Vitamins Flashcards
1
Q
what are vitamins?
A
Vitamins are micronutrients (organic compounds) required by the body to carry out a range of normal functions
2
Q
what are factors that determine the amount of vitamin that are readily available?
A
– Source (animal vs. plant)
– Sunlight
– Moisture
– Growing conditions
– Plant’s maturity at harvest
– Packaging and storage
3
Q
what are reasons why we wouldn’t get enough vitamins?
A
- dietary interactions
- drug interactions
- physiological state
- disease
- genetic
- food processing
4
Q
what is a provitamin?
A
a substance that may be converted within the body to a vitamin (is the inactive form)
5
Q
what are the water-soluble and the fat-soluble vitamins?
A
- water: B1, B2, B3, B5, B6, B7, B9, B1, C
- fat: A, D, E, K
6
Q
differences in absorption of water-soluble and fat-soluble vitamins.
A
fat:
- are solubilized by bile salts (make micelles)
- released at enterocyte brush border membrane
- incorporated into chylomicrons
- secretion into lymphatics and ultimate uptake by the liver (can accumulate in body)
water:
- can go through enterocytes
- go to blood vessels
- doesn’t stay long since it secreted in urine
7
Q
what are the active and precursors of vitamin A?
A
- active: retinoids
- pre: carotenoids
8
Q
vitamin A is important for:
A
- Vision: night and day
* Becomes part of the retina
* Keeps eye surface healthy
* Allows night and color vision - Immune function
* Produce immune cells to fight microorganisms - Cell Production and differention
* Regulates production of enzymes, blood carrier proteins,
And structural
Proteins (like those in the skin) - Skin
* Needed to replace epithelial cells of your skin - Reproduction
* Keep reproductive tracts healthy
* Women:maintain fertility; Men:Sperm production
* Embryo development - Bones
* Helps produce bone cells
* Required For bone remodeling a increase In osteoclasts
9
Q
how does vitamin A affect vision?
A
- is a precursor of rhodopsin, the photopigment
found in rods within the retina of our eye that helps us to see at night. - Without vitamin A, “night blindness” occurs
10
Q
what are sources of vitamin A?
A
- fruits and vegetables (carrot and sweet potato very high)
- liver
- oat/bran
- milk
11
Q
what are the effects of vitamin A deficiency?
A
- eyes: Xerophthalmia (blindness)
- skin: hyperkeratosis
- immune: vulnerable to infection
- other: Growth retardation, bone deformations, defective teeth, and kidney stones
12
Q
what are the effects of vitamin A toxicity?
A
- symptoms: Fatigue, vomiting, abdominal pain, bone and joint pain, loss of appetite, Skin disorders, headache, blurred or double vision, and liver damage
- is a teratogen
- causes skin discoloration
- acne treatment
13
Q
how is vitamin D activated?
A
by liver and kidney
14
Q
what are the functions of vitamin D?
A
- Essential for bone health (important for calcium absorption)
- Helps regulate Insulin formation and secretion
15
Q
what are sources of vitamin D?
A
- exposure to sunlight
- fortified foods (milk, cereals)
- oily fish, egg yolk, liver
- supplements
16
Q
what happens with vitamin D deficiency and toxicity?
A
- deficiency: rickets in children, osteomalacia and osteoporosis in adults
- toxicity: hypercalcemia
17
Q
what are the different forms of vitamin E?
A
- 8 similar compounds but only alpha-tocopherol required for humans
18
Q
what are the functions of vitamin E?
A
- antioxidant (protect cell membrane form free radicals)
19
Q
what is the recommended daily intake of vitamin E?
A
- 15mg/day for adult
- 19mg/day for breastfeeding
20
Q
what are food sources of vitamin E?
A
-nuts/seeds
- vegetable oil
- whole grain/wheat germ oil
- fruits and vegetables
- animal products
21
Q
when does vitamin E deficiency occurs? what about toxicity?
A
- deficiency: occurs with fat malabsorption or rare genetic disorders
- toxicity: nontoxic and adverse effects have not been found, but can interfere with blood clotting and causes lung injury when inhaled
22
Q
what are the forms of vitamin K?
A
K1 and K2
23
Q
what are the functions of vitamin K?
A
- blood clotting (necessary for the synthesis of thrombin)
- bone health
24
Q
what are the dietary recommendations of vitamin K?
A
- men: 120 mg/day
- women: 90 mg/day
25
what are the food sources of vitamin K?
- green vegetables
- plant oils
- intestinal bacteria
26
what happens with vitamin K deficiency and toxicity?
- deficiency: rare in healthy people, newborns at risk
- toxicity: rare, can interfere with anticoagulant medications
27
what are the functions of thiamin (B1)?
- coenzyme in energy metabolism
- part of the coenzyme thiamin pyrophosphate (TPP): helps break down glucose, make RNA/DNA, helps power protein, help synthesize and regulate neurotransmitters
28
what is the name of vitamin B1?
thiamin
29
what are dietary recommendations of thiamin (B1)?
- men: 1.2 mg/day
- women: 1.1 mg/day
- pregnancy: 1.4 mg/day
- breastfeeding: 1.5 mg/day
30
what are the food sources of thiamin (B1)?
- pork
- legumes/nuts/seeds
- fish/seafood
- grain product
- cooking reduces content
31
what happens with thiamin (B1) deficiency and toxicity?
- deficiency: beriberi (overall profound muscle weakness and nerve destruction -- milder symptoms include headache, irritability, depression, and loss of appetite)
- toxicity: no reports of toxicity
32
what is the name for vitamin B2?
riboflavin
33
what are the functions of riboflavin (B2)?
-coenzyme in energy metabolism
- supports antioxidants
34
what are the food sources of riboflavin (B2)?
- milk/dairy products
- enriched grains
- eggs
35
____ breaks down riboflavin which is why ___________
- light
- foods high in riboflavin are stored in opaque containers (like milk)
36
what happens with riboflavin deficiency and toxicity?
- deficiency: ariboflavinosis (occurs mostly in chronic alcoholism)
- skin disorders, hyperemia (excess blood) and edema of the mouth and throat, angular stomatitis (lesions at the corners of the mouth), cheilosis (swollen, cracked lips), hair loss, reproductive problems, sore throat, itchy and red
- toxicity: no reported cases
37
what are the functions of niacin (B3)?
- coenzyme in energy metabolism
- supports fatty acid synthesis
38
what is the name for vitamin B3?
niacin
39
what are the food sources of niacin (B3)?
- can be made from tryptophan
- whole and enriched grains
- meat, poultry, fish, nuts, and peanuts
40
what happens with niacin (B3) deficiency and toxicity?
- deficiency: pellagra (dermatitis, diarrhea, dementia, and death) and can worsen if also deficient in B1, B6 and iron
- toxicity: high doses used to treat high blood cholesterol (skin flushing, liver damage)
41
what is the name of vitamin B6?
pyridoxine
42
what are the functions of pyridoxine (B6)?
- PLP coenzyme in protein and AA metabolism, and gluconeogenesis
- produce non-essential AA
- produce neurotransmitters and hemoglobin
- helps to lower blood levels of homocysteine
43
what are food sources of vitamin B6?
- meat,fish, poultry, fortified meat substitutes
- bananas
- sunflower seeds
44
what happens with vitamin B6 deficiency and toxicity?
- deficiency: microcytic hypochromic anemia, heart disease (high homocysteine), damage nervous system (depression, headache, confusion, convulsion)
- toxicity: can cause subtle neurological damage, upset stomach, headache, sleepiness, tingling/prickling/burning sensation
45
what are the functions of folate (B9)?
- coenzyme in DNA synthesis and cell division
- coenzyme in AA metabolism
- needed for normal RBC maturation
- works with B6 and B12 to help control homocysteine levels
46
what is the name for vitamin B9?
folate
47
what are the food sources of folate (B9)?
- fortified cereals/enriched grains
- green leafy vegetables
- orange juice
- sunflower seeds
- legumes
48
what happens with folate (B9) deficiency and toxicity?
- deficiency: anemia and diarrhea, birth defects (spina bifida), heart disease
- toxicity: can mask vitamin B12 deficiency with folate supplements, hypersensitive people may suffer hives or respiratory distress
49
what is the name of vitamin B12?
cobalamin
50
what are the sources of vitamin B12?
- only animal foods: meats, liver, milk, eggs
- fortified foods
51
what are the functions of vitamin B12?
- needed for normal folate function (DNA and RBC synthesis, metabolize homocysteine)
- maintain myelin sheath around nerves
52
vitamin B12 absorption requires __________
intrinsic factor
53
what happens with vitamin B12 deficiency and toxicity?
- deficiency: can lead to pernicious anemia (resulting in nerve damage), RBCs can look enlarges
- toxicity: none
54
what are the functions of vitamin B5?
- component of coenzyme A
55
what are the food sources of vitamin B5?
- widespread in food
- reduced by freezing, canning, and refining
56
what happens with vitamin B5 deficiency and toxicity?
rare
57
what is the name of vitamin B7?
biotin
58
what are the functions of biotin (B7)?
- coenzyme
- AA metabolism
- fatty acid synthesis
- release of energy from fatty acids
- DNA synthesis
59
what are the food sources of biotin (B7)?
- cauliflower
- liver
- peanuts
- cheese
- raw egg whites binds biotin and prevents absorption
60
what are the functions of vitamin C?
- antioxidant
- collagen synthesis
- enhances the absorption of iron from plant foods
- make other essential compounds
61
what are the food sources of vitamin C?
- fruits (citrus, strawberries, kiwi)
- vegetables: broccoli, tomatos, potatoes, cabbage, leafy green, peppers
62
what happens with vitamin C deficiency and toxicity?
- deficiency: scurvy
- toxicity: may cause GI distress in high doses
