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Vitamins: Essential Dietary Components required in our diet.
What are the two classes and there vitamins?
Water-soluble: Vitamins B, C
Fat-Soluble: Vitamins A, D, E, K.
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Absorption of vitamins differs. What are the % of fat soluble compare to water soluble?
Fat-soluble less efficiently absorbed (40-90%)
Water soluble (90+)
*Need fat to absorb fat-soluble vitamins
*Fat soluble vitamins can be stored but more toxicity
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Fat-sol. are transported via what in the lymph to the bloodstream?
Through *chylomicrons.
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Where are water-soluble vitamins absorbed into?
Absorbed into the portal vein.
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Where are fat-soluble vitamins stored?
Limited storage of water-sol vitamins except what two vitamins?
Fat-sol. stored in adipose and liver.
Except B-6 and B12
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Vitamin toxicity is most likely to occur within what two vitamins in high doses?
Vitamins A & D.
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Vitamin A. What are the dietary sources of RETINOIDS and CAROTENOIDS?
What is the most common carotenoid?
Ret: fish products)
Car: Veggies & fruits
*most common is Beta-carotene.
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Which is more absorbed, retinoids or carotenoids?
Carotenoids.
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What are the functions of Vit A (Retinoids)?
(4)
Cell signaling
Vision
Immune Function
Dermatology
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Vitamin A diseases. Do most Americans meet DRI for Vit A?
What is it the leading cause of in the world?
What can it be caused by?
Yes, most americans meet DRI.
Blindness ( 1/2 million children/year in poor countries.
Caused by liver disease or fat malabsorption
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Vitamin A disease toxicities is termed what?
What is the term called causing birth defects?
Termed as "Hypervitaminosis A"
UL is 3000 mg/day of retinoids
Teratogenic (
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Is carotenoid, toxic?
No. Absorption & conversion to retinoids slows w/ increased retinoid intake.
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Vitamin D. Are they required in diets?
What are some sources of Vit D?
Where does it travel to (2) where it is further metabolized to form active forms?
No, they're conditional (can get elsewhere).
Milk, fish, dairy, fortified breakfast cereals.
Transported to liver & kidney.
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Absorption & metabolism of Vit D. Where is it absorbed and packaged?
Limited storage where?
How's it excreted?
Metabolism is regulated by what?
*Chylomicrons.
*Limited storage in liver & adipose.
Excreted through urine .
Metabolism regulated by Parathyroid hormone.
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What are the functions of Vit D?
Calcium & Phosphorus homeostasis
Bone health
Immune function
***We don't know A LOT about Vit D.
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What two body parts are important in the formation of active form of Vit D?
Kidney & bone.
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Diseases of Vit D. What is the term for deficiencies in children, in adults?
Deficiencies occur from what?
Children: Rickets
Adults: Osteomalascia (soft bones)
Deficiencies occur w/ supplements.
Can be fatal
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