Vitamins Flashcards
What factors affect the bioavailability of vitamins?
Low-fat diet may inhib absorption of fat-soluble vitamin
Carrier proteins may be required
Provitamin forms may be absorbed and require conversion to active form
Interaction with other dietary comp may also affect absorption
Why do smokers experience a vitamin C deficiency?
Vitamin C is an antioxidant
Smokers introduce large amounts of oxidants into body that requires large amounts of vit c to get rid of
What is the difference between food fortification and food enrichment?
Food fortification have nutrients added that are not normally found in that food
Food enrichment have nutrients added back that have been removed in processing
How is the absorption of water-soluble vitamins different from fat-soluble?
Fat-Soluble need to be encased in chylomicrons
Water-soluble are able to go into absorptive cells and get transported to where they are needed
Is it common to have toxic levels of water vitamins? Why or why not?
Less likely to be preset at toxic levels
Excreted when ingested in excess
However this means tissue depletion can occur more readily
In what food sources would you find thiamin?
Grain products
meats
What is the leading cause of thiamin deficiency?
What are its symptoms?
Alcohol abuse leads to Wernicke-Korsakoff syndrome
Lack of energy, weakness and neurological symptoms
What is thiamin required for?
Glucose metabolism
What is the function of riboflavin?
Energy production and cell respiration
Iron mobilization
Conversion of vitamins into active forms
Where do you find riboflavin in diet?
Milk
Meat
Vegetables
Grains
Symptoms of riboflavin deficiency
Poor wound healing
Inflamm of eyes, lips, mouth and tongue
Confusion
Symptoms of niacin deficiency (3Ds)
Dermatitis
dementia
diarrhea
Function of vitamin B6
Metabolism of AA
Hemoglobin synthesis
WBC formation
Production of myelin sheet
Source of vitamin B6 in diet
Brown rice
Meat
Deficiency of vitamin B6 causes
Neurological symptoms due to role in NT synthesis or myelin formation
Anemia
Source of vitamin B12 in diet
Mostly available in animal products
Func of Vitamin B12
Myelin sheath formation
Breakdown of FA
Homocysteine to methionine conversion rxn
Deficiency of vitamin B12
Inc blood levels of homocysteine
Megaloblastic anemia
What is folate needed for?
Required for DNA synthesis
and
metabolism of some AA
Deficiency of folate leads to
Explain why
Megaloblastic anemia
Folate needed for DNA synthesis to tell RBC to divide
Why is excess folate dangerous?
Can mask symptoms of B12 deficiency
Allows conversion of methyl folate to folate without need for B12
Anemia symptoms masked however lack of B12 still interferes with myelin sheath synth
What is the func of vitamin C
Coenzyme for synth of bile acids,
NT,
hormones
FA metabolism
Neutralization of oxygen free radicals
Where is vitamin C found in diet
Fresh fruits and vegetables
Good sources like broccoli and strawberries
Why is it easy to get toxic levels of fat-soluble vitamins?
Stored in fat
Leads to higher danger of it building up
Function of vitamin A
Needed for cell differentiation (Mucus secreting cells in eyes replaced by keratin-producing cells)
Retinal for light-sensing in eye
Deficiency symptoms of Vitamin A
Blindness
Decreased immune func
Sources of vitamin A in diet
Beef liver
Orange and yellow vegetables
Eggs
Function of Vitamin D
Maintain calcium and phosphorous levels in blood
Inc expression of calcium transport proteins
Deficiency of vitamin D
Rickets in children
Osteomalacia in adults
Sources of vitamin D in diet
Eggs
Salmon
Milk
What is the function of vitamin E?
Scavenges free radicals
Protects proteins and DNA
Sources of vitamin E in diet
Sunflower seeds Almonds Nuts Oil Eggs Salmon Fruits and vegetables
Function of vitamin K
Necessary to enable blood clots to form
Bone mineralization
Sources of vitamin K in diet
Fruits and vegetables
What are the signs of vitamins A, D, and K toxicities
A: Weight loss, muscle and joint pain, liver damage and birth defects (Give pregnant women carotenoids)
D: Calcium deposition in blood vessels and kidney
K: No known toxic effects, may interfere with anticoagulant drugs
