9: Vitamins Flashcards
(141 cards)
1
Q
What are vitamins and what do they do?
A
- Vitamins are organic micronutrients
- They facilitate body processes
2
Q
how many vitamins do our bodies require?
A
The body requires 13 vitamins to survive and thrive
3
Q
Are vitamins classified as either water- or fat-soluble vitamins?
A
They are classified as either water- or fat-soluble vitamins according to their behaviour in water
4
Q
what are water-soluble vitamins?
A
hydrophilic and dissolve readily in water
5
Q
what are fat-soluble vitamins?
A
hydrophobic and require a lipoprotein transporter to move around the watery environments of the body
6
Q
what is the consumption frequency of water-soluble vitamins?
A
required more frequently from diet (everyday)
Ex: Vitamin B, C
7
Q
what happens to excess water-soluble vitamins?
A
Excess water-soluble vitamins are excreted in urine (by kidney) and less likely to be toxic
8
Q
what happens to excess fat-soluble vitamins?
A
excess fat-soluble vitamins are stored in adipose tissue, where they can build-up and lead to toxicity
9
Q
what is the consumption frequency of fat-soluble vitamins?
A
Required less frequently from the diet (every few days)
Ex: Vitamin A, D, E, K
10
Q
what are coenzymes?
A
Coenzymes are non-protein factors required for enzyme function
11
Q
T/F: Our daily vitamin needs depend on our age and life stage
A
True,
younger individuals often have lower RDA/AI for various vitamins, while pregnancy and lactation typically increase needs
11
Q
what happens when coenzymes bind to enzymes?
A
they activate the enzymes and allow them to function
12
Q
what are the B vitamins?
A
a group of eight vitamins that act as coenzymes for energy metabolism
13
Q
T/F: The B vitamins provide energy
A
False,
the B vitamins do not provide energy, they support the enzymatic activity that promotes energy metabolism
14
Q
T/F: Many foods naturally contain B vitamins
A
True,
plants and animals naturally contain B vitamins and they are also fortified into foods (grains/cereals)
15
Q
what is Vitamin B1?
A
Thiamine
16
Q
What is the function of Vitamin B1: Thiamine?
A
- required by all body tissues
- plays a role in muscular contraction, nerve conduction and the synthesis of ATP
17
Q
Vitamin B1: Thiamine is part of what coenzyme?
A
Thiamine is part of coenzyme thiamine pyrophosphate (TPP).
- TPP is required for citric acid cycle of cellular respiration and is important for carbohydrate metabolism
18
Q
What are the food sources with Vitamin B1: Thiamine?
A
- abundant in many foods
- nuts, seeds, eggs, milk, poultry, fortified cereals
19
Q
What are the effects of Vitamin B1: Thiamine deficiency?
A
- brain is particularly susceptible to thiamine deficiency ==> can promote neuronal death
20
Q
Vitamin B1: Thiamine deficiency can be associated to what in the developed world?
A
- typically associated with alcoholism ==> poor diet and decreased nutrient intake
- compromises the absorption and storage of thiamine
21
Q
Alcohol-related cases of severe Vitamin B1: Thiamine deficiency can lead to what disease?
A
- Wernicke’s syndrome – a potentially life-threatening disease that compromises central and peripheral nervous systems ==> can progress to Korsakoff syndrome, more severe and permanent neurological symptoms
22
Q
Vitamin B1: Thiamine Deficiency:
What are the symptoms of Wernicke’s syndrome?
A
short-term memory loss, confusion, disorientation and changes in eye movements
23
Q
In the developing world, associated with malnutrition vitamin B1: Thiamine deficiency can lead to what condition?
A
Beriberi - wet or dry
- can be life-threatening
- can lead to Wernicke’s or Korsakoff syndrome
24
Vitamin B1: Thiamine Deficiency:
What are the effects of wet beriberi?
negatively impacts the cardiovascular system and can lead to heart failure
25
Vitamin B1: Thiamine Deficiency: What are the effects of dry beriberi?
negatively impacts the nervous and muscular systems, potentially leading to muscle paralysis
26
Can Vitamin B1 Thiamine become toxic?
Thiamine is well tolerated and excess amounts can be secreted by the kidneys. Dietary toxicity is rare and there is no upper limit
27
What is Vitamin B2?
Riboflavin
28
what does vitamin B2 Riboflavin do?
Riboflavin helps form two important coenzymes: flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)
29
Vitamin B2 Riboflavin:
What does flavin adenine dinucleotide (FAD) do?
FAD picks up electrons during the citric acid cycle to become FADH2. It then transports these electrons to the electron transport chain where they are necessary for ATP production
30
Vitamin B2 Riboflavin: What do the 2 coenzymes FMN and FAD do?
- conversion of the amino acid tryptophan to niacin
- further involved in maintaining appropriate levels of homocysteine, a risk factor for cardiovascular disease (CVD)
31
What are food sources of Vitamin B2 Riboflavin?
Egg yolks, organ meats, fortified breakfast cereals, oats, milk, salmon, tuna, soybeans, dairy products, and almonds are all high in riboflavin
32
T/F: Vitamin B2 Riboflavin is sensitive to light
True, typically packaged in opaque containers to preserve their riboflavin content
33
Vitamin B2 Riboflavin:
What is Riboflavin deficiency called and what are the symptoms?
Ariboflavinosis (rare - more common in vegetarians since riboflavin is in animal products)
Symptoms: skin disorders, swelling in mouth, throat, dry and cracked lips, red eyes and hair loss
34
Is Vitamin B2 Riboflavin Toxicity common?
Rare because body does not absorb more than a certain level and the kidneys excrete excess amounts
- Excess intake from food or supplements have not been observed to promote toxicity
- no upper limit
35
What is Vitamin B3?
Niacin
36
What is the function of Vitamin B3 Niacin?
forms the coenzyme nicotinamide adenine dinucleotide (NAD) ==> AD is a key electron transporter in cellular respiration, picking up electrons to become NADH+H+
37
Vitamin B3 Niacin: Why is NAD so important?
- NAD is critical to many metabolic reactions since more than 400 enzymes require it to function properly
- critical to the metabolism of carbohydrates, lipids and proteins
- NAD involved in reduction/oxidation reactions
38
What are food sources of Vitamin B3 Niacin?
- Animal products (chicken, beef, fish) are high in niacin - Plant products (nuts, legumes, grains) high in niacin, but half the niacin content of animal products
39
What are the special uses of Vitamin B3 Niacin?
- High doses of niacin (>2000 mg) have been shown to reduce triglycerides, lipid transporters VLDL and LDL and increase HDL
- no clear link established with niacin megadoses and decreased risk of heart attacks, strokes, mortality
40
Vitamin B3 Niacin deficiency can cause what? and what are the symptoms?
Causes Pellagra
- 4Ds of pellagra: dermatitis, diarrhea, dementia, death
41
Can Vitamin B3: Niacin Toxicity occur?
- rare from food
- Doses of 30 mg or more can cause niacin flush
- Medically prescribed doses of more than 1,000 mg/day can lead to nausea and vomiting, low blood pressure, fatigue, insulin resistance
42
Vitamin B3 Niacin:
What is Niacin Flush?
flushing, or reddening, of the skin accompanied by burning and itching sensations
43
What is the function of Vitamin B5 Pantothenic Acid?
Pantothenic acid helps form coenzyme A ==> essential for energy metabolism
44
What is Vitamin B5?
Pantothenic Acid
45
Vitamin B5 Pantothenic Acid: What is the function of Coenzyme A?
Coenzyme A is required for lipid, carbohydrate and certain amino acid metabolites to enter the citric acid cycle as acetyl CoA ==> essential for energy metabolism
46
What are food sources of Vitamin B5 Pantothenic Acid?
Pantothen is Greek for everywhere
- available in a wide variety of both animal and plant products, fortified cereals, beef, chicken, grains, vegetables
47
Is Vitamin B5 Pantothenic Acid Deficiency common?
Due to its abundance in a variety of foods, pantothenic acid deficiency is rare
48
What are symptoms of Vitamin B5 Pantothenic Acid Deficiency?
numbness in the hands and feet, headache, tiredness, disturbed sleep and gastrointestinal issues
49
What is Vitamin B6 the generic name of?
Vitamin B6 is the generic name for six different vitamers
50
Vitamin B6:
What are Vitamers?
- different forms of the same vitamin that have a common function
51
Vitamin B6:
What are the functions of Vitamers?
- act as coenzymes in the catalyzation of more than 100 enzymatic reactions, including metabolism of carbs, lipids and amino acids
- help form neurotransmitters (serotonin, norepinephrine)
51
Vitamin B6 helps lower what?
vitamin B6 helps lower homocysteine levels by converting it to cysteine
- Elevated levels of homocysteine are a risk factor for CVD
52
Vitamin B6, B9 and B12 are involved in what?
Vitamin B6, B9 and B12 are involved in regulating homocysteine levels
53
What are the special uses of Vitamin B6?
- improving cognitive function
- reducing CVD risk, premenstrual syndrome (PMS), vomiting and nausea in pregnancy
==> however, no firm link has been established
54
What are food sources of Vitamin B6?
Plant: CHICKPEAS,
Animal: beef liver, tuna, salmon, chicken
Food: fortified cereals, grains, potatoes, bananas, squash, rice
Supplement: Pyridoxine
55
Is Vitamin B6 deficiency common?
Vitamin B6 deficiency is rare in isolation and is often found in combination with other B vitamin deficiencies
56
Vitamin B6 deficiency can lead to what? And what are the symptoms?
Microcytic Anemia: red blood cells are small and do not properly transport oxygen.
Symptoms: fatigue, lethargy, dry and cracked lips, and a swollen tongue
57
What can occur due to prolonged supplementation of <1000 mg/day of pyridoxine, the supplement form of
Vitamin B6?
loss of control over body movements
58
What is Vitamin B7?
Biotin
58
Vitamin B7 Biotin is the generic name for what? and what are the functions?
Biotin is the generic name for five vitamers that function as coenzymes
- involved in cell signalling and DNA structure and function
59
What are the special uses of Vitamin B7 Biotin?
improve hair, nail, skin health
==> however, clear benefit has not been scientifically established
60
What are food sources of Vitamin B7 Biotin?
- abundant in many foods
- beef liver offers 100% of RFA
- chicken, tuna, pork, sunflower seeds, sweet potatoes, almonds, spinach, broccoli
61
What factors can cause Vitamin B7 Biotin deficiency?
- deficiency is rare
- genetic disorder called biotinidase deficiency
- can progress to seizures, depression and decreased muscle tone and strength
62
Vitamin B9 can exist in what forms?
Folate = basic form (food)
Folic Acid = acidic forms (supplements)
63
What are the functions of Vitamin B9 Folate/Folic Acid?
coenzymes in the synthesis of DNA/RNA, metabolism of amino acids, and involved in conversion of homocysteine to methionine
64
What are food sources of Vitamin B9 Folate?
Beef Liver! Spinach, legumes, asparagus, Brussels sprouts, avocados
65
Vitamin B9 Folate deficiency during pregnancy can lead to what?
offspring can develop neural tube defects
- birth defects like spina bifida (leg weakness, scoliosis, bladder, bowel issues) and anencephal (born missing major parts of their brain)
66
Vitamin B9 Folate deficiency can lead to what disorder?
Megaloblastic Anemia: red blood cells are immature, large, misshapen and unable to properly carry oxygen (tiredness, weakness, heart irregularities)
67
T/F: Folate deficiency has potential link with autisim
True, but firm link has not been established
68
Vitamin B9 Folate toxicity can promote what symptoms?
rare, but may promote nausea, bloating, decreased appetite, difficulty sleeping
69
T/F: Vitamin B9 Folate can mask a Vitamin B12 deficiency
True,
if folate intake is high, it can mask Vitamin B12 deficiency since it can prevent megaloblastic anemia
70
What is Vitamin B12?
Cobalamin
- various vitamers collectively known as cobalamins
71
What is the function of Vitamin B12 Cobalamin?
- required for DNA synthesis, formation of mature red blood cells, brain function
- acts as a coenzyme in the conversion of homocysteine to methionine
72
What are the special uses of Vitamin B12 Cobalamin?
decrease risk of dementia, evidence is currently lacking to support supplementation
73
what is the absorption process of Vitamin B12 Cobalamin?
- relies on stomach secretions
1) stomach releases HCL acid to free B12 from food
2) stomach also releases intrinsic factor (IF) needed later for B12 absorption
3) in small intestine, B12 binds to IF, allowing B12 to be absorbed
74
Vitamin B12 Cobalamin Absorption: What is Atrophic Gastritis?
autoimmune disorder that breakdown stomach’s lining, restricts intrinsic factor secretion ==> increasing risk for vitamin B12 deficiency
- common in older adults
75
What are food sources of Vitamin B12 Cobalamin?
- found only in animal products with exception of nutritional yeast
- Shellfish, fish, beef liver
- Vitamin B12 supplementation
76
Vitamin B12 Cobalamin deficiency can lead to what?
Megaloblastic anemia (large misshapen RBC, large highly segmented WBC)
77
what are symptoms of Vitamin B12 Cobalamin deficiency?
impacts nervous system, promote balance issues, depression, poor memory, confusion
78
What is Vitamin C?
Ascorbic Acid
79
What is the function of Vitamin C Ascorbic Acid?
- critical for collagen formation
- protein metabolism
- antioxidant function
- increase absorption of iron, reducing risk for iron-deficiency anemia
80
Vitamin C Ascorbic Acid:
What are antioxidants?
substances that help reduce activity of free radicals (reactive molecules with an unpaired electron)
81
How is Vitamin C an antioxidant?
Antioxidants stop oxidation by donating their extra electrons to free radicals, neutralizing them so they cannot cause damage
82
What are special uses of Vitamin C Ascorbic Acid?
Immune system effects: supports function of immune system, lower risk of cold before occuring
Chronic Disease Prevention: may reduce cancer, CVD risk
==> supplementation has not been shown to reduce risk
83
Vitamin C Ascorbic Acid deficiency can lead to what?
Scurvy ==> bleeding gums, fatigue, poor collagen formation
83
What are food sources of Vitamin C Ascorbic Acid?
- synthesized by animals
- fruits, vegetables
84
What can occur from Vitamin C Ascorbic Acid toxicity?
over 2000 mg/d can promote gastrointestinal effects (diarrhea, nausea, abdominal cramps)
85
Indigenous Lens Cure for Scurvy: What is the Tree of Life
Bark of Annedda tree and concoction of boiled winter leaves help cure scurvy as it was high in vitamin C
86
What are the 4 fat-soluble vitamins?
Vitamins A, D, E, K
87
What lipid carriers are required for fat-soluble vitamins?
lipid carries micelles and lipoproteins
88
The group of Vitamin A Vitamers are called what?
Retinoids
89
What are the two forms we consume Vitamin A?
Provitamin A and Preformed Vitamin A
90
What is Provitamin A?
- found in plants
- vitamers are known as Carotenoids (not in active form) must be converted into retinols
91
Where is Preformed Vitamin A found?
- found in almost-active forms (retinol and retinal ester) ==> found in animal products
92
How do Preformed Vitamin A retinoids become fully active?
body must convert retinols into retinal and retinoic acid ==> active form of Vitamin A
93
How does Vitamin A play a role in the Visual Pathway?
1) Rhodopsin is visual pigment in eye retina (composed of retinal bound to opsin)
2) rhodopsin stimulated when visual stimuli projected on retina
3) cause retinal to change shape => nerve message sent to brain about what was seen
4) retinal and opsin break apart
5) some retinal lost in process, replenished with retinal from dietary vitamin A intake
6) retinal and opsin come together again to repeat process
94
What are the functions of Vitamin A?
Gene Expression: turn certain genes on/off
Immune Function: formation of infection-fighting T-cells
Carotenoid Form (plants) : anitoxidant
95
What are special uses of Vitamin A?
promotes skin health by switching on genes that cause immature skin cells to become mature and healthy
96
What are food sources of Vitamin A?
Preformed vitamin A found in animal products
Provitamin A found in plant products
97
T/F: Vitamin A improves our ability to see at night
False,
while Vitamin A can help prevent night blindness, it does not improve night vision
98
Vitamin A deficiency can lead to what?
Xerophthalmia = abnormal dryness of eye affecting body’s ability to form tears
==> If untreated, can lead to breaks in cornea eye, potentially blindness
99
Vitamin A Toxicity: high intakes of preformed vitamin A from animal products can lead to what serious side effects?
elevated pressure around the brain, dizziness, nausea, headaches and can be fatal
==> overconsuming supplements, or polar bear liver
100
What is the function of Vitamin D?
- maintaining calcium homeostasis
- increase calcium, magnesium, phosphorus absorption
- cellular growth, immune function, reduction of inflammation
100
Vitamin D is the generic name for what?
generic name for a group of compounds, Vitamin D3 (Cholecalciferol), Vitamin D2 (Ergocalciferol)
101
What are special uses of Vitamin D?
studied for its role in cancer prevention, but supplementation has not been established to lower risk
102
What are food sources of Vitamin D?
- not widely available in foods
- Fatty fish (salmon, tuna, mackerel, fish oils)
- orange juice, milk => fortified Vitamin D
- sun exposure
103
How does activation of Vitamin D occur from the sun?
1) UVB light hits the skin, promote synthesis of Vitamin D3 from precursors
2) liver modifies Vitamin D3 into form of Vitamin D that circulates through blood
3) kidneys must convert circulating version into its active form
104
Is Vitamin D deficiency common?
common due to inadequate dietary consumption - limited sun exposure
105
what factors can increase Vitamin D deficiency?
older adults, individuals with black skin, obesity, breastfed infants, people who have undergone gastric surgery
106
Vitamin D deficiency in children can promote what?
Rickets = lack of bone mineral density that leads to soft bones
==> bowlegs are a characteristic
107
Vitamin D deficiency in adults can lead to what?
Osteomalacia – softening of bones due to decreases in bone mineralization
- can progress to osteoporosis = weakened, less hardened bone tissue, more likely to break
108
Vitamin D Toxicity can promote what?
rare but typically over-supplementation
- anorexia, weight loss, increased urination, irregular heart rhythms
- increase blood calcium, harden blood vessels, eyes, impact kidneys/heart
108
Vitamin E is a generic term for how many vitamers?
generic term for eight vitamers (alpha tocopherol)
108
What is the function of Vitamin E?
antioxidant role (free radicals by donating electrons and neutralizing them)
- immune function, cell signalling, gene expression
109
What are food sources of Vitamin E?
- oily germ of cereal grains
- vegetable oils, fatty shellfish, fatty plants (nuts, seeds, fortified cereal, nut butter)
109
What are special uses of Vitamin E?
studied for potential to decrease cancer, CVD, Alzheimer's risk but supplementation has not been shown to decrease risk
110
Vitamin E deficiency is typically due to what factor and what are the symptoms?
compromised fat absorption, individuals with gastric surgery, Chron’s disease, cystic fibrosis Symptoms: peripheral neuropathy, movement difficulties, muscle disorders, impaired immune response
111
Vitamin E toxicity is due to what?
Over-supplementation => increasing mortality risk
- lung illness in vape (high levels of Vitamin E in blood of vapers (difficult breathing, chest pain, fatigue, vomiting))
112
Vitamin K was named based on what?
named based on Danish word coagulation (blood clotting)
113
Synthesis of protein Prothrombin is dependent on what?
dependent on a vitamin K coenzyme
- Prothrombin is needed for the pathway that leads to formation of sticky fibrin fibres to help RBC clump together
114
What are food sources of Vitamin K?
leafy green vegetables, spinach, broccoli, oils, nuts, liver, ham, cheese, milk
- healthy gut microbiota contributes to vitamin K bioavailability, certain organisms synthesize different forms of vitamin K
115
Why is Vitamin K deficiency a high risk for newborns?
Newborns are at high risk for vitamin K deficiency since it is poorly delivered via the placenta
- lead to excessive bleeding, hemorrhaging
116
Vitamin K: What is Warfarin?
drug, anticoagulant blood thinner that blocks Vitamin K dependent coagulation pathway
- prescribed for those high risk for heart attacks and strokes
117
Vitamin Infused Beverages
- make vague promises based on vitamin provision
- regulated as natural health products, do not have nutrient facts box
- contain water soluble vitamins, less likely to be deficient in diet
- may have a lot of added sugars
118
Each gram of vitamins provides ______kcal of energy
0
119
The ________ is/are particularly susceptible to thiamine deficiency
brain
120
Niacin deficiency can lead to:
Pellagra
121
Excessive intake of ___________ may lead to a flushing of the skin
Niacin
122
The fortification of grain with _____________ has led to a reduction in the incidence of neural tube defects
Vitamin B9 Folate/Folic Acid
123
__________, which is secreted by the stomach, is needed for the absorption of vitamin B12
Intrinsic Factor
124
T/F: The first known cure for scurvy was discovered by Dr. James Lind who ran experiments in British sailors
False,
The first known cure is attributed to Iroquois who lived in present day Quebec city and who cured Jacques Cartier's crew of the condition
125
Which of the following forms of vitamin A is the most active?
Provitamin A, Preformed vitamin A, Retinal, Retinol, Carotenoids
Retinal
126
The active form of vitamin A is found in the eye's retina bound to a a substance called opsin. The resulting structure, _____________, is responsible for the perception of visual stimuli
Rhodopsin
127
T/F: Eating carrots (high in vitamin A) improves out ability to see at night
False, rumour started by the British Air Force during WW2
128
Vitamin D's main role is in promoting _____________ homeostasis
calcium
129
T/F: Vitamin D supplementation reduces risk of colon cancer
False
130
Vitamin D deficiency in childhood can lead to ___________, resulting in misshapen bones
Rickets
131
T/F: Vitamin D toxicity can lead to the hardening of the kidneys and heart
True
132
T/F: Vitamin E supplements have been shown to reduce mortality risk
False
133
Breast milk is low in ___________, thus a shot of this vitamin is typically administered to newborns
Vitamin K
