NTR ch.10

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