Oxidation
Atom LOSES an electron
Reduction
Atom GAINES an electron
Antioxidant
Helps prevent/repair damage caused by oxidation
Free Radical
Highly unstable atom with an unpaired electron in its outermost shell
Fat soluble
Absorbed associated with chylomicron, transport through lymph system to liver, the liver incorporated VDLs and circulate in our body.
-Excess amounts can become toxic
-Mostly from supplements
-Gets dissolved in fat, use during that time and the rest are u
What vitamins are fat soluble?
Vitamin D,A,K,E
Cannot be consumed at a regular basis
Water soluble vitamins
Must be consumed at a regular basis in small doses because it cannot be stored
Excess amounts usually not dangerous, but wasteful.
Hydrophilic
Absorbed in the bloodstream and circulate freely in the blood
Cannot be stored
Antioxidant vitamin
donates their electrons to free radicals to stabilize them
What are the antioxidant vitamins?
Vitamin A,C,E and Selenium
Antioxidant minerals
Cofactors, convert free radicals into less dangerous substances that are excreted by the body
Absorption and transport of fat soluble vitamins
The fat-soluble vitamins are soluble in lipids (fats). These vitamins usually absorbed in chylomicrons that travels through the lymphatic system of the small intestine into the liver, and incorporated VDLs in the liver, and into the general blood circulat
Ways to decrease vitamin content in food
Cook them in lots of water
Use lots of heat
Way to preserve vitamin content in foods
Less exposure to heat
Freeze instead of can left over food
Steam or microwave (instead of boiling)
3 Retinoids
3 active forms of vitamin A
- RETINOL (most important)
- Retinal
- Reinoic acid
Retinol
Alcohol form of vitamin A.
- Transport and storage
Retinal
Aldehyde form of Vitamin A
- Part of visual pigment, rhodopsin
Retinoic acid
Acid for of Vitamin A
- Cell differentiation of skin and lining of the body
- Bone growth
- Embryotic development
- Immunity
Reinoids food sources
LIVER! fish, dairy, butter, eggs
Carotenoid food sources
Dark green, red, orange veggies
- Peppers, squash, carrots, sweet potato, Mango, Kale, Cantaloupe
beta-carotine
a precursor to vitamin A. beta-carotine in foods is converted into retinol in the wall of the small intestine
About 90% of vitamin A we absorb is stored in...
the liver. the rest is stored in adipose tissue, the kidneys, and the lungs.
Healthy vision is related to which vitamin?
Vitamin A!
Functions of vitamin A
Antioxidant, helps vision
Carotenoids
Inactive form of vitamin A
Carotenoid food sources
Dark green veggies, deep red/orange veggies. Carrots, Sweet potato, Spinach, Mango, Cantaloupe, fruits
Vitamin A deficiency
Night blindness!
Later sx include:
Xeropthalmia, Keratomalacia - permanent blindness
Death
Too much vitamin A
Damage to liver,
Hair loss, skin rash, bone abnormalities
Acne medication Accutane:
Reinoic acid- toxic to fetus
The liver contains high amounts of what vitamin?
Vitamin A!
Carrots and cantaloupe contain what vitamin??
Carotenoids that can be converted into Vitamin A!
People who don't get enough sunlight can take what?
Vitamin D
Pregnant women need
Multivitamin/supplement with:
iron, zinc, copper,
vitamin B6, vitamin C, and vitamin D
folic acid, and calcium
Vegans need what supplements?
Vitamin B12, vitamin D,
riboflavin, calcium,
iron, and zinc
Selenium functions
Trace mineral, found in the soil.
- Antioxidant, part of gluthione enzyme that Breaks down peroxides so they can't form free radicals.
- Works with Vitamin E to prevent oxidative damage to lipids and cell membranes
- Production of thyroid hormine
- Mainta
Food sources of Selenium
Pork, seafood, nuts, wheat, rice, organ meats
Selenium deficiency
Associated with heart disorder called Keshan disease
Keshan disease
heart disorder associated with selenium deficiency, occurs in china where soil is depleted of selenium. Can be prevented with supplementation
Vitamin E functions
ANTIOXIDANT.
-Protects PUFA (poly unsaturated fatty acids).
-Lowers risk of heart disease because it protects LDLs from being oxidized.
- Protects membranes of red blood cells, and cells of our lungs
- Helps build/repair muscle
- Helps against bacteria/vi
Vitamin E transport
its fat soluble, so dietary fats carry it from the INTESTINES through the LYMPH system and then to cells. - Incorporated into chylomicrons, transported to liver
Symptoms of Vitamin E deficiency
- Anemia (red blood cell fragility)
- Neuromuscular dysfunction
How are LDLs formed?
After VLDLs release their triglyceride load
Vitamin E storage
90% is stored in adipose tissue, the rest is in cell membranes
The liver stores what?
Vitamins A and D and E
Forms of vitamin E
Tocotrienols and Tocopherols
Which is the most active vitamin E compound?
alpha-Tocopherol
Our need for vitamin E increases when
we eat more oils and foods with PUFAs.
Preventing oxidation in foods does what?
Reduces rancidity and spoilage
Vegetable OILS, nuts, seeds, and avocados are good sources of what?
Vitamin E.
(Oils include sunflower, canola, soybean)
Vit E deficiency
Rare. Sx: anemia, impaired vision, speech and movement.
- Erythrocyte hemolysis can occur.
- Also can be caused by diseases not allowing proper absorption of fat
erythrocyte hemolysis
rupturing of red blood cells, leads to anemia
- occurs in premies
Animal and dairy products are poor sources of what?
vit E!
Vitamin E deficiencies occur when there are problems in what organs?
The gallbladder: delivers bile to intestines and helps digestion of fat.
The pancreas: makes fat-digesting enzymes
The liver
Antioxidant vitamins
A C and E. Reduce damage to blood vessels by: Scavenging free radicals, Reducing low-grade inflammation, Reducing blood coagulation and clot formation
Beta-Carotene
Orange/Yellow orange
- carrots, sweet potatoes
- cantaloupe
Lycopene
Red
- Tomatoes, watermelons
- Grapefruit (red & pink)
Leutine & zeaxanthin
Yellow
- Pineapple
- Corn
Green vegetables like spinach, broccoli and kale are also rich in Carotenoids but the color is masked by
chlorophyll
Role of Vitamin A in vision
Rhodopsin absorbs light and its shapes/color change, generating nerve impulses that travel to the brain and allow us to see different colors and changes in brightness
Phytochemical
Naturally occurring in plants, found in whole grains, fruits, veggies, legumes, nuts, garlic and soy products. may reduce risk of cancer/heart disease
Diseases associated with aging
Macular degeneration and Cataracts
Macular degeneration
Leading cause of blindness, part of retina deteriorated, loss of central vision
Cataract
Damaged portion of eye's lens causing cloudy vision
What prevents skin from UV light damage?
beta-carotene
RAE equivalents
beta caortene = 1 rae = 12 ug
alpha carotene (1 rae = 24 ug)
beta crpyoanthin (1 rae = 24 ug)
retinol = 1 ug = 1ug rae
Primary steps of cancer development
Initiation
Promotion
Progression
Antioxidants reduce cancer risk by
Enhancing immune system
Inhibit cancer cell growth
Prevent oxidative damage to cells