Vits II Flashcards
What are the normal biological processes that generate ROS?
ETC
H2O2 production
What is the enzyme that converts Hydroxyl radicals to H2O2?
Superoxide dismutate
What is the enzyme that catalyses the reaction of hydrogen peroxide to water?
Catalase
What is the enzyme that converts glutathione and hydrogen peroxide to water?
Glutathione peroxidase
Is bilirubin an antioxidant?
Yes
alpha (or gamma) tocopherol is also known as what?
Vitamin E
beta and alpha carotene are lipid or water soluble?
Lipid
Lycopene is a lipid or water soluble antioxidant
Lipid
Lutein is a lipid or water soluble antioxidant?
Lipid
What are the three metals that are involved in superoxide dismutase reaction?
Cu
Zn
Mn
What is the metal involved in glutathione peroxidase?
Se
Urate is a lipid or water soluble antioxidant?
Water
Which can be supplemented in the diet: glutathione or lipoate?
Lipoate
What are the two vitamins in the glutathione/lipoate redox cycles? Which amino acid?
E and C
Cysteine
Why are the brain and lung particularly susceptible to ROS?
High oxygen exposure
True or false: vitamin E alone has been shown to reduce the incidence of CVD
False
True or false: some studies show that vit E and C supplementation can reduce the amount of plaques in vessels
True
True or false: the more colorful the vegetable, the more antioxidants it is likely to have
True
True or false: whole foods have not been shown to have increased antioxidant activity
False-there are studies, but MOA unknown
Higher serum levels of what antioxidants have been shown to lower the risk of developing macular degeneration
Lutein
Zeaxanthin
Higher serum levels of which 5 vitamins (and one metal) have been shown to lower the risk of developing macular degeneration?
E C B6 B12 Folate Zn
True or false: treatment of AMD with vit C, E, beta carotene, Zn and Cu has been shown to slow the progression of AMD
True
What are the factors that are needed to ensure sufficient fat soluble vitamin uptake?
Bile salts and carrier proteins
Which fat soluble vitamin does not have a TUL?
K
Vitamin A is involved in what important reaction in the eye?
Beta-carotene to retinol
Which vitamin metabolites are involved in growth and differentiation of epithelial, nervous, bone, and immune function?
A
Deficiency in vitamin A results in what?
Poor dark light adaptation
Xerosis
Xeroderma
What are the two general sources of vitamin A?
Dark green vegetables
Orange fruits and vegetables
What is the function of vitamin D?
Regulator of bone metabolism and Ca
Deficiency in vitamin D results in what (adults and children)?
Rickets in children
Osteomalacia in adult
What are the sources of vitamin D?
Fish
Fortified dairy
Eggs
What is the role of vitamin E?
Antioxidant
Gene expression
Deficiency in vitamin E results in what (infants, and children/adults?
Infants=anemia
Children/adults= neuropathy
What are the sources of vitamin E? (3)
Vegetable oils
Nuts
Green vegetables
What is the role of vitamin E? (3)
Blood coagulation (10, 7, 9, 2)
Antioxidant
Bone growth
Deficiency in vitamin E results in what?
Hemorrhagic disease of newborns
Defective blood clotting
What are the sources of vitamin K?
Gut flora
Dark vegetables
What are vitamers?
structural isomers of vitamins
How many vitamers of vit E are there? What does this depend on?
8
Where methyl group is placed
Vitamin E acts as an antioxidant in cell membranes, particularly in which three tissues?
Brain
Lungs
RBCs
High doses of which fat soluble vitamin can interfere with the other fat soluble vitamins’ functions?
E
How do high doses of vitamin E affect vitamin A?
Lower rate of A depletion
True or false: vitamin E deficiency is rare
True
What is abetalipoproteinemia?
Genetic disease where fat Vit deficiency d/t a lack of apoprotein B
What are the symptoms of high vitamin E?
Bleeding/petechiae
Why can vitamin D be considered a hormone?
Can be synthesized from the body, but needs to be supplemented
What is the role of vitamin D in immunity?
Macrophages make Vit D3, which activates immune cells
UVB converts which molecule to vitamin D3?
7 dehydrocholesterol
Cholecalciferol is what?
Vit D3
What is ergocalciferol?
Vit D2
Vitamin D2/3 in the liver is converted to what chemical? Where does this go?
Calcidiol
Goes to the kidneys
Blood tests checking for vitamin D is looking for which molecule?
Calcidiol
What is the active form of vitamin D?
Calcitriol (1,25 dihydroxy vit D)
What is the inactive form of vitamin D? Why is this important?
Calcitroic
Pathway for excess vit D to be eliminated
Above which latitude line is vit D supplementation necessary?
37 degrees
What is the main hormone in the body that pulls Ca from bone?
PTH
What are the homeostatic effects of PTH on Ca (3)?
- Pulls Ca from the bone 2. Increases Vit D formation in the kidneys
- Increases Ca absorption from gut
What is the relationship between levels of Vit D and PTH secretion?
Inversely related
What are the units used to measure Vit D concentrations (american + rest of world conversion)?
1 ng/ml (=2.5 nmol/L)
What is the RUD for Vit D?
800 IU/d
What is the range of normal values for Vit D?
22.5 - 130
What is the optimal SERUM level of Vit D?
80 nmol/L
Vit D is suspected to play a role in preventing which bacterial disease?
TB
What is characteristic of vitamin D serum levels in patients with autoimmune diseases?
Low or have receptor polymorphisms
Which is a more bioactive form of vit D?
D3
What is the role of retinal?
Captures light in cones of eyes
What are the two major forms of carotenoids?
Provitamin A
Beta/other carotene
Which vitamin is used in the treatment of psoriasis/acne?
Vit A
True or false: vit A deficiency is rare in the US
True
What is xerophthalmia, and which vitamin deficiency causes this?
Dry eyes
A
What are Bitot spots? Which vit deficiency causes this?
Build up of keratin on the conjunctiva d/t vit A deficiency
What are the toxic effects of vit A?
Anorexia
Congenital malformations
Various CT effects
What is hypercarotenosis? How concerning is this?
Build up of beta carotene, causing orange skin
Bening
What is phylloquinone?
Plant vit K
What is menaquinone?
Animal/bacterial vit K
What is menadione?
synthetic form of vit K
What is the role of vit K in cell function?
Helps in post translational modification of proteins
What is the protein in bone that is affected by Vit K?
Gla protein
Which fat soluble vitamin is produced by gut flora, and thus requiring infants to receive supplementation?
K
True or false: both the natural and synthetic forms of vit K can reach toxic levels?
False–just the synthetic form
What are the two enzymes that Warfarin inhibits?
Vitamin K epoxide reductase
Quinone reductase
Vitamin C reacts with which radical to produce water?
OH radical
Which vitamin reacts against PUFAs?
Vit E
Glutathione and lipoate are kept reduced by which electron carrier molecule?
NADH/NADPH
Ceroid pigment accumulation is a microscopic finding due to what?
oxidation of fats
Lack of which vitamin can cause Neurological issues such as loss of vibratory sense and incoordination of limbs ?
Vit E
What is the effect of PTH on the kidney?
Increases Vit D synthesis, for increased absorption from the gut
