Antioxidants (slide 37-80) Flashcards
Why do antioxidants donate electrons? (3)
To neutralize free radicals
Prevent & counteract oxidative reactions
Regenerate other antioxidants
What are free radicals?
Unstable and highly reactive molecules
Free radicals are also produced from: (5)
UV light
Alcohol
Smoking
High fat diets
Over supplementation
When does oxidative stress happens?
Free radicals»_space; antioxidant defense
Excess oxidative stress causes damage to cells, tissues, and organs and lead to (2)
inflammation
increase risk for diabetes
With exercise, effect on body’s natural defense
↑ antioxidant enzyme activity
↑ DNA repair
↑ mitochondria
↑ inflammation and programmed cell death
2 types of vitamin A
1) Retinoids
2) Carotenoids
what are retinoids
preformed vitamin A
Growth and development
Active form of vitamin A in animals
Retinoids
what are carotenoids
pigments found in fruits & veg
Vitamin A precursor (orange)
Beta-carotene
Food source of vitamin A (carotenoid)
Dark, colored fruits and veggies
- carrots
- sweet potatoes
- mango
- oranges
Name of vitamin C
Ascorbic acid
Antioxidant functions (2) of vitamin C
Active in extra-cellular tissues
Regenerates vitamin E
Other main functions of vitamin C (3)
Promotes collagen formation and tissue healing
Hormone synthesis
Iron absorption
vitamin C and colds supplementation does not prevent colds but does what?
may reduce duration of illness
Food sources of Vitamin C
Bell peppers
Citrus fruit
Strawberries
Cabbage
Broccoli
Tomatoes
Potatoes
Vitamin C deficiency - name and symptoms
Scurcy
- weakness
- gum disease
- spontaneous bleeding
- sore arms and legs
- poor wound healing
- emotional/personality changes
Toxicity Vitamin C
Diarrhea
Kidney stones
Iron overload
Name of vitamin E
Tocopherols
Main function of Vitamin E
Prevent oxidative damage to lipids
Food source of vitamin E
Vegetable oils
Nuts
Seeds
Whole grains
Avocado
Kiwi
Antioxidant and aerobic exercise (2)
↑ free radical production
↑ defense against free radicals
Athletes at higher risk of oxidative stress: (2 profiles)
Endurance and ultra-endurance athletes
Low fruit & vegetable intake
Supplementation of antioxidants in athletes - recommendations and why
Not recommended
Impair athletic performance
Interfere with normal positive adaptive responses
Exception to supplementation of antioxidants for athletes
Vitamin E for training in high altitudes
Recommendation to obtain sufficient antioxidants via diet (3)
Colorful fruits and vegetables
Whole grains
Nuts
What is erythropoiesis?
Formation of red blood cells
Water soluble vitamin that is stored in the liver
Cobalamin
Main function of B12 (3)
FA oxidation
Maintaining myelin sheath
Role in DNA synthesis with folate
What is required for B12 absorption?
Intrinsic factor (IF)
Characteristics of intrinsic factor (B12)
Produced in the stomach
Activated by acid
Binds B12 in small intestine
Who is at risk for vitamin B12 deficiency from impaired absorption?
- Chronic diarrhea
- Sloughing of the brush border due to age, illness or medication
- Elderly individuals (produce less IF)
Who is at risk for vitamin B12 deficiency from decreased intake?
Vegetarian or vegan diet
B12 food sources
ONLY in animal foods
Fish
Shellfish
Liver
Beef
Poultry
Milk and dairy
Eggs
Other sources of B12
Breakfast cereals
Plant-based milks
Nutritional yeasts
Fermented soy products
Algae/seaweed
B12 deficiency (2 consequences)
1) neurological symptoms
2) megaloblastic anemia
Toxicity from B12
None
Folate is ____ less bioavailable vs folic acid
50%
Terminology - folate vs folic acid
Folate: naturally occurring (dietary)
Folic acid: fortified foods or supplements (synthetic)
Name of B9
Folate
Main function of folate (B9)
Critical for DNA synthesis and cell division
Food sources of folate
Fortified flours & whole grain products
Green leafy vegetables
Liver
Legumes
Oranges
Nuts
Folate deficiency (2 types)
1) Neural tube defects
2) Megaloblastic anemia
Toxicity from folate (B9)
None
What is anemia
Low RBC count
Vitamin-deficiencies type of anemia (2)
megaloblastic
macrocytic
Mineral-deficiencies anemia
Microcytic
Chronic disease anemia
Normocytic
Symptoms of anemia
Fatigue
Pale skin
Cold hand/feet
Brittle hair or nails
Shortness of breath
Chest pain
Folate, B12 and athletes
B12 injections not recommended
Folate supplementation not likely to improve performance
Athletes at risk of deficiency of B12
Vegans and vegetarians
Athletes at risk of deficiency of folate
Caloric restriction
Name of vitamin K
Quinones
Main function of Vitamin K
'’Koagulation and klotting’’
Sources of vitamin K
Green fruits and vegetables
Produced by intestinal bacteria
Deficiency of Vitamin K
Bleeding, bruising, fracture risk
Toxicity of vitamin K
clotting, thick blood
For growth and development, which two vitamins function as hormones
Vitamin A and D
Name of vitamin D
calcitriol
Sources of vitamin D
Food sources
UV light exposure
Supplementaion
Major functions (2) of vitamin D
Regulates blood calcium (bone health)
Regulates cardiac and skeletal muscles cells and cellular growth in normal and cancer cells
Factors that affect conversion from UV to vitamin D (7)
Latitude (less in North)
Season of the year (summer more)
Time of the day (10-3pm)
Exposure (clothes, time)
Use of sunscreen (90%)
Skin color (decrease if darker)
Age (decrease if older)
Vitamin D food sources
Fatty fish
Milk and dairy
Egg yolks
Liver
Fortified foods
- orange juice
- plant-based milks
Deficiency of vitamin D - name and symptoms
Rickets (children)
- bowed legs and bone deformation
- stunted growth
- softening of bones and teeth
- osteopenia/osteoporosis *adults
Toxicity of vitamin D
Hypercalcemia
Calcification of soft tissues
Potentially fatal
What is the status of our north american consumption of vitamin D
Low vitamin D - increase risk of diseases
Vitamin D supplementation recommended for most adults
Vitamin D and athletes - recommendation
Increase performance - optimal
Supplementation important if deficient
Athletes at risk of vitamin D deficiency (3)
- indoor training
- vegan diets
- northern hemispheres + dark skin
Vitamin A deficiency - symptom
Night blindness
