Oxidation and Vitamin C

Question 1

What can be Oxidized?

Answer 1

• Cell membrane phospholipids

Low density lipoproteins

Question 2

Oxidative Stress and Disease

Answer 2

• More oxidation increases the risk for:
  
  • Cancer
  • Heart disease

Question 3

Antioxidants Help

Answer 3

• Chemicals that decrease the adverse effects of free radicals by:
  
  • Donating their electrons (without creating more free radicals)
  • Activating enzymes that turn free radicals into less harmful substances

Question 4

What does Vitamin C do?

Answer 4

• Vitamin C is the major water soluble antioxidant

- It is water soluble so it mostly works in the extracellular fluid

Question 5

Vitamin C Food Sources

Answer 5

• Citrus fruits
  
  • Strawberries
  • Kiwi
  • Broccoli
  • Peppers
  • Potatoes

Question 6

Preparation of Vitamin C Food Matters

Answer 6

• Heat and oxygen can destroy vitamin C
  
  • Cooking methods:
  • Microwaving may destroy vitamin C

Question 7

Scurvy

Answer 7

• Can occur about 1 month with little or no vitamin C

- Bleeding gums, loose teeth, hemorrhaging, impaired wound healing, swelling, bone pain, diarrhea

Question 8

Too Much Vitamin C

Answer 8

• Hard to eat toxic amounts but…

- Extra is secreted in the urine

Question 9

Water Soluble vs Fat Soluble Vitamins

Answer 9

• Water soluble vitamins:
  
  • Vitamin C and vitamin B
  • Not stored in the body
  • Fat soluble vitamins:
  • Vitamins A, E, D and K
  • Stored in fat cells

Question 10

What is Vitamin A?

Answer 10

• Absorbed in micelles with Fat

- Stored in the liver and in fat cells

Question 11

What is Beta-Carotene?

Answer 11

• Yellow-orange pigment

- Is a pro-vitamin

Question 12

What does Vitamin A do?

Answer 12

• Needed for cell differentiation
  
  • Example: stem cells can become any type of cell
  • Needed for the immune system:
  • To make healthy skin cells, healthy cell membranes that will keep out infections
  • Needed for the differentiation of immune cells (T-cells)
  • Needed for Reproduction:
  • For the production of sperm
  • For fertilization to happen

Question 13

What does Beta-Carotene do?

Answer 13

• Beta-carotene is an antioxidant

Question 14

How much Beta-Carotene do you need?

Answer 14

• In Canada, half of our dietary vitamin A comes from the preformed vitamin A
  
  • The other half comes from beta-carotene

Question 15

Sources of Pre-formed Vitamin A

Answer 15

• Milk
  
  • Eggs
  • Cheese
  • Butter

Question 16

Sources of Beta-Carotene

Answer 16

• Broccoli
  
  • Cantaloupe
  • Carrots
  • Squash
  • Peppers
  • Leafy greens

Question 17

Lack of Vitamin A

Answer 17

• Xeropthalmia - dry eyes

- Immune compromises

Question 18

What if you Eat too much Vitamin A?

Answer 18

• Liver and organ damage
  
  • Birth defects in pregnant women
  • Its possible to overdose from food sources alone
  • UL is 2000 RAE (just over twice the RDA)