Chapter 8 Flashcards
water-soluble vitamins
what are the water-soluble vitamins?
B-vitamins
Thiamin (B1)
Riboflavin (B2)
Niacin (B3)
Pantothenic acid (B5)
Pyridoxine (B6)
Biotin (B7)
Folate (B9)
Cobalamin (B12)
Other water-soluble vitamins
Ascorbic acid (Vitamin C)
Choline (maybe)
what is the function of co-enzymes?
-The B vitamins function as co-enzymes
(small molecules that enable enzymes
to function)
* Coenzymes attach at the active site of
the enzyme
* Co-enzymes participate in biochemical
reactions involving energy release or
catabolic/anabolic reactions
Roles of B vitamins
-The metabolism of energy-yielding
nutrients (CHO, fat, protein)
requires vitamin input
* Because B-vitamins are readily
excreted from the body and have
limited storage, they should be
consumed daily
* An occasional lapse causes no
harm
consequences of grain processing
-When germ, bran and husk layers
are discarded (only starchy
endosperm remains)
* Leads to loss of B-vitamins and other
vitamins and minerals
* Bread and cereal products are then
enriched with four B vitamins
(thiamin, riboflavin, niacin and folic
acid) – also iron
* Increased glycemic response
* Decreased fiber intake
major sources of thiamin
-Protein and grain groups
* Whole grains, pork,
read-to-eat breakfast
cereals, enriched
grains, peas, orange
juice, organ meats,
dried beans
Thiamin deficiency is disease
is called ‘beriberi’
thiamin (main functions)
helps the body release energy from carbs. Serves as part of the coenzyme thiamin pyrophosphate to participate in ATP-producing pathways. Contributes to chemical reactions that synthesize RNA, DNA, and neurotransmitters. Assists the body in the breakdown of carbohydrates and protein
Thiamin (recommendations)
RDA Men: 1.2 mg
RDA Women: 1.1 mg
D.V.: 1.2 mg
UL: none
Riboflavin (main functions)
-easily destroyed by sunlight
-forms coenzymes flavin dineucleotide and flavin mononucleotide to participate in metabolic pathways. Through these coenzymes, contribute to growth, development, and metabolism of drugs and nutrients. contributes to the metabolism of of vitamins and minerals
-is stored in the liver, heart, kidneys in small amounts
riboflavin (Recommendations)
RDA Men: 1.3 mg
RDA Women: 1.1 mg
DV: 1.3 mg
UL: none
Riboflavin in foods
sour cream, orange juice, asparagus, yogurt, cereal, beef liver
Riboflavin (deficiency)
known as ariboflavinosis- inflammation in the tongue and mouth, dermatitis, cracked skin around mouth
Niacin (main functions)
forms compunds nicotinamide and nicotinic acid, which contributes to cellular metabolic pathways. enzamatic forms of niacin contribute to the metabolic processes that form ATP. Plays a role in maintenance of some of the body’s antioxidant systems and maintenance of genome integrity and to regulation of gene expression
Niacin (Recommendations)
RDA Men: 16 mg
RDA Women: 14 mg
DV: 16 mg
UL: 35 mg (nicotinic acid forms)
Niacin (food groups)
sour cream, banana, baked potato, soy milk, foretified cereal, beef liver
Niacin B-3 (deficiency)
-pellegra means “rough and painful skin”
-symptoms: diarrhea, dermatitis, dementia, death
-common in places where corn was staple with low protein diet
-tryptophan can turn into niacin
-soaking corn in alkaline solution releases niacin
Niacin B-3 (toxicity)
-very high doses can lower blood triglyceride and cholesterol levels (from 500-2000 mg/day)
-side effects: niacin flush (rapid heartbeat, flushing)
-seen when intakes are at 300 mg
-UL is 35 mg
Pantothenic acid B-5 (main functions)
-contributes to the synthesis of coenzyme A (coA). Through CoA, enables chemical reaction that allow release of energy from macronutrients
-activates fatty acids for energy production
-contributes to fatty acid synthesis
Pantothenic Acid B-5 (recommendations)
AI: 5 mg
DV: 5 mg
UL: none
Pantothenic Acid B-5 (food sources)
mayo, orange juice, mushrooms, milk, whole wheat, sunflower seeds
Pantothenic Acid B-5 (deficiency)
- hard to detect bc similar to other B-vitamin deficiencies
Vitamin B-6 (pyridoxine) (main functions)
-contributes to several enzymes involved in carbohydrate, protein, and lipid metabolism
-serves as a building block for coenzyme for PLP, which is needed in synthesis nonessential amino acids.
-regulates homsysteine metabolsim
-contributes to the synthesis of neurotransmitters
-can be stored in liver (along with B-12)
-pyridoxine, pyridoxal, pyridoxamine
Vitamin B-6 (pyridoxine) (food sources
-in every food sources but mainly animal foods and fortified cereals
-heating freezing foods can easily destroy vitamin B-6
Vitamin B-6 (pyridoxine) (recommendations)
RDA: 1.3 mg
DV: 1.7 mg
UL: 100 mg
Vitamin B-6, B-12 (toxicity)
can lead to permanent nerve damage
Biotin (Vitamin B-7) (main functions)
-aids in chemical reactions
-contributes to developmetn of coenzymes that aid in the synthesis of of glucose and fatty acids
-related coenzymes also assists in the breakdown of of certain amino acids
-plays role in histone modification, thus contributing to gene regulation
-biotin deficiencies are rare bc as the gut microbiota synthesize some biotin that the body can absorb
-biotin bioavailability is altered significantly in different foods bc due to the nutritent being bound to proteins: ie eggs
Biotin B-7 (recommendations)
AI: 30 mcg
DV: 30 mcg
UL: none
Folate B-9 (main functions)
-DNA synthesis
-New cell synthesis
-cell division
-accepts single carbon compounds to help form DNA and metabolize amino acids
-contributes to the formation of neurotransmitters
- may help to improve depression
Folate B-9 (recommendations)
RDA: 400 mcg
DV: 400 mcg
UL: 1000 mcg (synthetic only)
Folate B-9 (deficiency)
-macrocytic anemia
-macrocytic blood cells are unable to divide, large in size (megaloblasts)
-causes spina bifida (in babies spine protrudes out)
-milk fortification has decreased rates of spina bifida
-causes neural tube defects
-woman who may become pregnant are recommended to take 100% RDA suppleents 600 mcg (avg woman= 230 mcg/day)
vitamin B-12 (main functions)
-folate metabolism
-red blood formation
-enables conversion of folate coenzymes needed for metabolic reactions, such as DNA synthesis
-maintains the myelin sheath that insulates neurons
B-12 is synthesized by bacteria, and fungi then incorporated into animal tissues when animals consume them.
-intrinsic factor, produced in the stomach, is required for B-12 absorption
-3-5 year storage in liver
Vitamin B-12 (recommendations)
RDA: 2.4 mcg
DV: 2.4 mcg
UL: none
B-12 (path in body)
mouth: salivary glands produce R-protein
stomach: HCl and pepsin release B-12 from food protein. the free vitamin B-12 binds to R-protein. Parietal cells of the stomach secrete intrinsic factor
Liver/gallbladder: some vitamin b-12 stored in liver
pancreas: secretes trypsin into the small intestine: trypsin releases vitamin b-12 from the r-protein. the free vitamin b-12 links with intrinsic factor. when chyme reaches the illeum, the b-12/intrinsic factor complex is absorbed into the blood and binds with a transport protein
Vitamin B-12 deficieny
-leads to pernicious anemia
-nerve damage
-could create a folate deficiency which would lead to anemia
-folate supplements would mask a B12 deficiency
-elderly may have lower stomach acid which could lower B12 absorption
which vitamins recycle homocystine?
Vitamins B-6, B-12, B-9
what is homocystine?
-byproduct of protein digestion
-high levels of homocystine have been linked to the artery clogging process in heart disease (atherosclerosis)
-B6, 12, and 9 help turn homocystine into less damaging substance
-diets low in B6, 12, and 9 lead to higher homocystine levels -> increased risk of heart disease and stroke
Vitamin C ascorbic acid (main functions)
-assists in formation of connective tissue, bones, teeth, tendons and blood vessels
-serves as an antioxidant through acceptance and donation of electrons
-enhances the absorption of iron
-required for proper immuune function
-wound healing
Vitamin C ascorbic acid (recommendations)
RDA Men: 90 mg
RDA women: 75 mg
DV: 90 mg
UL: 2000 mg
Vitamin C ascorbic acid (food groups):
bright fruits and veg, fortified cereals, cottage cheese
Vitamin C ascorbic acid (deficiency)
-scurvy
-skin and blood vessels weaken and wounds do not heal
-bleeding gums, tooth loss, scaly skin, bruising
-only 10mg/day needed to prevent scurvy
Vitamin C ascorbic acid (toxicity)
-diarrhea, nausea, abdominal cramps
-kidney stones
-suppresses immune function
-pro-oxidative in large doses
-UL 2000 mg
Red Veg/fruits
phytochemical: lycopene
veg/fruit: tomato, prink grapefruit, watermelon
red and purple veg/fruit
phytochemical: anthocyanins, polyphenols
veg/fruit: berries, grapes, red wine, prunes
orange veg/fruits
phytochemical: alpha, beta-carotene
veg/fruit: carrots, magos, pumpkin
orange and yellow veg/fruit
phytochemical: beta-cryptoxanthin, flavanoids
veg/fruit: cantaloupe, peaches, oranges, papaya, nectarines
yellow and green fruit/veg
phytochemicals: lutein, zeaxanthin
fruit veg: spinach, avacado, honeydew, collard, turnip greens
green fruit/veg
phytochemical: sulforaphanes, indoles, isothiocyanates
fruit/veg: cabbage, broccoli, brussel sprouts, cauliflower
white/green fruit/veg
phytochemicals: allyl sulphides
fruit/veg: leeks, onion, garlic, chives
functions of phytochemicals:
-support the immune system
-reduce inflammation and blood pressure
-prevent DNA damage/aid in repair
-reduce oxidative damage to cells
-promote cardiovascular, neurocognitive, eye, and bone care
-regulate intracellular signaling of hormone and gene expression
- activate insulin receptors
-inhibit the initiation of and proliferation of cancer, and stimulate spontaneous cell death
-alter the absorption, production, and metabolism of cholesterol
-mimic hormones and enzymes
-decrease the formation of blood clots
catechins
tea
phyosterols
soybeans, legumes, cucumbers,
isoflavones
soybeans, legumes
monoterpenes
oranges, lemons, grapefruit
fructooligosaccharides
onions, bananas, oranges
resveratrol
grapes, peanuts, red wine
saponins
garlic, onion, licorice, legumes
lignans
flaxseed, berries, whole grain
capsaicin
chilli peppers
what causes loss of vitamins?
-cooking
-heat
-air
-light
-acidity
-storage time
-freezing (not much lost)
-depleted soil
tips for preserving fruits/veg
-cool until eaten
-refridgerate
-wait to trim/peel/cut
-minimal contact with water (microwave, steam, stir fry)
-
vitamin c loss in green beans
fresh: 58% lost in 3 days
frozen: 15-20% lost
canned: 15-20%
which ppl are most likely to have nutrient gap?
-elevated nutrient needs (due to malabsorption, aging, chronic disease, medications, growth, pregnancy, lactation)
-limited ability to consume food (poor apetite, calorie restriction)
why choose food over supplements?
-over 25,000 bioactive compounds in foods
-supplement do not reduce risk disease that eating variety of foods does
what is cancer?
-genetic disease
-abnormal cell growth (may become tumor)
-
cancer progression
Initiation
* Normal cells are altered and damaged by an initiator
Promotion (promoters increase cell growth → tumor )
* Some genes that regulate cell division can be mutated and thereby
activated
Oncogenes turned on (mutate from proto-oncogenes: genes that promote cell
division)
Tumor suppressor genes turned off: Genes that slow down cell division
Carcinogen - cancer causing agent
* Radiation
* Chemicals
* Viruses
* Genetics
* Diet
* UV-rays
Hyperplasia
cells within tissue
multiply faster than normal but
still look normal
Dysplasia
cells multiply faster
than normal and they look
abnormal and are disorganized
In situ
“in it’s place” Neoplastic
cells have not invaded surrounding
tissue. Considered a precursor to
cancer, not a malignancy
Metastasis
growth of malignant
tissue becomes invasive and
spreads to surrounding tissue
Diet, Nutrition, Physical Activity and Cancer: A
Global Perspective, 3rd Expert Report, 2018
-Be a healthy weight
Be physically active
Limit alcohol consumption
Eat whole grains, vegetables,
fruits, and beans
Limit fast foods
Limit red/processed meats
Limit SSB
Don’t rely on supplements
Breastfeed your baby, if you
can
https://www.wcrf.org/dietandcancer
World Cancer Research Fund/American Institute of Cancer Research. Diet, Nutrition, Physical Activity and Cancer: A Global Per spective.
Continuous Update Project Expert Report, 2018. www.dietandcancerreport.org
