Kansas State University FNDH 620 - Final Exam 2022
(COMPLETE SOLUTIONS)
True or False
Vitamins:
- cannot be made in the body
- noncaloric
- required in small amounts (mg and mcg) Correct Answer: TRUE
Vitamins:
- cannot be made in the body
- noncaloric
- required in small amounts (mg and mcg)
What 3 forms can vitamin A take? Correct Answer: - retinol (alcohol)
- retinal (aldehyde)
- retinoic acid (acid form from retinal)
What form of vitamin A is normally found in blood and tissues? Correct Answer: Retinyl
Palmitate
What form of vitamin A is found in plants? Correct Answer: Previtamin A - carotenoid structure
that includes the carotenes and xanthophylls
- found in plants
- needs to be converted to active vitamin A
What is the most potent form of vitamin A? Correct Answer: Beta carotene
Where can retinyl esters be found? Correct Answer: Animal Products *only*
Where can vitamin A be found? Correct Answer: Fortified milk and milk products
Where can previtamin A carotenoids be found? Correct Answer: Plant sources - orange and dark
green vegetables
Vitamin A containing micelles form and traverse the enterocyte plasma membrane by what type
of diffusion? Correct Answer: Passive Diffusion
What two things are needed in the digestion of vitamin A? Correct Answer: Bile and Fat
Beta-carotene and other carotenoids can be converted to retinol by what means? Correct Answer:
Beta-carotene and other carotenoids can be converted to retinol by cleavage of the central double
bond
,When beta-carotene is cleaved, how many molecules of retinal does it make? Correct Answer: 1
beta-carotene = 2 retinal
Retinyl, retinyl esters, and carotenoids are packaged into what and transported where? Correct
Answer: Retinyl, retinyl esters, and carotenoids are packaged in *chylomicrons* and transported
in the *lymphatic system*.
Vitamin A and carotenoids are metabolized where and as what? Correct Answer: Vitamin A and
carotenoids are metabolized in the liver as chylomicron remnants.
Retinoic acid is absorbed and transported to which organ bound to what protein? Correct
Answer: Retinoic acid is absorbed and transported to the liver bound to albumin.
The liver stores 90% of which vitamin? Correct Answer: vitamin A
What are the functions of vitamin A & Carotenoids? Correct Answer: - Improves vision
- Cell differentiation & cell proliferative activity
- Fights cancer
- Development of embryo tissue
- Synthesis of glycoproteins
- Reproductive processes
- Antioxidant capacity
- Bone development and maintenance
- Provides immunity
How is vitamin A essential to our vision? Correct Answer: - retinol is transformed into 11-cis
retinal through a series of reactions
- 11-cis retinal combines with the protein opsin forming rhodopsin
- Rhodopsin + light changes the conformation of the protein which begins a cascade of events
leading to the generation of an action potential
- This action potential sends neural impulses to the optic center of the brain translating it into
images
What are the 2 nuclear receptors that work with vitamin A on a molecular level? Correct
Answer: RAR & RXR
Vitamin A is beneficial for all cancers but... Correct Answer: lung cancer
Vitamin A is involved in sperm development and differentiation, without it, what happens?
Correct Answer: Without RARγ, males are sterile
If a female is low or deficient in vitamin A, what could happen? Correct Answer: deficiency:
inability of implantation of the egg
low: may allow implantation but may end in a miscarriage; various birth defects
,Vitamin A is excreted in _____ & _____. Correct Answer: Vitamin A is excreted in the bile
(70%) and urine (30%).
RDA of vitamin A for men Correct Answer: 900 mcg/day
RDA of vitamin A for women Correct Answer: 700 mcg/day
12 mcg beta-carotene = ??? mcg of retinol Correct Answer: 12 mcg beta-carotene = 1 mcg of
retinol
Vitamin A deficiency is the leading cause of ___________ in children worldwide. Correct
Answer: Vitamin A deficiency is the leading cause of *non-accidental blindness* in children
worldwide.
Diseases caused by vitamin A deficiency Correct Answer: - night blindness
- xerophthalmia
- bitot spots
Symptoms of vitamin A toxicity Correct Answer: - decreased appetite
- dry, itchy, flaky skin
- headache
- hair loss
- bone/muscle pain
- ataxia
- nausea/vomiting
- dry mouth
- eye irritations
- conjunctivitis
- birth defects
- miscarriage
- learning difficulities
This unique vitamin is synthesized in the body with adequate sun exposure as well as it's ability
to function as a hormone. Correct Answer: Vitamin D
What are the two forms of vitamin D? Correct Answer: D2 - ergocalciferol
D3 - cholecalciferol
UV light converts __________ into cholecalciferol (D2). Correct Answer: UV light converts *7-
dehydrocholesterol* into cholecalciferol (D2).
Aside from humans being able to produce their own amounts of vitamin D, it can also be found
in: Correct Answer: - animal foods (eggs, liver, fatty fish, & butter)
- fortified milk and dairy products
- fortified margarine
, Vitamin D enters mucosal enterocytes by __________ diffusion. Correct Answer: Vitamin D
enters mucosal enterocytes by *passive* diffusion.
Vitamin D becomes part of __________ and then enters the __________ circulation. Correct
Answer: 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? Correct Answer: 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 ____________. Correct Answer:
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. Correct Answer:
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? Correct Answer: 25-hydroxylase
When light hits the skin, what is the pathway for it to become vitamin D? Correct Answer: 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? Correct Answer: 1,25-dihydroxycholecalciferol
Functions of vitamin D Correct Answer: - 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 Correct Answer: 5 mcg/day
AI recommendation for vitamin D in > 50yrs Correct Answer: 15 mcg/day
AI recommendation for vitamin D in > 70yrs Correct Answer: 20 mcg/day
UL recommendation for vitamin D in > 9yr Correct Answer: 50-100 mcg
What diseases are caused by vitamin D deficiency? Correct Answer: - Rickets
- Osteomalacia
(COMPLETE SOLUTIONS)
True or False
Vitamins:
- cannot be made in the body
- noncaloric
- required in small amounts (mg and mcg) Correct Answer: TRUE
Vitamins:
- cannot be made in the body
- noncaloric
- required in small amounts (mg and mcg)
What 3 forms can vitamin A take? Correct Answer: - retinol (alcohol)
- retinal (aldehyde)
- retinoic acid (acid form from retinal)
What form of vitamin A is normally found in blood and tissues? Correct Answer: Retinyl
Palmitate
What form of vitamin A is found in plants? Correct Answer: Previtamin A - carotenoid structure
that includes the carotenes and xanthophylls
- found in plants
- needs to be converted to active vitamin A
What is the most potent form of vitamin A? Correct Answer: Beta carotene
Where can retinyl esters be found? Correct Answer: Animal Products *only*
Where can vitamin A be found? Correct Answer: Fortified milk and milk products
Where can previtamin A carotenoids be found? Correct Answer: Plant sources - orange and dark
green vegetables
Vitamin A containing micelles form and traverse the enterocyte plasma membrane by what type
of diffusion? Correct Answer: Passive Diffusion
What two things are needed in the digestion of vitamin A? Correct Answer: Bile and Fat
Beta-carotene and other carotenoids can be converted to retinol by what means? Correct Answer:
Beta-carotene and other carotenoids can be converted to retinol by cleavage of the central double
bond
,When beta-carotene is cleaved, how many molecules of retinal does it make? Correct Answer: 1
beta-carotene = 2 retinal
Retinyl, retinyl esters, and carotenoids are packaged into what and transported where? Correct
Answer: Retinyl, retinyl esters, and carotenoids are packaged in *chylomicrons* and transported
in the *lymphatic system*.
Vitamin A and carotenoids are metabolized where and as what? Correct Answer: Vitamin A and
carotenoids are metabolized in the liver as chylomicron remnants.
Retinoic acid is absorbed and transported to which organ bound to what protein? Correct
Answer: Retinoic acid is absorbed and transported to the liver bound to albumin.
The liver stores 90% of which vitamin? Correct Answer: vitamin A
What are the functions of vitamin A & Carotenoids? Correct Answer: - Improves vision
- Cell differentiation & cell proliferative activity
- Fights cancer
- Development of embryo tissue
- Synthesis of glycoproteins
- Reproductive processes
- Antioxidant capacity
- Bone development and maintenance
- Provides immunity
How is vitamin A essential to our vision? Correct Answer: - retinol is transformed into 11-cis
retinal through a series of reactions
- 11-cis retinal combines with the protein opsin forming rhodopsin
- Rhodopsin + light changes the conformation of the protein which begins a cascade of events
leading to the generation of an action potential
- This action potential sends neural impulses to the optic center of the brain translating it into
images
What are the 2 nuclear receptors that work with vitamin A on a molecular level? Correct
Answer: RAR & RXR
Vitamin A is beneficial for all cancers but... Correct Answer: lung cancer
Vitamin A is involved in sperm development and differentiation, without it, what happens?
Correct Answer: Without RARγ, males are sterile
If a female is low or deficient in vitamin A, what could happen? Correct Answer: deficiency:
inability of implantation of the egg
low: may allow implantation but may end in a miscarriage; various birth defects
,Vitamin A is excreted in _____ & _____. Correct Answer: Vitamin A is excreted in the bile
(70%) and urine (30%).
RDA of vitamin A for men Correct Answer: 900 mcg/day
RDA of vitamin A for women Correct Answer: 700 mcg/day
12 mcg beta-carotene = ??? mcg of retinol Correct Answer: 12 mcg beta-carotene = 1 mcg of
retinol
Vitamin A deficiency is the leading cause of ___________ in children worldwide. Correct
Answer: Vitamin A deficiency is the leading cause of *non-accidental blindness* in children
worldwide.
Diseases caused by vitamin A deficiency Correct Answer: - night blindness
- xerophthalmia
- bitot spots
Symptoms of vitamin A toxicity Correct Answer: - decreased appetite
- dry, itchy, flaky skin
- headache
- hair loss
- bone/muscle pain
- ataxia
- nausea/vomiting
- dry mouth
- eye irritations
- conjunctivitis
- birth defects
- miscarriage
- learning difficulities
This unique vitamin is synthesized in the body with adequate sun exposure as well as it's ability
to function as a hormone. Correct Answer: Vitamin D
What are the two forms of vitamin D? Correct Answer: D2 - ergocalciferol
D3 - cholecalciferol
UV light converts __________ into cholecalciferol (D2). Correct Answer: UV light converts *7-
dehydrocholesterol* into cholecalciferol (D2).
Aside from humans being able to produce their own amounts of vitamin D, it can also be found
in: Correct Answer: - animal foods (eggs, liver, fatty fish, & butter)
- fortified milk and dairy products
- fortified margarine
, Vitamin D enters mucosal enterocytes by __________ diffusion. Correct Answer: Vitamin D
enters mucosal enterocytes by *passive* diffusion.
Vitamin D becomes part of __________ and then enters the __________ circulation. Correct
Answer: 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? Correct Answer: 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 ____________. Correct Answer:
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. Correct Answer:
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? Correct Answer: 25-hydroxylase
When light hits the skin, what is the pathway for it to become vitamin D? Correct Answer: 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? Correct Answer: 1,25-dihydroxycholecalciferol
Functions of vitamin D Correct Answer: - 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 Correct Answer: 5 mcg/day
AI recommendation for vitamin D in > 50yrs Correct Answer: 15 mcg/day
AI recommendation for vitamin D in > 70yrs Correct Answer: 20 mcg/day
UL recommendation for vitamin D in > 9yr Correct Answer: 50-100 mcg
What diseases are caused by vitamin D deficiency? Correct Answer: - Rickets
- Osteomalacia
