Chapter 9 and 10: Vitamins Flashcards
1
Q
vitamins are essential nutrients
A
called micronutrients
2
Q
fat soluble vitamins
A
- absorbed with dietary fat and can be stored in the body
- easily stored in fat upon absorption
- should be taken with food to absorb them
- ADEK
3
Q
water soluble vitamins
A
- absorbed with water and enter the bloodstream directly
- not stored in the body, but excesses can still be harmful
- excreted through the urine
- similar to how we absorb carbs/proteins
- B vitamins and vitamin C
4
Q
vitamin absorption
A
- similar to how we absorb macronutrients
- vitamins bound to proteins are released in the stomach
- in the SI, the fat soluble vitamins are transported into the intestinal cells as part of micelles
- once inside the intestinal cells, fat soluble vitamins are packaged with fat and other lipids into a chylomicron
- the chylomicrons travel through the lymph system to the main circulation
- water soluble vitamins are absorbed directly into the portal vein from the SI through diffusion
5
Q
vitamins as antioxidants
A
- some vitamins function as antioxidants, which counteract oxidation by neutralizing substances called free radicals
- vitamins A, E, C, and beta-carotene
6
Q
free radicals
A
unstable oxygen containing molecules that can damage the cells of the body and possibly contribute to increased risk of chronic diseases
7
Q
vitamins can be damaged by water, heat, and air
A
- air exposure can destroy both water and fat soluble vitamins
- store in airtight containers
- a little water is enough for cooking veggies
- steaming and microwaving results in the least amount of nutrient loss
- heat will destroy water soluble vitamins (especially vitamin C)
- reduce cooking times
8
Q
bioavailability
A
the degree to which a nutrient is absorbed from foods and used in the body
9
Q
bioavailability of vitamins
A
- vitamins differ
- vitamins can be destroyed by air, water, and heat
- provitamins can be converted to vitamins by the body
- if deficient in one vitamin, can absorb higher levels of it to counteract
10
Q
provitamins
A
- provitamins are substances found in foods that are not in a form directly usable by the body, but that can be converted into an active form once they are absorbed
- think of these as precursors to the active form of the vitamin
- biologically inactive compounds
11
Q
preformed vitamins
A
are vitamins found in foods that are already in the active form and do not undergo conversion in the body
12
Q
vitamin A
A
- fat soluble vitamin
- same plants contain provitamin A compounds which are converted to retinol in the body
- preformed vitamin A found primarily in animal food
13
Q
provitamin A
A
beta carotene and carotenoids
14
Q
preformed vitamin A
A
retinyl ester
15
Q
food sources of provitamin A
A
- plant sources
- carrots, kale, spinach, apricots, broccoli, pumpkin
16
Q
food sources of preformed vitamin A
A
- animal sources
- eggs, fish, liver
17
Q
primary functions of vitamin A
A
- vision
- protein synthesis and cell differentiation
- reproduction
- bone healthy
- immune system
- may help fight cancer as carotenoids are antioxidants
18
Q
vitamin A toxicity
A
- excess amounts of preformed vitamin A can be toxic
- occurs via supplements not food intake
- hypervitaminosis A: liver damage and death
- during pregnancy can conception, can cause birth defects in the face, skull, and CNS
- can potentially increase the risk for osteoporosis and bone fractures in adults
19
Q
vitamin A deficiency
A
- chronic deficiency can cause night blindness
- prolonged can lead to xerophthalmia (disease that causes dry eyes)
- leading cause of blindness in children in most developing countries
- can lead to keratinization of the epithelial tissues
20
Q
vitamin D functions
A
- promotes calcium absorption
- needed for proper bone growth
- reduces inflammation
- modulates cell growth
- regulates immune and neuromuscular function and glucose metabolism
- reduces the risk of heart disease (by reducing cholesterol and lowering blood pressure)
- helps the body regulate blood sugar in type 2 diabetes
21
Q
RDA for vitamin D
A
600 IU
22
Q
vitamin D food sources
A
fatty fish, fish liver oils, fortified foods (milk, yogurt, orange juice, cereal), egg yolks, cheese, mushrooms
23
Q
environmental sources of vitamin D
A
- the human body can synthesize vitamin D
- requires exposure to sunlight
- UV radiation reacts with a form of cholesterol in the skin to produce vitamin D3
- D3 can then undergo hydroxylation by the liver and kidney and eventually form active vitamin D
- season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are some factors that affect UV radiation exposure and vitamin D synthesis
24
Q
location on earth effect on vitamin D
A
- the closer to the equator you live, the easier it is for your body to synthesize vitamin D
- latitudes above 37 degrees N and below 37 degrees S the equator don’t get enough UV radiation energy from the sun (only during the summer)
25
Q
vitamin D toxicity
A
- very rare
- usually caused by excessive intake of supplements
- very difficult to reach toxic levels through sun exposure and diet alone
- can cause high levels of calcium in the blood (hypercalcemia) which lead to mild symptoms like nausea, vomiting, and muscle weakness
- severe symptoms include renal failure, calcification of tissues, cardia arrhythmias, and death
26
Q
vitamin D deficiency
A
- more likely to develop this if intake is under the RDA, there is little sun exposure, or there is insufficient absorption of vitamin D
- leads to weak bones, osteomalacia in adults, rickets in children, pain, hypocalcemic seizures, tetanic spasms, and dental deformity
27
Q
osteomalacia
A
softening of the bones in adults
28
Q
rickets
A
softening and weakening of the bones in children (bowed legs)
29
Q
vitamin E functions
A
- antioxidant: protects against free radicals
- keeps immune system strong
- helps form red blood cells
- protects against clotting
- helps the body use vitamin K
- cells use it to interact with each other
30
Q
vitamin E food sources
A
vegetable oils, nuts, seeds, green leafy veggies, fortified cereals, juices, spreads, and margarine
31
Q
vitamin E toxicity
A
- could increase risk of prostate cancer
- high doses are more dangerous after a heart attack or stroke
- oral use can cause diarrhea, nausea, intestinal cramps, fatigue, headaches, blurred vision, and increased creatine in the urine
- generally safe
32
Q
vitamin E deficiency
A
- very rare
- linked to diseases like Crohn’s disease, cystic fibrosis, and rare genetic diseases
- needs fat to be absorbed
- can cause nerve and muscle damage, loss of body movement control, muscle weakness and vision problems
- weakened immune system
33
Q
vitamin K functions
A
- known as the clotting vitamin
- needed to make certain proteins in the liver that cause blood to clot
- reduces risk of bleeding in liver disease
- body needs vitamin K to use calcium to build bones
- higher levels of vitamin K = greater bone density
- improves bone health and reduces risk of fractures
34
Q
vitamin K food sources
A
- green leady veggies (spinach, kale, broccoli)
- meat and dairy (cheese, chicken, eggs)
- fruits (blueberries and grapes)
- vegetable oils
- soybeans
- fortified meal replacement shakes
35
Q
vitamin K toxicity
A
- extremely rare
- most common in formula fed infants
- formula is fortified with significantly higher levels of vitamin K compared to breast milk
- can cause hemolytic anemia and jaundice
36
Q
vitamin K deficiency
A
- uncommon in healthy adults because vitamin K is widespread in foods, the vitamin K cycle conserves it, and bacteria in the large intestine synthesizes vitamin K
- adults at risk include those taking vitamin K antagonists, people with significant liver damage or disease, and people with fat malabsorption disorders (inflammatory bowel disease and cystic fibrosis)
- newborn infants have low vitamin K status because vitamin K transport across the placental barrier is limited, liver storage of vitamin K is very low, vitamin K cycle may not be full functioning yet, and they have immature gut flora
- deficiency in adults can result in impaired blood clotting (easy bruising or bleeding, increased risk of nosebleeds or bleeding gums, blood in the urine or stool, heavy menstrual bleeding) and weakened bones or increased risk of fractures
- deficiency in infants can result in vitamin K deficiency bleeding (VKDB) and an intracranial hemorrhage
37
Q
vitamin B1
A
thiamin
38
Q
vitamin B1 functions
A
- helps change CHOs in the body into energy, playing a crucial part in the growth, development, and function of cells
- essential for metabolizing pyruvate
- muscle contractions and overall muscle health because it provides energy from the muscle to the tissue
- aids in the synthesis of neurotransmitters, which facilitate communication between nerve cells
39
Q
vitamin B1 food sources
A
- found naturally in meats, fish, and whole grains
- beans, lentils, and enriched rice
40
Q
vitamin B1 toxicity
A
- non toxic
- high levels are flushed out through the urine
41
Q
vitamin B1 deficiency
A
- rare
- can arise from a lack of thiamin intake, decreased absorption, or increased B1 loss through the urine
- severe deficiency can lead to Beriberi
- can cause Wernicke-Korsakoff syndrome in alcoholics
42
Q
Beriberi
A
muscle loss and diminished feeling in the hands and feet
43
Q
vitamin B2
A
riboflavin
44
Q
vitamin B2 functions
A
- essential component of FMN and FAD
- energy production, cellular function, growth and development, metabolism of fats, drugs, and steroids
- helps metabolize CHOs, fats, and proteins into glucose
- helps maintain normal levels of homocysteine
- antioxidant for proper functioning immune system
45
Q
vitamin B2 food sources
A
primarily found in mostly meat, dairy, and fortified foods but also in some nits and green veggies
46
Q
vitamin B2 toxicity
A
- generally considered safe even at high doses
- excess B2 can be excreted through the urine
- some symptoms include increased sensitivity to light, yellow or orange urine, burning or prickling sensations, and itching
47
Q
vitamin B2 deficiency
A
- can impair the metabolism of other nutrients, especially other B vitamins, through diminished levels of flavin coenzymes
- if severe/prolonged: anemia and cataracts can develop
- symptoms include skin disorders, hyperemia (excess of blood in the vessels supplying an organ), hair loss, and degeneration of the liver/nervous system
48
Q
vitamin B3
A
niacin
49
Q
two active forms of vitamin B3
A
nicotinic acid and nicotinamide
50
Q
vitamin B3 can be converted to active coenzymes
A
NAD+ and NADP+
51
Q
bioavailability of vitamin B3
A
- less available in plant foods (like wheat and corn)
- more available in dairy and meat products
52
Q
vitamin B3 food sources
A
meats, fish, poultry, enriched and fortified grains and cereals, avocados, and AA tryptophan
53
Q
vitamin B3 functions
A
- acts as a coenzyme in Redox reactions for macronutrients, and folate and vitamin C metabolism
- plays a role in skin health and functioning of the GI tract
- in therapeutic doses can lower total cholesterol and triglycerides and raise HDL cholesterol
54
Q
vitamin B3 toxicity
A
- none reported from normal dietary intake
- excess supplementation can cause reddish coloring of face, arms, and chest; vomiting and nausea; heartburn; liver toxicity; and elevated BG levels
55
Q
vitamin B3 deficiency
A
-Pellagra (disease of the 4 Ds)
- dermatitis, diarrhea, dementia, death
56
Q
vitamin B5
A
pantothenic acid
57
Q
vitamin B5 functions
A
- key part of the compound coenzyme A which is used to make acetyl CoA
- fat: synthesizes fatty acids and converts to energy
- CHO: converts pyruvate to acetyl CoA
- protein: converts amino acids to substrates in the TCA cycle
- synthesis of cholesterol, steroid hormones, and the neurotransmitter acetylcholine
58
Q
vitamin B5 food sources
A
- widespread in a variety of foods
- whole grain cereals, nuts/legumes, peanut butter, meat, milk, eggs
- mushrooms, cauliflower, tomatoes, salmon, broccoli, avocado, chicken liver, sunflower seeds
- can be destroyed by heat, so processed foods are lower than fresh foods
59
Q
vitamin B5 toxicity
A
none known
60
Q
vitamin B5 deficiency
A
- rare
- may experience fatigue, nausea and vomiting, numbness, and muscle cramps
61
Q
vitamin B6 functions
A
- metabolism: involved in over 100 enzyme reactions that help the body convert food into fuel, metabolize fats/protein, and break down glycogen
- brain development during pregnancy and infancy
- helps the body produce neurotransmitters, which carry signals between nerve cells
- blood: helps make hemoglobin, which carriers oxygen in red blood cells and keeps blood sugar levels normal
- immune function: helps the body produce antibodies and lymphocytes (important for fighting infections and viruses)
- hormones: helps produce serotonin and norepinephrine which affect mood and melatonin
- helps regulate the body’s clock
- supplements can treat a genetic form of anemia
62
Q
vitamin B6 food sources
A
tuna, salmon, soybeans, pistachios, sunflower seeds, liver and organ meat, turkey and other poultry, potatoes, white rice, and non-citrus fruits
63
Q
vitamin B6 toxicity
A
- caused by excessive supplementing and prolonged use
- if combined with cycloserine, an antibiotic to treat tuberculosis, the urinary excretion of the active form of B6 increases and can be harmful
- results in peripheral neuropathy (numbing sensation due to nerve damage), dermatoses (skin defects and lesions), photosensitivity (skin becomes sensitive to light), ataxia (loss of muscle control), and heartburn and dizziness
64
Q
vitamin B6 deficiency
A
- skin/mouth: itchy rashes, scaly lips, cracks at the corners of the mouth, swollen tongue
- mental health: depression, confusion, irritability
- anemia: lack of healthy red blood cells
- infants: irritability, extremely sensitive hearing, seizures
- weakened immune function
65
Q
vitamin B12 functions
A
- red blood cell production
- maintenance of nerve cells
- prevention pf anemia
- makes DNA
66
Q
vitamin B12 food sources
A
- meat (red meat, chicken, lamb)
- fish (salmon, clams, tuna)
- dairy (milk, yogurt, cheese)
- eggs
- plant sources
- doesn’t naturally occur but can be fortified (year and breakfast cereals)
67
Q
vitamin B12 toxicity
A
none
68
Q
vitamin B12 deficiency
A
- main population at risk: vegans and vegetarians because B12 doesn’t normally occur in whole plant foods and people with digestive tract issues because B12 is synthesized and utilized by bacteria in the but microbiome
- potential effects include anemia, low white blood cell count, dementia, and fatigue
69
Q
vitamin C where the C stands for
A
ascorbic acid which means anti-scurvy
70
Q
vitamin C functions
A
- helps protect cells and keep them healthy
- maintaining healthy skin, blood vessels, bones, and cartilage
- helps with wound healing
- required for the biosynthesis of collagen and helps with protein digestion
71
Q
vitamin C food sources
A
- found in many fruits and veggies
- oranges aren’t the best source
72
Q
vitamin C toxicity
A
- diarrhea, nausea, heartburn, stomach cramps, headache, and vomiting
- severe toxicity leads to bone spurs, kidney stones, seizures, and muscle pain
73
Q
vitamin C deficiency
A
- symptoms of scurvy include inflamed and bloody gums, poor wound healing, spontaneous hemorrhages, coiled hair, and arthritis
- in children it can cause pain in movement, stunted growth, anemia, and anorexia
74
Q
biotin
A
- a B water soluble vitamin
- contains sulfur (double rings and a side chain)
75
Q
biotin functions
A
- coenzyme in energy metabolism (replenishes oxaloacetate from pyruvate)
- DNA replication and transcription of genes
- cell development and growth (maintenance of healthy hair, skin, and nails)
- synthesis of fatty acids
- amino acid metabolism
76
Q
biotin food sources
A
peanuts, yeast, liver and organ meats, bacteria in the GI tract, egg yolks, whole grains, fish, carrots, and soy beans
77
Q
biotin toxicity
A
rare
78
Q
biotin deficiency
A
- rare
- seen with overconsumption of raw egg whites (>12/day for a prolonged time)
- avidin in raw egg whites can bind to biotin and cause deficiency symptoms
79
Q
folate
A
a B water soluble vitamin
80
Q
folate functions
A
- transfers single/carbon compounds to form new compounds
- DNA and amino acid synthesis
- homocysteine metabolism
- may prevent cancer and heart disease
- assists in neural tube development
81
Q
folate food sources
A
- folic acid (synthetic form) is added to foods and supplements and is more bioavailable
- folate is destroyed by exposure to heat and light
- raw foods have more folate than cooked foods
- some foods contain enzymes that inhibit folate availability (beans, legumes, cabbage)
82
Q
what can impact the ability to convert folic acid to folate
A
the MTHFR gene mutation
83
Q
folate toxicity
A
- rare
- seen from supplements
84
Q
folate deficiency
A
- could result in neural tube defects, anencephaly, and spina bifida
- anencephaly: fatal condition where a baby is born without parts of the brain and skull
- spina bifida: birth defect where the neural tube doesn’t close completely during pregnancy, resulting in an incomplete developed spine in the baby
85
Q
choline
A
not classified as a vitamin, it’s a vitamin-like substance
86
Q
choline functions
A
- part of the phospholipids that makes up the cell wall
- liver metabolism
- precursor to acetylcholine
- fetal brain development
87
Q
choline food sources
A
- animal sources, milk, liver, eggs, peanuts
- especially in egg yolks
88
Q
choline toxicity
A
excess from supplements can cause vomiting and hypotension (low BP)
89
Q
choline deficiency
A
- rare
- more likely in pregnant women
90
Q
inositol
A
a vitamin-like substance
91
Q
inositol functions
A
- keeps cell membranes healthy
- may play a role in insulin regulation in women with PCOS and regulation of sex hormones
92
Q
inositol food sources
A
found in plant sources
