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Hypervitaminosis A refers to the toxic effects of ingesting too much preformed vitamin A (retinyl esters, retinol, and retinal). Symptoms arise as a result of altered bone metabolism and altered metabolism of other fat-soluble vitamins. Hypervitaminosis A is believed to have occurred in early humans, and the problem has persisted throughout ...
The physiologic basis lies in pregnancy whereby the mutated gene product, retinol binding protein (RBP), has negative effects in transferring vitamin A from maternal liver storage sites to the placenta, and then again on the fetal circulation side when delivering vitamin A from the placenta to developing fetal tissues, most notably the ...
Retinol, also called vitamin A 1, is a fat-soluble vitamin in the vitamin A family that is found in food and used as a dietary supplement. [3] Retinol or other forms of vitamin A are needed for vision, cellular development, maintenance of skin and mucous membranes, immune function and reproductive development. [3]
Regulation of transport and metabolism of retinol necessary for a successful pregnancy is accomplished via RBP. Retinol-binding proteins have been identified within the uterus, embryo, and extraembryonic tissue of the bovine, ovine, and porcine, clearly indicating that RBP plays a role in proper retinol exposure to the embryo and successful ...
Retinyl acetate (retinol acetate, vitamin A acetate) is a natural [dubious – discuss] form of vitamin A which is the acetate ester of retinol. It has potential antineoplastic and chemopreventive activities.
The causes are vitamin A deficiency during pregnancy, followed by low transfer of vitamin A during lactation and infant/child diets low in vitamin A or β-carotene. [ 22 ] [ 19 ] The prevalence of pre-school age children who are blind due to vitamin A deficiency is lower than expected from incidence of new cases only because childhood vitamin A ...
Alternation of side chains and end groups creates the various classes of retinoids. [citation needed] First generation retinoids are produced naturally in the body and interact with their normal biological counterparts, such as retinol binding protein 4 for retinol, retinoid receptors for all-trans-retinoic acid or 9-cis-retinoic acid.
Other severe side effects include high white blood cell counts and blood clots. [8] Use during pregnancy is contraindicated due to the risk of birth defects. [8] [1] It is in the retinoid family of medications. [9] Tretinoin was patented in 1957 and approved for medical use in 1962. [13] It is on the World Health Organization's List of ...