Fat soluble vitamin - Fat Soluble Vitamin Vitamin A-Active...

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Fat Soluble Vitamin Vitamin A-Active forms of Vitamin A retinol involved in transport and storage absorbed in the intestines retinal is converted into retinal Retinal for vision health retinal can be converted back into retinol retinal --> retinoic acid can't go the other way light hits rods and cones rods and cones have visual pigments rod help sees in the dark cones are responsible for color rhodopsin-consist of a protein called opsin and attached to the opsin is cis retinal rhodopsin hits retina-->cis-retinal turns into trans retinal which is different from cis retinal a nerve impulse is than transmitted to the brain and that impacts what you see after the impulse, trans-rhoposin turns back into cis=rhoposin recycled retinal BUT some of the retinal is destroyed so a new supply of retinal must be provided constanstly Retinoic Acid involved in cell development cell differentation-statges that cells go through from immuture cells to mature cells specifically the linning like skin and stomach and lungs invovled in immunity
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involved in developing babies direct the expressioin of genes in the embyro bone growth -helps to elongate the bone by stimulating a cell type that is invovled in cells taking off bones called an osteoblast so that more bones can be desposited so that the bones can elongate Lack of Vitamin A affects bone growth Precursor to Vitamin A beta cryptoxanthin, beta carotene and alpha carotene (not active form of vitamin A) not all of them can be converted into vitamin A ALL OF THEM are antioxideants INDEPENDENT of their function of vitamin A eta carotene and alpha carotene beta cryptoxanthin lycopene lutein and zeazanthin (accumulate in the back of the retina to protect the macula from free radical)-- >decreases with age Vitamin A Sources (active form) most form of active VA is found as retinol milk and milk products liver (bc vitamin A is stored in the liver) fatty fish salmon tuna butter eggs Carotenoids (not the active form, our bodies need to convert it into vitamin A) dark green vegetables
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red/orange vegetables red/orange fruits conversion of carotenoids is not very efficient higher levels of vitamin A may decrease bone density over time, bad for women Vitamin A deficiancy-slowly happens because we store vitamin A in the tissues early symptoms night blindness-->can't recover from quick flashes of light very greatly increase infections because epithelial cells are not functioning correctly and epith infections are responsible for making mucus to protect you from bacterial infection later symptoms xeropthalmia early stage of seropthalimia xerosis-where your corina start to degrade, becomes hard and dry bitot spots-deposited caronoids blindness-keratomalacia late-->hyperkeratosis which means that a lot of karatin is deposisted around your nails and hair death vitamin A toxicity 5X RDA over time supplements is the only way you can get toxicity of Vitamin A bone loss acne medication-->Accutane causes birth defect birth defects
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Fat soluble vitamin - Fat Soluble Vitamin Vitamin A-Active...

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