FNDH 620 UPDATED EXAMS STUDY GUIDE QUESTIONS
AND SOLUTIONS GUARANTEE A+
✔✔Vitamin D becomes part of __________ and then enters the __________
circulation. - ✔✔Vitamin D becomes part of *chylomicrons* and then enters the *lymph*
circulation.
✔✔40% of vitamin D is transported in chylomicrons. The remaining 60% is transported
by what protein? - ✔✔D-binding Protein (DBP)
- this is also the same protein that picks up vitamin D created in the skin
✔✔The efficiency of binding to vitamin D is increased after two ____________. -
✔✔The efficiency of binding to vitamin D is increased after two *hydroxylations*.
✔✔Both the _____ and the _____ add a hydroxyl group to the vitamin D structure. -
✔✔Both the *liver* and the *kidneys* add a hydroxyl group to the vitamin D structure.
✔✔When vitamin D levels are low, what becomes more efficient? - ✔✔25-hydroxylase
✔✔When light hits the skin, what is the pathway for it to become vitamin D? - ✔✔Sun
- skin
-- 7-dehydrocholesterol
--- liver: 1st hydroxylation
---- kidney: 2nd hydroxylation
----- 1, 25(OH)2VitD3
------ Metabolically active form
✔✔What is the most potent vitamin D metabolite? - ✔✔1,25-dihydroxycholecalciferol
✔✔Functions of vitamin D - ✔✔- regulation of gene expression
- affects calcium & phosphate homeostasis
- differentiation of stem cells in bone tissue
- differentiation of hair follicles & skin cells
✔✔AI recommendation for vitamin D in infants to 50yrs - ✔✔5 mcg/day
✔✔AI recommendation for vitamin D in > 50yrs - ✔✔15 mcg/day
✔✔AI recommendation for vitamin D in > 70yrs - ✔✔20 mcg/day
✔✔UL recommendation for vitamin D in > 9yr - ✔✔50-100 mcg
✔✔What diseases are caused by vitamin D deficiency? - ✔✔- Rickets
,- Osteomalacia
✔✔Failure of growing bones to mineralize properly. This results in bowing of long,
weight-bearing bones. - ✔✔Rickets
✔✔Vitamin D deficiency in adults. This results from decreased calcium and phosphate
absorption. aka, soft bones - ✔✔Osteomalacia
✔✔At risk groups for vitamin D deficiency - ✔✔- insufficient sunlight exposure
- aging reduces D synthesis in skin
- fat malabsorption
- anticonvulsant drug therapy
- breast fed infants
- renal disease
✔✔Tocopherols are __________ while tocotrienols are __________. - ✔✔Tocopherols
are *saturated* while tocotrienols are *unsaturated*.
✔✔Food sources of vitamin E - ✔✔- plant oils
- oil derived products
- wheat germ & oil & nuts
- some fruits & vegetables (peaches & asparagus)
- meat & fish
✔✔Tocopherols are ______ prevalent than tocotrienols. - ✔✔Tocopherols are *more*
prevalent than tocotrienols.
✔✔What form of vitamin E is most potent? - ✔✔alpha-tocopherol
✔✔What is the DRI for vitamin E for adults? - ✔✔15 mg/day (alpha-tocopherol)
✔✔What is the absorption efficiency of vit E? - ✔✔20 - 50%
✔✔Some vitamin E enters the __________ via lipoprotein lipase. - ✔✔Some vitamin E
enters the *body's tissues* via lipoprotein lipase.
✔✔Some can translocate into circulating __________. - ✔✔Some can translocate into
circulating *HDLs*.
✔✔Some vitamin E is released in liver cells where it binds to _____________________.
- ✔✔Some vitamin E is released in liver cells where it binds to *hepatic tocopherol
transfer protein (HTTP)*.
, ✔✔HTTP incorporates vitamin E into __________. - ✔✔HTTP incorporates vitamin E
into *VLDL*.
✔✔What are the primary storage sites for vitamin E? - ✔✔- liver
- adipose tissue
- skeletal muscle
- lipoproteins
✔✔What are the secondary storage sites for vitamin E? - ✔✔- adrenals
- heart
- lungs
- brain
✔✔How is vitamin E excreted from the body? - ✔✔- bile & fecal losses (major route)
- sloughing of enterocytes
- skin secretions, dermal exfoliation
- urinary losses
✔✔Functions of vitamin E - ✔✔- antioxidant for cell membrane integrity
- may exert influence on gene expression
- may decrease heart disease through decreased development of atherosclerotic plaque
- may decrease dementia (900mg alpha-tocopherol)
✔✔How does vitamin E act as an antioxidant? - ✔✔Prevents oxidation of unsaturated
FA components of membrane phospholipids.
✔✔RDA for vitamin E is __________ for adult men and women, using __________ as
the reference isomer. - ✔✔RDA for vitamin E is *15 mg/day* for adult men and women,
using *alpha-tocopherol* as the reference isomer.
- other isomers are not as bioavailable and are not included as part of daily dietary
value.
✔✔Symptoms of vitamin E deficiency: - ✔✔- associated with cellular membrane
degeneration
- destruction of RBC membranes (hemolytic anemia)
- degeneration of neuronal & muscular membranes
- retinal degeration
- Rare and slow to develop, taking up to a year for signs to show. (except if pt has
maldigestion of lipids - cystic fibrosis, celiac disease, hepatic & biliary insufficiency,
imparied lipoprotein production)
✔✔Symptoms of vitamin E toxicity: - ✔✔Relatively nontoxic, but symptoms may include:
AND SOLUTIONS GUARANTEE A+
✔✔Vitamin D becomes part of __________ and then enters the __________
circulation. - ✔✔Vitamin D becomes part of *chylomicrons* and then enters the *lymph*
circulation.
✔✔40% of vitamin D is transported in chylomicrons. The remaining 60% is transported
by what protein? - ✔✔D-binding Protein (DBP)
- this is also the same protein that picks up vitamin D created in the skin
✔✔The efficiency of binding to vitamin D is increased after two ____________. -
✔✔The efficiency of binding to vitamin D is increased after two *hydroxylations*.
✔✔Both the _____ and the _____ add a hydroxyl group to the vitamin D structure. -
✔✔Both the *liver* and the *kidneys* add a hydroxyl group to the vitamin D structure.
✔✔When vitamin D levels are low, what becomes more efficient? - ✔✔25-hydroxylase
✔✔When light hits the skin, what is the pathway for it to become vitamin D? - ✔✔Sun
- skin
-- 7-dehydrocholesterol
--- liver: 1st hydroxylation
---- kidney: 2nd hydroxylation
----- 1, 25(OH)2VitD3
------ Metabolically active form
✔✔What is the most potent vitamin D metabolite? - ✔✔1,25-dihydroxycholecalciferol
✔✔Functions of vitamin D - ✔✔- regulation of gene expression
- affects calcium & phosphate homeostasis
- differentiation of stem cells in bone tissue
- differentiation of hair follicles & skin cells
✔✔AI recommendation for vitamin D in infants to 50yrs - ✔✔5 mcg/day
✔✔AI recommendation for vitamin D in > 50yrs - ✔✔15 mcg/day
✔✔AI recommendation for vitamin D in > 70yrs - ✔✔20 mcg/day
✔✔UL recommendation for vitamin D in > 9yr - ✔✔50-100 mcg
✔✔What diseases are caused by vitamin D deficiency? - ✔✔- Rickets
,- Osteomalacia
✔✔Failure of growing bones to mineralize properly. This results in bowing of long,
weight-bearing bones. - ✔✔Rickets
✔✔Vitamin D deficiency in adults. This results from decreased calcium and phosphate
absorption. aka, soft bones - ✔✔Osteomalacia
✔✔At risk groups for vitamin D deficiency - ✔✔- insufficient sunlight exposure
- aging reduces D synthesis in skin
- fat malabsorption
- anticonvulsant drug therapy
- breast fed infants
- renal disease
✔✔Tocopherols are __________ while tocotrienols are __________. - ✔✔Tocopherols
are *saturated* while tocotrienols are *unsaturated*.
✔✔Food sources of vitamin E - ✔✔- plant oils
- oil derived products
- wheat germ & oil & nuts
- some fruits & vegetables (peaches & asparagus)
- meat & fish
✔✔Tocopherols are ______ prevalent than tocotrienols. - ✔✔Tocopherols are *more*
prevalent than tocotrienols.
✔✔What form of vitamin E is most potent? - ✔✔alpha-tocopherol
✔✔What is the DRI for vitamin E for adults? - ✔✔15 mg/day (alpha-tocopherol)
✔✔What is the absorption efficiency of vit E? - ✔✔20 - 50%
✔✔Some vitamin E enters the __________ via lipoprotein lipase. - ✔✔Some vitamin E
enters the *body's tissues* via lipoprotein lipase.
✔✔Some can translocate into circulating __________. - ✔✔Some can translocate into
circulating *HDLs*.
✔✔Some vitamin E is released in liver cells where it binds to _____________________.
- ✔✔Some vitamin E is released in liver cells where it binds to *hepatic tocopherol
transfer protein (HTTP)*.
, ✔✔HTTP incorporates vitamin E into __________. - ✔✔HTTP incorporates vitamin E
into *VLDL*.
✔✔What are the primary storage sites for vitamin E? - ✔✔- liver
- adipose tissue
- skeletal muscle
- lipoproteins
✔✔What are the secondary storage sites for vitamin E? - ✔✔- adrenals
- heart
- lungs
- brain
✔✔How is vitamin E excreted from the body? - ✔✔- bile & fecal losses (major route)
- sloughing of enterocytes
- skin secretions, dermal exfoliation
- urinary losses
✔✔Functions of vitamin E - ✔✔- antioxidant for cell membrane integrity
- may exert influence on gene expression
- may decrease heart disease through decreased development of atherosclerotic plaque
- may decrease dementia (900mg alpha-tocopherol)
✔✔How does vitamin E act as an antioxidant? - ✔✔Prevents oxidation of unsaturated
FA components of membrane phospholipids.
✔✔RDA for vitamin E is __________ for adult men and women, using __________ as
the reference isomer. - ✔✔RDA for vitamin E is *15 mg/day* for adult men and women,
using *alpha-tocopherol* as the reference isomer.
- other isomers are not as bioavailable and are not included as part of daily dietary
value.
✔✔Symptoms of vitamin E deficiency: - ✔✔- associated with cellular membrane
degeneration
- destruction of RBC membranes (hemolytic anemia)
- degeneration of neuronal & muscular membranes
- retinal degeration
- Rare and slow to develop, taking up to a year for signs to show. (except if pt has
maldigestion of lipids - cystic fibrosis, celiac disease, hepatic & biliary insufficiency,
imparied lipoprotein production)
✔✔Symptoms of vitamin E toxicity: - ✔✔Relatively nontoxic, but symptoms may include:
