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41 Cards in this Set
- Front
- Back
Vitamin A
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retinol, retinal & retinoic acid
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B-carotene
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2 retinal molecules linked
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retinal to retinol
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retinaldehyde reductase
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Vitamin A functions
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embryogenesis, photoreception, mucous production and normal growth regulation
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Vitamin A sources
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as retinol in liver, whole milk & whole eggs (preformed vit A)
as carotenoids in carrots, canteloupes, sweet potatoes & spinach (b-carotene, a-carotene & b-cryptoxanthin) |
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caretenoids without vit A activity
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lycopene, lutein & zeaxanthin (90 %)
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Vit A defficiency
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night blindness, anemia, hyperkeratinosis, xerophthalmia
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Excess Vit A
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bone pain, hepatosplenomegaly, hyperkeratosis (dry, bumpy skin), naueau & diarrhea
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Stored Vitamins
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liver: vit A, B12 (6 years),
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Vit D
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1,25-dihydroxy vitamin D3 or calcitriol
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25-OH D3 to 1,25-dihydroxy vitamin D3
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D3-25-hydroxylase in the in the proximal convoluted tubules of the kidneys, bone, intestine & cartilage
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Vit D function
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calcium and phosphorus regulation
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Sources of Vit D
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fish oils, butter, cream egg yolk, liver
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Vit D defficiency
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rickets & osteomalacia
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excessive Vit D
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headache, nausea, bone fragility, retarded growth & calcifiaction of soft tissues
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Vitamin E most potent form
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a-tocopherols
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Vit E deficiency
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RBC fragility & neurologic disorders
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Vit E excess (>1000mg)
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decreased Vit A stores, impaired bone mineralization & prolonged blood coagulation
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Vit K
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K1 phylloquinone
K2 menaquinone K3 menadione |
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Thiamin to thiamin pyrophosphate
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thiamin diphosphotransferase
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Vit B1 function
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cofactor for pyruvate dehydrogenase and a-ketoglutarate dehydrogenase & transketolase of the pentose phosphate pathway
-->> energy |
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Vit B1 defficiency
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beriberi & wernicke-korsakoff syndrome
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Vit B2
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precursor for coenzymes
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sources of Vit B2
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green, leafy vegetables; meats and dairy
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niacin function
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required for the synthesis of the active forms of vitamin B3 which functions include lactate dehydorogenase and malate dehydorogenase
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Niacnin synthesis
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60 mg tryptophan and vit B1, B2 and B6
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sources of niacin
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lean meat, fish, poultry & peanuts
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niacin defficiency
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glossitis, dermatitis, weight loss, diarrhea, depression and dementia & pellagra
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pantothenic acid
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required for synthesis of coenzyme A and ACP used in the TCA cycle
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Vit B6
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pyridoxal, pyridoxamine & pyridoxine
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active Vit B6
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pyridoxal phosphate (PLP) with zinc
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Vit B6 fucntion
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AA synthesis/catabolism, glycogenolysis & GABA synthesis
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Vit B6 excess
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seizure risk
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Folic acid
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converted to tetrahydofolate by dihydrofolate reductase
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folic acid functions
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one carbon transfers: methyl, methylene, methenyl,formyl or formimino groups.
serine, methionine, glycine,choline, purines & dTMP With B12 THF converts homocysteine to methionine |
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folic acid deficiency
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macrocytic anemia
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folate absorption impaired
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anticonvulsants and oral contraceptives
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Vit B12 function
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cofactor for methylmalonyl-CoA mutase and methionin synthase (regenerates THF)
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Vit B12 deficiency
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pernicious anemia, folate trapping, neurologic demyelinatino, elevated homocysteine & defective collagen
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Vit C function
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ascorbic acid acts as reducing agent, collagen in bone, catablolism of tyrosine, epinephrine synthesis, synthesis of bile acids & interferon, mucous membrane integrity, and inflammatory reactions
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Vit C deficiency
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scurvy (bruised skin, muscle fatigue, swollen gums, poor wound healing, osteoporosis, anemia, and hemorrhaging.
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