cis-retinal combined with opsin, which is sensitive to dark light.After rhododendron photosensitive, 11-cis-retinal is converted to all-trans-retinal and separated from opsin to generate visual electrical signal.The dissociated all-trans retinal is reduced to all-trans retinol in the rod cells, and is transported to the retinal pigment epithelium, where together with the all-trans retinol from plasma, a complex isomerization beginsIt participates in the supply of 11-cis-retinal needed for the resynthesis of rhodopsin, and maintains dark-light adaptation.Therefore, to maintain good dark-light vision, it is necessary to continuously supply sufficient 11-cis-retinal to rod cells.When vitamin A is deficient, the supply of 11-cis-retinal decreases and the dark adaptation time prolongs.

2 Vitamin A is a coenzyme that regulates glycoprotein synthesis, stabilizes the cell membrane of epithelial cells, and maintains the morphological integrity and function of epithelial cells.This effect of vitamin A on tissue function and integrity is achieved by mediating the exchange of information between adjacent cells.Vitamin A deficiency causes desiccation of the epithelium, transformation of normal columnar epithelial cells into horn-shaped overlying squamous cells, resulting in cytokeratinization.The epithelial cells of various tissues in the whole body will be affected, but the first ones to be affected are the epithelial cells of the conjunctiva, cornea and lacrimal gland. The reduction of lacrimal gland secretion leads to dry eye, dryness, softening and even perforation of the conjunctiva or cornea.Epithelial cells such as skin hair follicles, sebaceous glands, sweat glands, tongue taste buds, respiratory and intestinal salivary membranes, urinary and reproductive salivary membranes will all be affected, resulting in corresponding clinical manifestations and impaired mucosal barrier function.