Chapter 8 - Vitamins Flashcards
1
Q
Water Soluble Vitamins
A
2
Q
What is the RDA of B1 - Thiamine
A
1.2 mg for men
1.1 mg for women
3
Q
Functions of Thiamine
A
- Plays a role in muscle contraction, nerve conduction, and the synthesis of ATP
- Contributes to thiamine pyrophosphate (TPP), a coenzyme required for cellular reactions and the citric acid cycle
4
Q
Sources of thiamine
A
nuts, seeds, eggs, milk, poultry and fortified cereal
5
Q
Thiamine Deficiency
A
- The brain is particularly susceptible and can lead to neuronal death
- Alcoholism can lead to thiamine deficiency and in severe cases cause wernickes syndrome - associated with short-term memory loss, confusion, disorientation, and changes in eye movement. If not treated can lead to ferment damage also known as korsakoffs syndrome
- Wet Beriberi which negatively impacts the cardiovascular system and can lead to heart failure
- Dry Beriberi which impacts the nervous and muscular systems
6
Q
Thiamine toxicity
A
N/a no upper limit, thiamine is well tolerated by the kidneys
7
Q
What is the RDA of B2 - Riboflavin
A
1.3 mg for men
1.1 mg for women
8
Q
Riboflavin function
A
- Help form flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) which picks up electrons during the citric acid cycle
- converts tryptophan to niacin
- maintains levels of homocysteine (risk factor for CVD)
9
Q
Sources of riboflavin
A
Egg yolk, oregano meat, fortified cereal, oats, milk, salmon, tuna, soybeans, and almonds
10
Q
Riboflavin deficiency
A
- ariboflavinosis: skin disorders, swelling in the mouth and throat, dry and cracked lips, red eyes, and hair loss
- thyroid hormon deficiency and lack of meat may cause this
11
Q
Riboflavin toxicity
A
N/a no upper limit
12
Q
What is the RDA and UL of B3 - Niacin
A
16mg for men
14 mg for women
UL: 35mg
13
Q
Niacin functions
A
- forms the coenzyme nicotinamide adenine dinucleotide (NAD) which is a key electron transporter in cellular respiration
- NAD is required by over 400 enzymes so niacin is involved in many different reactions in the body
14
Q
Sources of Niacin
A
animal products such as chicken, beef, fish and plant products such as nuts, legumes, and grains
15
Q
Niacin deficiency
A
- Pellagra: dermatitis, diarrhea and dementia and can also lead to death
16
Q
Niacin toxicity
A
_ usually seems in people taking high levels for management of blood lipids and CVD
- Niacin flush: flushing or reddening of the skin accompanied by burning or itching
- Can also lead to nausea and vomiting
17
Q
Niacin special uses
A
Has been prescribed by doctors for improving blood lipids associated with CVD - reduced triglycerides, VLDL and LDL
18
Q
What is the AI of B5 - Pantothenic acid
A
5mg
19
Q
Pantothenic acid functions
A
helps form coenzyme A - required for citric acid cycle
20
Q
Sources of pantothenic acid
A
fortified cereals, beef, chicken, grains and vegetables but is widely found
21
Q
Pantothenic deficiency
A
Rare
- if present is often associated with malnutrition
- May lead to numbness in hands and feet, headache, tiredness, disturbed sleep, and GI issues
22
Q
Pantothenic toxicity
A
megadoses have been associated with diarrhea and digestive tract distress but there is no upper limit and toxicity is rare
23
Q
what is the RDA and UL of B6
A
RDA 1.3 mg
UL 100 mg
24
Q
B6 functions
A
- involved in more than 100 enzymatic reactions including the metabolism of carbohydrates, lipids, and amino acids
- help to form neurotransmitters such as serotonin and norepinephrine which supports cognitive functions
-helps lower homocysteine levels by converting it to cysteine
25
Sources of B6
chickpeas, beef liver, tuna, salmon, chicken, fortified cereals and grains, potatoes, bananas, squash, rice
26
B6 deficiency
rare alone but can be found in combination with other B vitamin deficiencies
- Can lead to microcytic anemia - red blood cells are small and do not properly transport oxygen
- symptoms include fatigue, lethargy, dry and cracked lips and a swollen tongue
- people with kidney issues, alcohol dependency and autoimmune disorders are at higher risk for deficiency
27
B6 toxicity
- Not common from food but can be seen from prolonged supplementation of > 1000mg per day can lead to loss of control over body movements
28
B6 special uses
implicated in improving cognitive function and reducing cancer risk
29
AI for B7 - Biotin
30mcg
30
Biotin functions
generic name for 5 vitamins
- involved in metabolism of carbohydrates, lipids, and proteins
- Involved in cell signalling and DNA structure and function
31
Special uses for biotin
can help with compromised hair, nail and skin health
32
Sources of biotin
beef liver, chicken, tuna, pork sunflower seeds, sweet potatoes, almonds, spinach, broccoli
33
Biotin deficiency
- biontinidase caused by genetic condition
- Chronic alcohol abuse can lead to deficiency : hair loss, red eyes, and rashes around eyes, nose and mouth
- In serious cases can lead to seizures, depression and decreased muscle tone and strength
34
RDA and UL of vitamin B9 folate
RDA 400mcg
UL 1000 mcg
35
folate functions
- coenzyme in the synthesis of DNA and RNA
- involved in the metabolism of amino acids
- involved in the conversion of homocysteine to methionine
36
sources of folate
beef live, spinach, legumes, asparagus, Brussel sprouts, avocados, fortified cereals and grains
37
folate deficiency
rare in non-pregnant individuals
- can causes neural tube deficits in the fetuses on pregnant women - can lead to miscarriage or neural complications such as spina bifida and anencephaly
megaloblast anemia - red blood cells are immature, large, misshapen, and unable to properly perform (due to inability to synthesize DNA during RBC production) leads to tiredness, weakness, and heart irregularities
- Autism spectrum disorder
38
Folate toxicity
generally well tolerated
- May include nausea, bloating, decreased appetite and difficulty sleeping
- Can mask b12 deficiency as it prevents megaloblastic anemia
39
what is the RDA of vitamin 12 cobalamin
2.4 mcg
40
Vitamine b12 functions
- required for DNA synthesis
- the formation of mature red blood cells
- brain function
- coenzyme for the conversion of homocysteine to methionine
- fat and protein metabolism
41
Special uses for B12
reduced the risk of dementia
42
Absorption of B12
hydrochloric acid in the stomach helps to release b12 from food
Intrinsic factor (IF) is also released in the stomach and is required for the absorption of b2 in the small intestine
Atrophic gastritis results in the breakdown of the stomach lining and a lack of IF
43
Sources of B12
shellfish, fish, beef liver, not typically found in plants
44
B12 deficiency
- Megaloblastic anemia: fatigue, lethargy, constipation, and loss of appetite
- can also lead to balance issues, depression, poor memory, and confusion
45
B12 toxicity
No UL
46
RDA and UL of Vitamin C - Ascorbic acid
- crucial in the formation of collagen
- metabolism of protein
- antioxidant
- can increase iron absorption
47
Describe antioxidants
Help reduce the activity of free radicals, reactive molecules that have an unpaired electron and can steal electrons from other molecules such as DNA and cell membranes. They work by donating an electron neutralizing the free radicals
48
Special uses for vitamin c
- Immune system
- chronic disease prevention: no evidence but believed to reduce cancer and CVD
49
Sources of vitamin C
citrus fruits (oranges, grapefruits, kiwis and lemons) tomatoes, strawberries, broccoli, Brussel sprouts, cauliflower, and fortified in cereals and grains
50
Vitamin C deficiency
- Rare
- Can lead to scurvy which causes fatigue and gum inflammation
- can also effect collagen formation, wound healing, and joint integrity
51
Vitamin C toxicity
rare
- mild symptoms, diarrhea, nausea, abdominal cramps
52
Fat soluble vitamins
53
RDA and UL of vitamin A
900 mcg for men
700 msg for women
UL 3000 mcg
54
What are the forms of vitamin A
- Provitamin A is found in plants and its vitamins are collectively known as carotenoids (not active)
- Performed vitamin A is found in its almost-active form retinol and retinal ester
- The active form is retinal and retinoic acid
55
Functions of vitamin A
- retinal binds to opsin to form rhodopsin, a visual pigment found in the retina
- Gene expression helping to turn certain genes on or off affecting whether DNA is transcribed into proteins
- Formation of T cells
- Antioxidant
56
Special uses of vitamin A
- Promotes healthy skin by switching on the genes that cause immature skin cells to become mature and healthy
- Overuse can cause skin irritation, burning, scaling and dermatitis
57
Vitamin A deficiency
-xerophthalmia: abnormal dryness of the eye that affects the bodies ability to produce tears --> can lead to breaks in the cornea
- Night blindness is an early sign of xerophthalmia
- most prevalent in pregnant women and children
57
Sources of vitamin A
found in animal products and many orange and leafy green plants. Beef liver, fish oils, milk and eggs, spinach, carrots, pumpkin, cantaloupes, red peppers
58
Vitamin A toxicity
- Skin turns orange
- If over consuming supplements may experience pressure around brain, dizziness, nausea, headaches and can be fatal
59
RDA and UL of Vitamin D
RDA: 15mcg
UL 100 mcg
60
Functions of vitamin D
- Vitamin D2 and D3 are critical for maintaining calcium homeostasis (increase calcium absorption in the digestive tract
- Bone health
- cellular growth
- immune function
- reduction of inflammation
61
Special uses for vitamin D
- potential role in cancer protection no evidence
62
Sources of vitamin D
fatty fish (salmon, tuna, mackerel) fish oils. orange juice, milk (if fortified)
- Sun increases vitamin D synthesis
63
Vitamin D deficiency
- Can lead to rickets in children, lack of bone mineral density that leads to soft bones (causes legs to bow outwards)
- Can lead to osteomalacia in adults, a softening of bones due to decreases in bone mineralization, also causes muscle weakness, difficulty walking, and pain in bones and joints
- Osteoporosis
- Risk factors: darker skin, lactose intolerance, vegetarianism
64
Vitamin D toxicity
Over-supplementation --> leads to anorexia, weight loss, increased urination and irregular heart rhythms
65
RDA and UL of Vitamin E
RDA 15 mg
UL 1000 mg
66
Functions of vitamin E
- antioxidant
- immune functioning
- cell signalling
- gene expression
67
Special uses for vitamin E
- potential decrease in risk for cancer and CVD
68
Sources of vitamin E
vegetable oils, fatty shellfish, fatty plants such as nuts, seeds, fortified cereals. and nut butter
69
Vitamin E deficiency
- Compromised fat absorption --> gastric bypass surgery, Crohn's disease or cystic fibrosis
- Symptoms: peripheral neuropathy, movement difficulties, muscle disorders, and an impaired immune system
70
Vitamin E toxicity
- lung issues in those that vape
71
AI of vitamin K
120 mcg in men
90 mcg in women
72
Functions of vitamin K
- coagulation - blood clotting via the synthesis of the protein prothrombin which is then activated into thrombin. Thrombin converts fibrinogen to fibrin which helps blood clot together
73
Sources of vitamin K
ready green vegetables - spinach, broccoli, as well as oils and nuts. Can be found in animal products such as liver, ham, cheese and milk
74
Vitamin K deficiency
- newborns are at risk, and can causes issues in bone mineralization
75
Vitamin K toxicity
no UL
