Exam 2: Water-Soluble Vitamins Flashcards
(199 cards)
1
Q
Vitamin C functional form
A
Ascorbic acid
2
Q
Vitamin C is nonessential for
A
Most animals and plants (made from glucose and galactose)
3
Q
Vitamin C IS essential for
A
Humans, primates, fruit bats, guinea pigs and some birds
4
Q
Vitamin C function in connective tissue
A
- Required for collagen synthesis
- necessary for hydroxylation of proline and lysine
5
Q
Vitamin C is a coenzyme for
A
More metabolically active tissues (adrenals, brain, liver, pancreas)
6
Q
Vit C is required for conversion of _____ to _____, synthesis of _______, metabolism of ________ and absorption of ________
A
Dopamine to norepinephrine, synthesis of carnitine, metabolism of folate and tryptophan, absorbs non-heme iron
7
Q
Vitamin C acts as an____ and can regenerate
A
Antioxidant, regenerate vitamin E
Can donate 2 hydrogens
8
Q
Proline to Hydroxyproline requires
A
Vitamin C and iron via proline hydroxylase
9
Q
Lysine to hydroylysine requires
A
Vitamin C and iron via lysyl hydroxylase
10
Q
RDA for Vitamin C
A
Men= 90 mg Women= 75 mg Smokers= RDA + 35 mg
11
Q
Smokers require more vitamin C because of
A
Free radicals
12
Q
Characteristics of Vitamin C deficiency
A
Easy bruising Pinpoint Hemorrhages Bone fracture Poor wound healing Bleeding gums Tooth loss Scurvy
13
Q
4 Hs of Scurvy
A
Hemorrhagic signs (poor wound healing)
Hyperkeratosis of hair follicles
Hypochondriasis (psychological)
Hematologic (impaired collagen synthesis and decreased iron absorption)
14
Q
Scurvy can be found in people with
A
Poor diet, alcoholism, or drug habits
15
Q
Must consume ______ vitamin C to prevent scurvy
A
10 mg/ day
16
Q
Sources of vitamin C
A
- Bell peppers
- Citrus fruits and fruit juices
- Broccoli
- Dark green leafy veggies
17
Q
Vitamin C is unstable due to
A
Oxygen, heat, and basic pH (baking soda destroys)
18
Q
Cooking effects on vitamin C
A
- easily extracted in water
- prepared veggies refrigerated for 24 hours has lost about 50% of the vitamin C
- Frozen often contains more vit C than fresh
19
Q
Thiamin functions
A
Coenzyme (TDP or TPP)
Noncoenzyme (TTP)
20
Q
Thiamin as a coenzyme
A
- energy production (used by dehydrogenase)
- NADPH and pentode synthesis (part of transketolase)
21
Q
Thiamin functions as a noncoenzyme in
A
Nervous system
- regulates sodium channels and chloride transport in nerve transduction
22
Q
Thiamin requirements
A
Men- 1.2 mg
Women- 1.1 mg
23
Q
Organs target by thiamin deficiency
A
Peripheral nerves, heart and brain
24
Q
Thiamin sources
A
Yeast Pork Whole grains Enriched grains Legumes
25
Thiamin deficiency in nerves, heart, and the brain causes
In Peripheral nerves- numbing and paralysis
Heart- edema and fatigue
Brain- decreased alertness
26
Chronic thiamin deficient is called
Beriberi
27
Populations where beriberi is common
Where diet mostly consists of polished rice
28
Dry Beriberi
- low thiamin and high carb intake
| - muscle weakness, extremity wasting, peripheral neuropathy, tender calf muscles
29
Wet beriberi
- enlarged heart, rapid heart beat, peripheral edema, high BP
30
Acute beriberi
- chronic infant deficiency (2-5 months)
- breastfed by mothers with poor thiamin intake
- anorexia, nausea, vomiting, lactic acidosis
31
Chronic thiamin deficiency in alcoholics
Wernicke- Korsakoff Syndrome
32
Chronic thiamin deficiency in alcoholics results in
Decreased thiamin intake
Decreased thiamin absorption
Increased thiamin utilization
33
Most common nutritional deficiency in alcoholics
Thiamin
34
TUL of thiamin
None
35
Raw seafood contains ______ which
Thiaminases; degrades thiamin... bad source
36
Which disorder is only due to a dietary deficiency of thiamin
Acute beriberi
37
Dry beriberi consists of low thiamin intake and
High carbohydrate intake; therefore need to eat more thiamin
38
Symptoms of Wernicke- Korsakoff syndrome
Psychosis/ delirium
ataxia of gait and stance, anorexia
Vomiting
Enlarged heart
39
Thiamin toxicity is rare but problems could be caused when:
100X the RDA is given by IV
| -causes headache, convulsions, cardiac arrhythmia, anaphylactic shock
40
Thiamin instability is caused by
Neutral or basic pH that occurs in water during cooking
41
Riboflavin coenzymes
FAD and FMN
42
FAD and FMN coenzyme functions
- Flavin ring important for redox reactions
- Found in ETS for dehydrogenases and 1st step in beta-oxidation and Krebs
- Synthesis of niacin, folate, and B6
- Converts retinal to retinoic acid
43
Requirements of riboflavin
```
Men= 1.3 mg
Women= 1.1 mg
```
44
Riboflavin Deficiency happens after
Several months of deficient intake
45
Riboflavin deficiency causes
Photophobia
Burning and itching eyes
Soreness of mouth (cheilosis, angular stomatitis, glossitis & magenta tongue)
46
Severe riboflavin deficiency inhibits
Vitamin B6 and NAD synthesis
*B vitamin deficiencies can have similar signs
47
Magenta tongue differentiates
Ariboflavinosis vs any other b vitamin deficiency
48
Riboflavin deficiency causes
Ariboflavinosis
49
400 mg of riboflavin can help treat
Migraines with no side effects
50
Riboflavin sources
- cow’s milk
- enriched grains
- almonds
- soybeans
- eggs
- meats
51
Riboflavin instability is caused by
Light and water during cooking
52
Niacin coenzymes
NAD and NADP
53
NAD and NADP are coenzymes for >200 enzymes that are mostly
Dehydrogenases
54
Most common nutritional deficiency in alcoholics
Thiamin
55
Vit C is required for what posttranslational modification in collagen synthesis?
Hydroxylation q
56
A male smoker should consume how much vitamin C daily?
125 mg
110- female smoker
57
Which is NOT one of the 4 H’s of scurvy?
1. Hyperkeratosis
2. Hypertension
3. Hematologic
4. Hypochondriasis
2. Hypertension
58
T/F there is no tolerable upper intake level set for vit. C?
False
59
TTP is used in
Na+/Cl- transport
60
A good source of thiamin
Grilled pork chops
61
Disorder due to a dietary deficiency only
Dry Beriberi
62
Dry beriberi causes
Tense calf muscles
63
Symptoms seen with Ariboflavinosis near the mouth
Cheilosis
Angular stomatitis
Glossitis and MAGENTA TONGUE
64
Other Ariboflavinosis symptoms
Photophobia and corneal vascularization
Seborrheic dermatitis
Anemia
Peripheral neuropathy
65
NAD and NADPH function as _ ______ in redox reactions
H acceptors
66
NAD
Used in glycolysis, Krebs cycle, beta oxidation, and ethanol metabolism
67
NADPH
Used in fatty acid synthesis, cholesterol synthesis, and folate synthesis
68
Most of our niacin comes from
Tryptophan
69
60 mg tryptophan =
1 mg niacin
70
Pellagra was discovered by
Dr. Joseph Goldberger
71
3 D’s of Pellagra
Dermatitis
Dementia
Diarrhea
*DEATH
72
Dermatitis associated with pellagra looks like a _____ on face, neck, and extremities
Sunburn.
73
Dementia symptoms associated with Pellagra
Headache, memory loss, confusion, disorientation
74
Diarrhea is caused during Pellagra because of
Digestive abnormalities causing inflammation of mucus membrane of mouth and GI tract (glossitis, cheilosis, angular stomatitis)
75
Pellagra is caused by a _____ or _______ deficiency
Niacin or tryptophan
76
Pellagra is common where ______ is a staple in the diet
Corn
77
Pellagra is often found with ________
Ariboflavinosis
| Having Ariboflavinosis causes Pellagra because you make niacin from tryptophan and tryptophan needs riboflavin
78
Niacin Toxicity
- No toxicity from dietary sources
| - Gram doses can lower Triglycerides and LDL and raise HDL
79
Side effects of using Nicotinic Acid to lower TGs and LDL and raise HDL
Vasodilation (flushing from histamine), heartburn, liver damage, gout, impaired blood glucose
80
Sources of Niacin
```
Enriched cereals
Chicken
Fish
Pork
Beef
Peanuts
Yeast
```
81
Niacin instability is caused by
A basic pH and water during cooking
82
Vit B6 Functions as a
Coenzyme (PLP)
83
Pyridoxal Phosphate AKA
Vit B6
84
PLP is required for
```
Amino acid metabolism
Synthesis of heme
Sphingolipids in myelin sheath
Steroids
Niacin
Neurotransmitters
Histamine
```
85
Vitamin B6 requirements vary depending on
Protein intake (more protein, more B6 needed)
86
B6 deficiency is ____ and symptoms include:
Rare;
Dermatitis, glossitis, cheilosis, stomatitis, seizures
* Peripheral Neuropathy
* Hypochromic Microcytic Anemia
87
Hypochromic Microtyic Anemia is caused by a
Lack of heme synthesis
88
B6 toxicity causes
Nerve damage
89
B6 has a higher bioavailability from ______ than ____
Animal than plant
90
Sources of B6
- enriched grains
- meats
- nuts
- grains
91
B6 becomes unstable in
- basic pH
- Light
- water during cooking
92
Folium means
Leaf
93
Folate is B___
B9
94
Synthetic form of Folate
Folic acid
95
Folic acid is the _______ stable form of folate
Most stable; does. Not require digestion and is absorbed 100%
96
Folate contains _____ ____. _____ which are removed by _____ in the brush border
Glutamic acid residues; conjugate
97
Conjugase is a ____ dependent enzyme
Zinc
98
Conjugase inhibitors
Legumes, oranges, cabbage, chronic alcohol consumption
99
Folate functions as enzymes
Tetrahydrofolate, THF or TH4
100
Folate as an enzyme
- Donor and acceptor in 1 carbon metabolisms
- DNA synthesis and repair
- Formation of RBC and WBC
- AA metabolism
101
Folate coenzyme is important in
Embryogenesis
102
Folate is used in AA metabolism to convert
Histidine to glutamate
| Homocysteine to methionine (with B12)
103
Without B12 THF cannot be regenerated and folate is
Trapped as 5-methyl THF
| Methyl-folate trap
104
Folate is important for
Preventing neural tube defects
105
Women capable of becoming pregnant are recommended to take _______ of folic acid daily
400 mcg
106
The only true government required fortified vitamin
Folate
107
Megaloblastic Macrocytic Anemia is caused by
Folate and B12 Deficiency
108
Megaloblastic Macrocyticc Anemia
- Occurs in 1 month with a low folate diet
- large RBC due to inadequate DNA synthesis
- occurs with B9 and 12 deficiencies
109
Symptoms of Megaloblastic macrocytic anemia
Fatigue, headaches, difficulty concentrating, shortness of breath, and palpitations
110
Neural tube defects caused by folate deficiency
Spina Bifida
| Anencephaly
111
Folate is not toxic with dietary intake but may become toxic with supplemental doses
- masks a b12 deficiency
| - binds with zinc in GI tract, causing a ZN deficiency
112
Sources of folate
- dark leafy veggies
- mushrooms
- liver
- legumes
- fortified cereals (folic acid)
- orange juice
113
Folate instability caused by
Heat and water during cooking
114
Vitamin B12 AKA
Cobalamins
115
Active B12 coenzymes
5-deoxyadenosylcobalamin (5-deoxyadenosyl)
Methylcobalamin (CH3)
116
Methylcobalamin functions in
Folate pathway and homocysteine removal
Heme synthesis
117
Low b12 can cause
Neuropathy
118
Deoxyadenosylcobalamin coenzyme
Threonine and isoleucine metabolism or metabolism of odd-chain fatty acids
119
B12 requirements
Anyone over 50 should consume B12-fortified. Foods or supplements
120
B12 deficiency is caused by _____ ______
Poor absorption
| - intrinsic factor required for absorption
121
Poor absorption of B12 happens as we age because we must have ____; acid suppressing medications decrease _____ and _____ ____
HCL; HCL and B12 absorption
122
Intrinsic factor is secreted from
Parietal cells of stomach
123
Increased difficulty of B12 absorption is caused by
-Saturated receptors which causes all B12 to go to the ileum q
124
Conditions that decrease B12 digestion and absorption
Zollinger Ellison syndrome. (Too much HCL)
Medications (histamine blockers, protein pump inhibitors)
Pancreatic insufficiency
Malabsorptive syndromes (Crohn’s)
125
Folate can get rid of hematologic symptoms of MMA but not neurological symptoms due to demyelination of nerves because of
Decreased DNA synthesis
126
MMA causes
Fatigue, headaches, difficulty concentrating, shortness of breath and PERIPHERAL NEUROPATHY (dif than folate!)
127
Pernicious anemia is a type of
Megaloblastic anemia
128
Pernicious anemia is a _________ condition where antibodies attack _____________ and _________ cells
Autoimmune; gastric parietal and mucosal cells
129
decrease HCL secretion (acholrhydria) causes
Impaired b12 release from food proteins
130
Impaired IF secretion causes
Inability to absorb B12
131
Pernicious anemia is treated with
B12 injections
132
Who is at risk of B12 deficiency?
```
Strict Vegetarians/ Vegans
Elderly (15% deficient, take injections or nasal spray)
Zollinger-Ellison syndrome
Pernicious anemia gastritis
Achlorhydria (decreased HCL)
Malabsorptive conditions
Patients on acid-reducing meds
Pregnant women
```
133
Vegans may not develop B12 ddeficiency for
5-10 years
-tiny requirement and stored up in liver
134
B12 toxicity
No known toxicity
135
Sources of B12
```
Shellfish
Meats
Poultry
Fish
Dairy (5-10% lost through pasteruization)
Fortified Cereals
```
136
B12 is bound to ______ in food
Protein
137
Instability of B12 caused by
Water during cooking
138
Pantothenic Acid
B5
139
Pantothenic acid is part of
Coenzyme A (CoA) and Acyl-carrier protein (ACP)
140
Pantothenic Acid use as CoA
Metabolism of carbs, lipids, and proteins
Synthesis of FA, cholesterol, and heme
141
Acyl Carrier Protein (ACP) contains
Pantothenic acid
142
Sources of pantothenic acid
```
Meats
Poultry
Egg yolk
Legumes
Whole grains
Potatoes
Broccoli
Mushrooms
Avocados
```
143
Pantothenic acid is stable during _____ and _______, but may be lost while ___________________
Cooking and storage; thawing frozen meats
144
Pantothenic acid deficiency causes
Burning feet syndrome
145
Burning feet syndrome
Extremely rare, causes numb toes, burning of feed, depression, fatigue, insomnia, and weakness
146
Biotin coenzyme functions
Bound to carboxylases
| -FA synthesis, gluconeogenesis, metabolism of propionate and leucine
147
Biotin function as a noncoenzyme
Transcription of several enzymes
| Glucokinase, phospoenol pyruvate, carboxykinase
148
Biotin dependent enzymes
Pyruvate carboxylase and Acetyl-CoA carboxylase
149
Role of pyruvate carboxylase
Pyruvate to oxaloacetate
-replenish oxaloacetate for TCA cycle; required for gluconeogenesis.
150
Role of Acetyl-CoA carboxylase
Acetyl-CoA to malonyl-CoA
-committed step of FA synthesis
151
Most common FA made
Palmitic acid
152
Sources of biotin
```
Bacteria in large intestine
Peanuts
Almonds
Soy
Eggs
Dairy
Sweet potatoes
(More in plants than animals)
```
153
Avidin
Protein in raw egg whites that binds biotin and prevents absorption
When eggs are cooked they are denatured and its not a problem
154
Biotin is easily extracted
In water
155
Deficiency of biotin
Rare:
May occur in a person who eats lots of raw egg whites or has biotiidase deficiency
156
Biotinidase Deficiency
Person born with rare genetic donation of inborn error of metabolism of biotin
157
Symptoms of biotin deficiency
Dermatitis, anorexia, depression, alopecia, muscle pain, lethargy, hallucinations
158
Biotin toxicity
No toxicity reported
159
Choline _______ essential
Is not; we synthesize it
160
Lecithin makes up _____ of all phospholipids in the body
50%
161
Phosphatidylcholine AKA
Lecithin
162
Choline functions as lecithin
```
Cell membrane integrity
Lipid transport (lipoproteins)
```
163
Choline functions as choline
Part of acetylcholine
164
Sources of choline
Soy
Eggs
Liver
Meats
165
Choline is easily extracted in
Water
166
Choline deficiency manifests as
Fatty liver disease
| Possibly: cancer, CVD, neural tube defects, dementia
167
Choline toxicity symptoms
Low BP
Fishy body odor
Excessive salivation and sweating
Decreased growth
168
TUL of choline
3.5 g
169
Which B vitamins are involved in pyruvate to acetyl-CoA
Pantothenic acid
Niacin.
Thiamin
170
Which vitamin is NOT involved in ETS?
1. Riboflavin
2. Niacin
3. Coenzyme Q10
4. Vitamin C
4. Vitamin C
171
Niacin synthesis requires
Riboflavin
172
Glossitis with magenta tongue is a clinical indication of which deficiency
Riboflavin
173
NAD is a coenzyme for which class of enzymes?
Dehydrogenase
174
Pantothenic acid is involved in fatty acid synthesis as part of
ACP
175
Biotin deficiency manifests as
Dermatitis
176
Meats are a good source of
Thiamin
177
Diets high in phytochemicals are protective against
CVD, cancer and other chronic diseases
178
Photochemical functions
Antioxidants
Hormonal activity
DNA replication
Antibacterial
179
Lycopne
Red
-tomatoes, pink grapefruit, watermelon
180
Anthocyanins
Red/purple
- berries, grapes, red wine, plums
181
Alpha and beta carotene
Orange
- carrots, mangos, pumpkin, sweet potato
182
Beta-cryptoxathin
Orange/yellow
-cantaloupe, peaches, oranges, papaya, nectaries
183
Lutein, zeaxanthin
Yellow/green
-spinach, avocado, honeydew, turnip greens
184
Sulforaphanes, indoles
Green
Cabbage, broccoli, brussle sprouts, cauliflower
185
Allyl sulphides
White
-onion, garlic, chives, leeks
186
Supplementation needed in pregnancy and lactation
Folate
187
Supplementation for Infants, children, and adolescents
Vitamin D
188
Older adults need supplementation for
B12 and vitamin D
189
Smokers need more
Vitamin C
190
Chronic alcohol intake increases needs of
Thiamin, folate, and B6
191
Vegans need ____supplements
B12
192
Diet lower than _______ Calories require supplements
1200 Cal/d
193
Principles of supplementation
- read the label
- can be harmful in large amounts
- individual needs should be determined
- all nutrients work together
- food is best source of nutrients
194
A Megadose is more than ____ times the RDA of a micronutrient
10
195
Large doses may cause
Deficiency in other micronutrients
196
Deficiencies can occur when people stop overdosing this is called the
Rebound effect
197
At high doses supplements behave more like
Drugs
198
Liver can be damaged from to much__________ vitamins
Fat soluble
199
High dose vitamin C. During pregnancy decreases
Infant birth weight
