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Flashcards in Exam 2: Vitamins Deck (158)
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1
Q

Vitamins were first discovered while

A

Searching for cures for common diseases

2
Q

What happened in 1906

A

Found that a diet of synthetic protein, fat, and carbs killed all rats that were fed it but adding milk was enough to maintain normal growth

3
Q

In 1911

A

A chemist found an amine that he thought might be a common characteristic of all tiny required compounds
- called it a “Vital Amine”

4
Q

All Vitamins are

A
  1. Organic compounds different than Carbs, lipids, and proteins
  2. natural components found in food
  3. Essential (required for normal function)
  4. Specific deficiency caused by lack of adequate amounts
5
Q

Vitamins are required in

A

Small amounts; milligram or micrograms

6
Q

All vitamins function as

A
  • Membrane stabilizers
  • Proton and electron donor and acceptors
  • Hormones
  • Coenzymes
7
Q

Diseases caused by clinical deficiency

A
  1. Pellagra
  2. Burning feet syndrome
  3. Keshan’s disease
8
Q

Subclinical deficiency is associated with

A

Increased risk of chronic diseases

HTN, atherosclerosis, CA

9
Q

Fat soluble vitamins are absorbed as

A

Part of micelles

10
Q

What enhances fat-soluble vit. Absorption

A

Fat intake

11
Q

Vitamins more likely to be toxic

A

Fat-soluble vitamins (stored in liver and adipose)

12
Q

Fat soluble vitamins are transported

A

In lipoproteins in the lymphatic system

13
Q

Water soluble vitamins are transported by

A

Portal vein

14
Q

Vitamins that are not stored in large quantities

A

Water-soluble

  • less likely to become toxic bc they aren’t stored
  • must rely on daily intake to meet requirements
15
Q

Vitamin A is a ______ vitamin

A

Fat-soluble

16
Q

Main function of retinol

A

Reproduction and growth

17
Q

Main function of Retinal

A

Vision

18
Q

Main function of retinoic acid

A

Cell differentiation (*Most important function of vitamin A)

19
Q

Preformed Vit A is found in

A
  • Liver, fish, and added to dairy

- Retinol esters (retinol with a FA attached)

20
Q

Retinol Palmitate is a ____ ______ that functions as

A

Retinol ester; storage form of vit A

21
Q

Proformed versions of Vit A

A

Orange, yellow, and red colored plants

22
Q

Carotenoids are found in

A

Plant sources; only used when we don’t get enough from preformed sources

23
Q

Preformed to Proformed ratio of Vitamin A

A

12X as much proformed to equal preformed activity

24
Q

There are _______ known carotenoids; but only ______ can be converted to ______

A

> 600, <10%, retinol

25
Q

Beta-carotene requires ______ as much to get to the RDA of retinol

A

12X

26
Q

Lycopene requires _____ as much to get to appropriate level of retinol

A

24X

27
Q

Retinal is part of _____ and functions in ____

A

Rhodopsin; vision

28
Q

Forms of vitamin A that function in protein synthesis and cell differentiation

A

Retinoic acid

29
Q

Retinoic acid and retinol both function to

A

Maintain epithelial tissue

30
Q

A deficiency in what vitamin leads to night blindness?

A

Retinol leads to decrease in rhodopsin

31
Q

Vit highly concentrated in rods of the retina

A

Retinal

32
Q

Retinal + ________= Rhodpsin

A

Opsin

33
Q

Vitamin A turns keritinizing cells into

A

Mucus-secreting cells in the eye, mouth, intestine, lungs, kidneys and reproductive tract

34
Q

Hyperkeratinization

A

When vit a is decreased keratin-producing cells replace mucus-secreting cells in the respiratory, GI, and Urinary tracts

35
Q

Keratinocytes are _____ ____ _____ until they interact with Vit A and then they are ______

A

Immature skin cells; mature epidermal cells

36
Q

Carotenoids are the only form of Vit A to act as

A

Antioxidants

37
Q

Antioxidants

A
  • quench ROS

- Prevents UV- induced eye damage

38
Q

Antioxidants prevent UV-induced eye damage because

A

Lutein and xeaxxanthin are concentrated in the macula

39
Q

Carotenoid Function in cell growth and differentiation

A
  • specific ones may inhibit growth and proliferation of several CAs
  • Supplements increase the risk of several CAs
40
Q

What form of Vit A do we get mostly from animal products?

A

Retinol

41
Q

Carotenoids are found in

A

Yellow, orange, and dark green plants

42
Q

Carotenoids consist of 2 things

A

carotenes (no oxygen) and xanthophylls (contain oxygen; Lutein)

43
Q

Vit A’s RDDA is measured as

A

Retinol Activity Equivalents (RAE)

44
Q

Storage of vit a

A

Liver stores 70% of the body’s total

- toxicity may cause liver damage

45
Q

Vit A is toxic if

A

We don’t bind it

46
Q

Vit A Deficiency AKA

A

Hypovitaminosis A

47
Q

Primary and secondary causes of vit A def.

A
  1. Inadequate intake (in the world, not US)

2. Fatty malabsorption (problem in US)

48
Q

Causes of fatty malabsorption

A
  • inadequate fat intake
  • bile or pan created enzyme insufficiency
  • liver disease
  • zinc deficiency
  • protein-energy malnutrition
49
Q

Vision problems caused by vit A deficiency

A
  • Night blindness
  • Xerosis
  • Xerophthalmia
  • Bitot’s spots
  • Permanent blindness (in developing countries)
50
Q

Xerosis

A

Itching, burning of eyelid

51
Q

Xerophthalmia

A

Dry eye from inadequate mucus production

52
Q

Bitot’s spots are

A

Keratin deposition in the eye

53
Q

Leading cause of preventable blindness in children

A

Vit A deficiency

54
Q

Vit A deficiency leads to a _____ immune system and ______ on skin

A

Depressed; follicular hyperkeratosis caused by plugs of keratin (looks like goosebumps)

55
Q

Hypervitaminosis A

A

Vitamin A toxicity

56
Q

Only ____ vitamin A can cause toxicity

A

Preformed (not carotenoids)

57
Q

Vit A toxicity can cause

A

Bone pain (fractures), dry skin, hair loss, fatigue, anorexia, and liver damage

58
Q

Excessive Vit A intake during pregnancy is ______ and _____ should not be used during or soon before pregnancy

A

Teratogenic, accutane

59
Q

Carotenoids are considered _____ toxicity and have ______ TUL set

A

Low, no TUL set

60
Q

Carotenoids are safe in _____ but in supplements they can promote:

A

Safe in plant based foods; in supplements they promote oxidative damage, cell division and destruction of other forms of vit A

61
Q

Supplementation of carotenoids

A

Not recommended

- increased risk of lung cancer, heart disease, and death in smokers and former smokers

62
Q

Examples of proformed vit A

A
  • Carrots
  • Dark green leafy veggies
  • Sweet potatoes
  • tomatoes
  • Cantaloupe
63
Q

Vit A is unstable when ___________, it’s best to cook it ________

A

Unstable when exposed to heat and oxygen, best to cook quickly with little water

64
Q

Requirements for vitamin A absorption

A

Emulsification by bile salts

65
Q

Vit A is absorbed via _____ in the ____ and _____

A

Passive diffusion, in duodenum and jejunum

66
Q

Bioavailability of Vit A

A

Preformed: 75-100%
Proformed: 3-90% (increased by cooking)

67
Q

Which vitamin has the greatest bioavailability

A

Vitamin A

68
Q

Retinol is bound by _______ and resertfied to a RE in the enterocyte by ______

A

Cellular-retinol binding protein (CRBP); lecithin (LRAT)

69
Q

The RE is incorporated into

A

Chylomicrons and transported in the lymphatic system

70
Q

A vitamin is a _____ nutrient

A

Organic

71
Q

What is the minimum amount of fat required for Vit A to be absorbed?

A

5-10g

72
Q

Which hormone causes the gallbladder to contract?

A

Cholecystokinin

73
Q

How much proformed Vit A is required compared to preformed vitamin A?

A

12

74
Q

Deficiency of what mineral will not lead to a vitamin A deficiency?

A

Copper

75
Q

What form of Vit A is part of Rhodopsin?

A

Retinal

76
Q

Does Preformed vit A have antioxidant activity?

A

No

77
Q

What is the primary cause of hypovitaminosis A?

A

Inadequate vitamin A intake

78
Q

Animal form of vitamin D

A

Cholecalciferol (D3)

79
Q

Plant form of Vit D

A

Ergocalciferol (D2)

80
Q

Cholecalciferol is made from _____ and has a half life of

A

Cholesterol; 82 days

81
Q

Ergocalciferol has a half life of

A

33 days

82
Q

Vitamin D is a ______ not a vitamin

A

Prohormone

83
Q

What biomarker should be used to check vitamin D levels?

A

25-hydroxyvitamin D3 (inactive)

84
Q

Vitamin Ds main function

A

Maintain blood calcium levels

85
Q

Vitamin D acts like a _____ hormone and affects gene expression

A

Steroid

86
Q

Vit D ________ absorption in the small intestine and _____ renal reabsorption

A

Increases; increases

87
Q

Vit D stimulates ___________

A

Mobilization from trabecular bone if needed (bone mineralization)

88
Q

Vitamin D ____________ influence PTH release

A

Does NOT

89
Q

Vit D recommendations for infants (lesss than 1 year)

A

400 IU

90
Q

Vit D recommendations for kids/adults (1-70 years)

A

600 IU

91
Q

Vit D. Recommendation for older adults (>70)

A

800 IU

92
Q

Steps from Ca to PTH to Vit D to Proteins

A
  • Low blood calcium causes PTH to be secreted
  • PTH induces hydroxylase in kidneys
  • Hydroxylase activates calcitriol
  • Calcitriol stimulates synthesis of Ca-binding proteins
  • Ca-binding proteins increase Ca absorption and decrease Ca excretion
93
Q

Vit D Reequirements Vary due to:

A
  • Season (inadequate October-April)
  • Latitude (less made above 35-40 degrees)
  • Skin color (Melanin prevents synthesis)
  • Sunscreen
  • Age (70 year olds synthesize 75% less)
  • Malabsorptive conditions
  • Obesity
94
Q

Hypovitaminosis D causes _________ bones that results in _____ in children and ______ in adults

A

Soft, spongy

Rickets, osteomalacia

95
Q

Hypovitaminosis D causes

A
  • bone weakness
  • autoimmune conditions (RA, MS, IBD)
  • Myopathy
  • Diabetes
  • Depression, Alzheimer’s Schizophrenia, anxiety
  • Solid cancers (prostate, colon, stomach, breast, liver, kidney)
  • HTN, atherosclerosis, metabolic syndrome
  • Respiratory tract infections
  • Loss of balance
96
Q

Deficiency of Vitamin D is considered a serum level

A

Less than 20 ng/mL

97
Q

It is estimated that ________of Americans are deficient in vitamin D

A

50%

98
Q

Issues don’t arise with vitamin D toxicity until a daily dose of _______ IU has been taken for more than _____

A

10,000 IU; more than 6 months

99
Q

Vit D toxicity causes

A

Hypercalcemia and hyperphosphatemia

-calcification of soft tissues (kidney, lungs, heart)

100
Q

There have been ______ documented cases of toxicity from excessive sunlight

A

No

101
Q

Vit D found in all cells

A

24-hydroxylase

102
Q

Vit D is found in high concentration in the

A

Kidneys

103
Q

Vit D limits amount of

A

Active calcitriol

104
Q

Vid D forms

A

1,24,25- (OH)3D

105
Q

Mutations in gene coding for __________ leads to hypercalcemia

A

24-hydroxylase

106
Q

Vit D supplementation should be cautioned in people with

A
  • Hyperparathyroidism
  • Granulomatous disorders (sarcoidosis, tuberculosis)
  • Some lymphomas
107
Q

Good sources of vitamin D

A

fish liver oils, salmon, mackerel, tuna, fortified dairy, egg yolk

108
Q

Poor sources of vit D

A

Breast milk, unfortified dairy

109
Q

Vitamins D is most stable with

A

Heat, age, and storage

110
Q

Precursor for endogenously produced vitamin D

A

Cholesterol

111
Q

What organ does enzyme alpha-1-hydroxylase convert hydroxylase vitamin D3 to its fully active form

A

Kidney

112
Q

How does vit D increase calcium absorption?

A

Induces synthesis of calcium-binding protein

113
Q

Who could end up with vit D toxicity?

A

Supplement users

114
Q

Vitamin discovered necessary for animal reproduction (especially in rats)

A

Vitamin E

115
Q

Vitamin E is a potent antioxidant because

A

Of donating hydrogens

116
Q

Most common vit E

A

Alpha tocopherol

117
Q

Vitamin E functions as an _______ found in ____ ______

A

Antioxidant; plasma membranes

118
Q

How does vit. E function as an antioxidant?

A

Donates H to free radicals to protect PUFA in membrane

119
Q

_________ of vit E is important because we don’t get enough of it

A

Regeneration

120
Q

“Vitamin _____ is the key to vitamin _____”

A

C is the key to E

121
Q

Only the _____ form of vitamin E acts an an antioxidant

A

Reduced

122
Q

Hypovitaminosis E is

A

Rare

123
Q

Vitamin E deficiency is a deficiency of ______ and symptoms include:

A

Tocopherols

Hemolytic anemia (in infants), neuropathy, retinopathy

124
Q

People at risk for hypovitaminosis E

A

Patients with fat malabsorption disorders and premature infants

125
Q

Too much vitamin E can ____ blood and cause ____ _____

A

Thin blood; nose bleeds

-inhibits vit. K activity and increases bleeding and impaired bone mineralization

126
Q

Vitamin E toxicity

A
  • No known toxicity from food

- Supplements of vit. E inhibit Vitamin K activity

127
Q

Best source of vitamin E

A

Plant oils

128
Q

High alpha tocopherol sources:

A

Olive oil, sunflower oil, safflower oil, cottonseed oil, almonds, peanuts

129
Q

High gamma-tocopherol sources

A

Canola oil, soybean oil, corn oil, seasame oil, walnuts

*midwestern oils

130
Q

High tocotrienol sources

A

Oats, rye, barley, rice bran oil, wheat germ, palm oil

  • found in the germ (oil) of whole grains
131
Q

Natural vitamin. E is

A

Only biologically active isomers present

132
Q

Synthetic vit E has a ________ attached and is a _______ mixture of ______

A

Fatty acid attached

Race is mixture of isomers

133
Q

Vitamin E supplements

A

Alpha-tocopherol only

134
Q

Natural vitamin E is a mixture of

A

Tocopherols and tocotrienols

135
Q

Vit E supplements _____ _____ prevent cancer, heart disease, all cause-mortality, etc.

A

Do not

136
Q

Vitamin E is made unstable with _____ and _____

A

Heat and basic pH

137
Q

What is the function of vitamin E?

A

Antioxidant

138
Q
Which is a good source of Vit E?
A. Milk
B. Ground Beef
C. Almonds
D. Dark leafy greens
A

C. Almonds

139
Q

Vitamin K AKAs

A

Phylloquinone (K1)= green plants

Menaquinone (K2)= bacteria/ animal products

140
Q

Vit K functions in

A

Clotting and bone formation

141
Q

Vit K function

A

Coenzyme

142
Q

Vit K adds a carboxylic acid group to ________ residues in specific proteins to make _______

A

Glutamate; carboxyglutamates (for bone synthesis)

143
Q

Caboxyglutamates are ____ _____ sites

A

Calcium-binding

144
Q

Vit K coenzyme is found on

A

Clotting factors (VII, IX, and X)
Prothrombin
Osteocalcin (secreted by osteoblasts)

145
Q

Vit K function in bone formation

A

Osteoclacin synthesis is stimulated by vitamin D and carboxylated by vit K to facilitate calcium binding

146
Q

Risk for vit K deficiency

A
  • Newborns (w/o shot at birth)
  • Patients with fat malabsorption disorders
  • Patients chronically treated with antibiotics
147
Q

Vit K deficiency causes

A

Increased bleeding (brain bleed in babies), poor bone growth

148
Q

Synthetic ______ is toxic in infants and can cause jaundice

A

Menadione (banned in the 60s)

149
Q

Vit K toxicity

A

No toxicity symptoms from food or current supplements

150
Q

Sources of phylloquinones

A

Broccoli, dark green leafy veggies, kiwi, peas, beans, oils (rapeseed, soybean, olive), margarine

151
Q

Vit K is made unstable by

A

Light and irradiation

152
Q

Which fat-soluble vitamins require digestion prior to absorption?

A

A and E

153
Q

Vit K is a coenzyme for formation of

A

Carboxygluatmates

154
Q

Carboxyglutamates facilitate binding of

A

Calcium

155
Q

Calcium-bound carboxyglutamates are important for ______ and _____

A

Clotting; bone formation

156
Q

Which vitamins are required for normal bone formation?

A

Calcitriol and phylloquinone

157
Q

Which vitamins act as antioxidants in Vivo?

A

Beta-carotene and alpha-tocopherol

158
Q

Know Fat soluble vitamin summary

A

Slide 97