Module 8 - Water-Soluble Vitamins Flashcards
1
Q
When and by who, was the term vitamins formed?
A
1912, by Casimir Funk, made the term “vitamine”, “vita” = necessary for life, “amine” = nitrogen containing substance
2
Q
Why was the term “vitamine” modified to “vitamin”?
A
Not all are amines
3
Q
What does the term vitamin mean?
A
complex organic compound that regulates metabolic processes
4
Q
What do vitamins promote?
A
normal functioning, growth, and maintenance
5
Q
What are the similarites and differences between vitamins and macronutrients?
A
Similarities: Organic (carbon containing)
Differences: daily needs of vitamins are small, individual units instead of long chains, not a source of energy but play crucial role in reactions that extract energy from macros (coenzymes!)
6
Q
What is a coenzyme?
A
coenzyme attach to inactive enzyme allowing enzyme to become active
7
Q
What are sources of vitamins?
A
plants, animals, fungi, bacteria and supplements
8
Q
Is it necessary to consume 100% of every vitamin every day?
A
No
9
Q
What place in the body can produce vitamins?
A
Gut microbiota can produce biotin and vitamin K that can be absorbed to an extent
10
Q
What does “bioavailability of vitamins” refer to?
A
Amount actually available for use by the body
11
Q
What factors affect bioavailability of vitamins?
A
Life stage and nutrient status
Changes to normal GI transit time
Health conditions
Food processing and preparation
Sources of vitamin
12
Q
Where are vitamins primarily absorbed?
A
Small intestine
13
Q
Are vitamins fully absorbed?
A
No, but small intestine can increase absorption if necessary by body
14
Q
What facilitates absorption of vitamins?
A
Fat digestion (Bile)
15
Q
How can you enhance vitamin absoprtion?
A
By adding small amounts of fat (adding butter to broccoli)
16
Q
What are the Water-Soluble Vitamins and Fat Soluble Vitamins?
A
Water-soluble: B vitamins and vitamin C
Fat-soluble: vitamin A, D, E, K (ADEK)
17
Q
The difference in solubility of fat soluble and water soluble vitamins affects…
A
the bodies absorption, transport and storage of the vitamin
18
Q
How are fat-soluble vitamins absorbed?
A
intestinal cells absorb fat-soluble vitamins (along with fat), packaged into lipoproteins, enter lymph system, reach liver where they are stored/repackaged for delivery to other tissues
19
Q
Where do excess fat-soluble vitamins go?
A
Accumulate in liver and fatty tissues (reserves can last for weeks or months)
20
Q
How are water-soluble vitamins absorbed?
A
Intestinal cells absorb water-soluble vitamins directly into the bloodstream
21
Q
What is the difference in storage quantity between fat soluble and water soluble vitamins?
A
Fat soluble vitamins are stored in large amounts and reserves can last for weeks or months Water-soluble vitamins are not stored in large amounts, needed regularly from diet
22
Q
What happens to excess water-soluble vitamins?
A
kidneys can excrete in urine
23
Q
Steps of Vitamin Absorption
A
- Chewing breaks food apart, helping to release vitamins
- Digestion of food in stomach releases vitamins, some niacin absorbed
- Gallbladder releases bile, helps absorb fat-soluble vitamins
- Pancreas secretes digestive enzymes that aid in release of vitamins from food
- in small intestine, fat soluble vitamins are incorporated into micelles and absorbed into mucosal cells, then packaged into chylomicrons, which enter the lymph before passing into blood and eventually liver
- Water soluble vitamins are absorbed from the small intestine directly into blood
- In large intestine, bacteria synthesize small amount of vitamins, some of which are absorbed
24
Q
Explain role of mouth in vitamin absorption
A
Chewing breaks food apart, helping to release vitamins
25
Explain role of stomach in vitamin absorption
Digestion of food in stomach releases vitamins, some niacin absorbed
26
Explain the role of Gallbladder in vitamin absorption
Gallbladder releases bile, which emulsifies fat and helps absorb fat soluble vitamins
27
Explain the role of the Pancreas in vitamin absorption
Pancreas secretes digestive enzymes that aid in release of vitamins from food
28
Explain fat soluble vitamin absorption in the small intestine
fat soluble vitamins are incorporated into micelles and absorbed into mucosal cells by simple diffusion, then packaged into chylomicrons, which enter the lymph before passing into blood and eventually liver
29
Explain water-soluble vitamin absorption in the small intestine
Water-soluble vitamins are absorbed from the small intestine directly into the blood
30
Explain the role of large intestine in vitamin absorption
Gut microbiota synthesizes small amounts of vitamins, some which are absorbed
31
What can lead to reduced vitamin absorption and lead to deficiencies?
Diseases that affect GI tract (eg. cystic fibrosis - unable to digest fat properly; often develop deficiencies of fat-soluble vitamins)
32
How can vitamin absorption be increased through medicine?
Large oral doses or injections enable small amounts of vitamins to be absorbed
33
What is enrichment of vitamins?
addition of vitamins that were taken our during refinement; helps protect from deficiencies of thiamin, riboflavin, niacin, folate, iron
34
What is NOT added back in enrichment process?
Vitamin E, B6, Magnesium, fiber, other micronutrients that were present in unrefined grain
35
What is fortification of vitamins?
addition of vitamins that weren’t originally there; some concerns over excessive amounts of some vitamins while reducing intake of others
36
What is Vitamin Toxicity?
When cells are saturated with a vitamin, continuing to take vitamin can produce toxicity disorder (exposure to excess micronutrient or its by-products can damage cells)
37
What can occur due to vitamin toxicity?
Liver damage when intake level of some vitamins is toxic
38
Why does Vitamin Deficiency occur?
inadequate diets or conditions that increase body’s requirement for vitamins (e.g., reduced intestinal absorption)
39
What types of vitamins are usually consumed less than recommended amounts?
Fat-soluble vitamins (A,D,E,K)
40
What populations are at risk for vitamin deficiencies?
alcoholism, older adults, hospitalized patients, people consuming low fat, people with intestinal conditions that affect absorption
41
How many B vitamins are there?
8
42
Name all 8 B-vitamins
Thiamin (B1)
Riboflavin (B2)
Niacin (B3)
Pantothenic Acid (B5)
Biotin (B7)
Vitamin B6
Folate (B9)
Vitamin B12
43
What is Vitamin B1 also called
Thiamin
44
What are the functions of Vitamin B1?
- Part of coenzyme TPP (needed to make acetyl CoA, necessary for breakdown of CHO)
- Needed for synthesis of neurotransmitters
45
Thiamin found in __ amounts in __ foods
small
many
46
Deficiency of Thiamin can lead to Beriberi, describe it
body systems begin deteriorating; deficient glucose metabolism
47
What are signs of Beriberi (caused by Thiamin - Vitamin B1 deficiency)
digestive: diarrhea
muscle: wasting and pain
nerve: disrupts coordination, "pins and needles"
48
Deficiency of Thiamin can lead to Wernicke-Korsakoff Syndrome, describe it
Degenerative brain disorder associated with thiamin deficiency, primarily caused by alcohol-induced malnutrition b/c alcohol reduces thiamin absorption and increases its excretion
49
Signs of Wernicke-Korsakoff Syndrome (caused by Thiamin - Vitamin B1 deficiency)
abnormal eye movements, staggering gait, distorted thought process
50
How can you resolve Wernicke-Korsakoff Syndrome?
eliminate alcohol and obtain thiamin injections, without prompt treatment, permanent disability or death
51
What are food sources of Thiamin (Vitamin B1)
grain products, pork and ham
52
What is Vitamin B2 also called?
Riboflavin
53
What are the functions of Riboflavin (Vitamin B2)?
- forms active coenzyme FAD (needed in glycolysis, CAC, ETC)
- important for breakdown of fatty acids
- works as coenzyme during deamination of some AA
- Involved directly or indirectly in converting folate, niacin, vitamin B6 and vitamin K into their active forms
54
What is Riboflavin (Vitamin B2) sensitive to?
Light, it can destroy it
55
What is the best source of Riboflavin (Vitamin B2)
Milk
56
How can you protect Riboflavin (Vitamin B2) from light?
Store in opaque containers
57
What two vitamins are sensitive to lighting?
B2 and A
58
What is Riboflavin (Vitamin B2) deficiency called?
Ariboflavinosis
59
What are signs/symptoms of Ariboflavinosis (Vitamin B2 deficiency)?
- Fatigue
- Chapped lips/corners of mouth
- Dermatitis
- Glossitis (swollen tongue)
60
What is Vitamin B3 also called?
Niacin
61
What is the function of Niacin (Vitamin B3)?
- Forms active coenzymes NAD, NADP (involved in glycolysis, CAC, ETC)
- needed to synthesize fatty acids and cholesterol
62
What makes Niacin (Vitamin B3) unique among other B vitamins?
body can synthesize it from AA tryptophan (but need other nutrients as well)
63
How much of Niacin intake comes from AA Tryptophan?
half of niacin intake is from tryptophan
64
How much tryptophan yields 1 mg of Niacin?
60 mg, 1 NE (Niacin Equivalent) = 60 mg of tryptophan
65
What is the process in determining dietary Niacin (B3)?
determine amount of protein consumed (g) above RDA (0.8g/kg)>excess daily protein/100=grams of tryptophan (as approx. 1% tryptophan in most sources of dietary protein)>multiply by 1000 for mg>add together amount of food niacin and niacin available from tryptophan to get estimate of dietary niacin
66
What are best sources of Niacin (Vitamin B3)?
Chicken and meats, bread
67
What is Niacin (Vitamin B3) deficiency called?
Pellagra
68
What are signs/symptoms of Pellagra (Niacin-B3 deficiency)?
poor appetite, weight loss, weakness, 4 D's (dermatitis, diarrhea, dementia, death)
69
What is the UL for Niacin (Vitamin B3)?
35 mg/day, usually from fortified foods or supplements (Megadoses of niacin may be prescribed to reduce LDLc and increase HDLc)
70
What are side effects of Niacin (B3) toxicity?
flushing of skin, tingling sensation in hands/feet, GI upset, nausea / vomiting, liver damage, high blood sugar levels, blurred vision
71
What is Vitamin B5 also called?
Pantothenic Acid
72
What is the function of Pantothenic Acid (Vitamin B5)?
Component of CoA (required to make Acetyl CoA), important for breakdown of CHO, fatty acids, AA
73
How can Pantothenic Acid (Vitamin B5) be easily damaged?
- freezing, canning
- processing and refining grains
- cooking
74
What are the best sources of Pantothenic Acid (Vitamin B5)?
Sunflower Seeds, lentils, milk, chicken
75
Is Pantothenic Acid (Vitamin B5) deficiency common?
Virtually nonexistent in general population because wide distribution of B5 in foods
76
In research settings, what has been found as symptoms of Pantothenic Acid (B5) deficiency?
Irritability, fatigue, cramps, tingling
77
What is Vitamin B7 also called?
Biotin
78
What are the functions of Biotin (Vitamin B7)?
Biotin coenzyme participates in chemical reaction that adds CO2 to other compounds, promotes synthesis for glucose and fatty acids, breakdown of some amino acids
79
What is 1 very important function of Biotin (B7)?
Regenerating oxaloacetate in CAC cycle
80
What are best sources of Biotin (Vitamin B7)?
Chicken Liver, Beef Liver, Egg, Peanuts
81
What population is Biotin (B7) deficiency common?
people consuming raw egg whites or receiving total parenteral nutrition (through vein) without biotin
82
What are symptoms of Biotin (Vitamin B7) deficiency?
- dermatitis
- CNS abnormalities (depression, lethargy)
- infants experience developmental delays
83
What do Vitamin B6, Folate (B9), Vitamin B12 work together to acheive?
control Homocysteine levels, support RBC synthesis
84
What is homocysteine?
amino acid which can be turned into methionine and cysteine
85
Why are elevated homocysteine levels dangerous?
increased risk of dementia, heart disease and stroke
86
What is the coenzyme formed from Vitamin B6?
Pyridoxal Phosphate (PLP)
87
What are the functions of Pyridoxal Phosphate (PLP) formed from Vitamin B6?
- facilitates transamination reactions that form nonessential amino acids; also needed for conversion of tryptophan to niacin
- converts potentially toxic amino acid homocysteine to cysteine
- participates in production of heme (iron-containing portion of hemoglobin)
88
What is hemoglobin
Protein in RBC that transports O2
89
Deficiency of Vitamin B6 results in...
1. all amino acids becoming essential (B6 needed for transamination)
2. Anemia (deficiency of hemoglobin synthesis)
3. Heart Disease (build up of homocysteine)
90
Toxic levels of B6 (usually from fortified food or supplements) result in...
sensory nerve damage (walking difficulties, numbness)
91
Are the effects of B6 toxicity reversible?
YES, when megadoses or supplements are stopped
92
Where does the name Folate (group of related compounds that includes folic acid) come from?
"foliage" - leafy greens are a great source of folate
93
What has higher bioavailability: folate or folic acid?
Folic acid (form found in fortified food and supplements) - Folate has many glutamate molecules, and the body can only absorb one glutamate at a time, so each glutamate molecule removed by enzymes in brush border of small intestine
94
What are the 3 functions of Folate (B9)?
1. essential for healthy embyotic development
2. THF can transfer CH3 group to vitamin B12, which transfers CH3 to homocysteine forming methionine (B12 needed for B9 to be used)
3. THF needed to make DNA as cells divide
95
Folate is converted to...
tetrahydrogolate (THF), participates in many chemical reactions involved in DNA synthesis and AA metabolism
96
Best source of B9 Folate
Lentils, fruits and veg
97
When pregnant women do not consume enough Folate (B9)...
Neural tube defects occur - can result in Anencephaly (brain malformed/missing) or Spina bifida (spine does not form properly)
98
In what populations are risk of deficiency of Folate (B9) increased
Pregnant women, infants, children (periods of increased growth)
99
Deficiency of Folate (B9) can result in what type of anemia?
Megaloblastic Anemia - folate needed for division of RBC - immature and larger RBC formed that are inefficient O2 carriers
100
Deficiency of Folate (B9) results in...
heart disease. Build up of homocysteine as THF is needed to turn homocysteine into methionine by transfer of CH3 - results in heart disease
101
How does build up of homocysteine result in heart disease?
build up of homocysteine> more prone to endothelial cell injury >inflammation > atherosclerosis
102
Toxic levels of Folate (B9) result in...
hives, respiratory distress, masks symptoms of B12 deficiency (similar symptoms however B12 deficiency results in nerve damage)
103
What are the functions of vitamin B12?
1. essential for maintaining myelin sheath
2. support rbc synthesis
3. needed for homocysteine mtabolism
104
Why is B12 important for folate (B9) functions?
B12 is essential for conversion of methyl folate to its active form, without B12, folate (B9) is inactive
105
What population needs to be concerned with B12 intake?
vegans (plant foods are not sources of B12)
106
In digestion, B!2 is bound to..
animal proteins that prevent absorption until HCl separates them
107
Where is B12 stored?
liver (enough to last 5-10 years)
108
Most cases of B12 deficiency result from...
problems that interfere with intestinal absorption (limited HCl production due to age, alcoholism, gastritis and medications)
109
Lack of intrinsic factor prevents absorption of...
Vitamin B12
110
What illness can cause stomach to stop making Intrinsic Factor and thus prevent B12 absorption?
Autoimmune disorder
111
How are people with autoimmune disorder treated to increase B12 when lack of IF?
monthly B12 injections or nasal gel
112
Deficiency of Vitamin B12 results in...
1. degeneration of myelin sheath that coats nerves
2. Pernicious (deadly) anemia
- low B12 causes low RBC production
3. Heart disease - B12 helps break down homocysteine by converting it to methionine
113
Folate, Vitamin B12, and vitamin B6 work in concert to ___ blood levels of ___. Each vitamin forms a ___ that helps convert homocysteine to other AA (methionine and cysteine). Low intakes B6, Folate and B12 can increase homocysteine levels, and high levels may be a marker for ___.
lower
homocysteine
coenzyme
heart disease
114
Folate, Vitamin B12, and vitamin B6 work together to ensure proper O2 carrying capacity of ___ (either through production of ___ rbc [folate & vitamin B12] or through normal ___ synthesis [vitamin B6]).
red blood cells
normal
hemoglobin
115
Biotin is essential for what processes?
gluconeogenesis and for regenerating oxaloacetate in CAC
116
Five B-complex vitamins thiamin, riboflavin, niacin, pantothenic acid, and biotin all play a role in ____
metabolizing CHO, PRO, FAT
117
Thiamin (TPP), riboflavin (FAD), niacin (NAD), and pantothenic acid (CoA) … all essential for ___
CAC
118
What is the general role of Vitamin C?
it is an antioxidant, works with fat soluble vitamin E
119
Other name for vitamin C
ascorbic acid
120
Unlike the 8 B vitamins, vitamin C does not act primarily as a ___
coenzyme
121
2 main functions of vitamin c
1. antioxidant activity (helps protect cells from oxidative damage)
2. collagen synthesis
122
Explain how vitamin C functions as an antioxidant
helps protect cells from oxidative damage caused by free radicals (reactive oxygen molecules - ROS)
123
What do antioxidants do?
destroy ROS (reactive oxygen molecule - odd number of electrons) before they can do excessive cellular damage
ANTI OXIDANT
124
What two vitamins function as antioxidants?
C and E
125
How does vitamin C neutralizes ROS?
donates electrons to ROS to create even number of electrons or donates electrons to other antioxidant
126
Neutralized free radicals can no longer...
damage molecules like DNA or phospholipids
127
Vitamin C is unstable in presence of...
light, O2, heat
128
Deficiency of vitamin C results in...
scurvy
129
What occurs in scurvy (vitamin c deficiency)
connective tissues break down bc body can not synthesize collagen (gums, joints begin to bleed, loose teeth, bone pain, fractures)
130
Vitamin c toxicity is linked to
GI discomfort, cramps, diarrhea, antioxidant role leads to pro oxidant - increased iron absorption leads to generation of free radicals
131
Fresh produce retain natural vitamin content better when..
stored at temp near freezing, high humidity, away from air
132
