Transcript Vitamins: Vital Keys to Health

Vitamins:
Vital Keys to Health
BIOL 103, Chapter 9-2
Today’s Topics
• The Water-Soluble Vitamins: Eight Bs and a C
• Bogus Vitamins
Summary of Fat-Soluble Vitamins
The Water-Soluble Vitamins:
Eight Bs and a C
• Primarily coenzymes
• Antioxidants
• What to keep in mind about each vitamins:
– Function
– Food sources
– Toxicity vs. Deficiency
What is a Coenzyme?
• Coenzyme: a small compound that helps
enzymes in biochemical reactions. Most
coenzymes are derived from vitamins or are
made from vitamins.
Thiamin/B1
• Functions:
– Coenzyme in _______________________________
– Part of the coenzyme: thiamin pyrophosphate (TPP)
• Helps break down glucose, make RNA and DNA, helps power
protein synthesis
• Helps synthesize and regulate neurotransmitters
• Food sources:
– Pork, legumes, nuts and seeds, fish and seafood,
enriched grain product
– Cooking ____________________ content
Thiamin/B1
• Deficiency:
– ________________: overall profound muscle
weakness and nerve destruction
• _____________________________
• Occurs with __________________________ because it
interferes with B vitamin absorption
– Q: Why would Beriberi be more common in Southeast
Asia?
• Toxicity:
– None reported
Riboflavin/B2
• Functions:
1. Coenzyme in __________________________ (extracts
energy from glucose, fatty acids, and amino acids)
2. Supports __________________
• Food sources:
– Milk and dairy products
– Enriched grains, eggs
• Deficiency:
– _________________________________
• Usually occurs with chronic alcoholism
• Toxicity: UL is not set
Niacin/B3
• Functions:
1. Coenzyme in _______________________
2. Supports __________________________
• Food sources:
– Can be made from ____________________
• Need B1, B6, and iron to convert to B3
– Whole and enriched grains
– Meat, poultry, fish, nuts, peanuts
Niacin/B3
• Deficiency:
– ________________: “rough skin”
• Four D’s: _____________________________________
______________________________________________
– Can worsen if also deficient in
________________________________________.
• Toxicity and medicinal uses
– High doses used to treat high blood cholesterol
– Side effects: ______________________________
__________________________________________
Pyridoxine/B6
• Functions:
1. Coenzyme in _________________________ metabolism
2. Supports _______________________
3. Helps to lower blood levels of homocysteine  reduce
risk for heart disease
• Diagram:
• Food sources:
– Meat, fish, poultry, potatoes, bananas, sunflower seeds
Pyridoxine/B6
• Deficiency
– _______________________________________ :
anemia characterized by small, pale red blood
cells that lack adequate hemoglobin to carry
oxygen.
• Can also be caused by deficiency in __________
• Toxicity and medicinal uses
– Can cause ________________________________
– Other symptoms: upset stomach, headaches,
sleepiness, tingling/prickling or burning sensation
Folate/B9
• Functions:
1. Coenzyme in _______________________________
2. Needed for normal ___________________ synthesis
3. Works with ___________________ to help control
homocysteine levels
• Food sources:
– Fortified cereals, enriched grains
– Green, leafy vegetables
• Think of folate like foliage
Folate/B9
• Deficiency:
– _______________________________:
• Not enough folate  red blood cells cannot form DNA and cannot
divide  become large, immature cells  cannot carry oxygen
properly  anemia
– Birth defects in the Neural Tube: ______________________
– Heart disease from elevated homocysteine levels
• Toxicity:
– Can mask ___________________ deficiency when you take
folate supplements
Cobalamin/B12
• “Cobalt-containing compounds” (cobalamin)
• Functions:
1. Needed for normal __________________ functions
•
•
DNA and red blood cell synthesis
Metabolize homocysteine
2. Maintains myelin sheath around nerves  _______
_______________________________
• Food sources:
– Only animal foods: meats, liver, milk, eggs
– Some fortified foods
Cobalamin/B12
• Absorption:
– Requires ____________________ and
___________________________
• Deficiency:
– Can be caused by Pernicious anemia: autoimmune
disorder that damages stomach linings  reduced
B12 absorption
– Nerve damage
• Toxicity:
– No UL set
Figure 9.32: Absorption of B12
Pantothenic Acid/B5
• Function:
1. Component of __________,
which is a part of acetyl CoA
 helps extract energy from
nutrients and help build fatty
acids
• Food sources:
– Widespread in foods
– Reduced by _______________
_________________________
• Deficiency/Toxicity: Rare
Biotin/B7
• Functions:
– Acts as a coenzyme in:
1.
2.
3.
4.
________________________________
________________________________
________________________________
Release of energy from ____________________
• Food sources:
–
–
Cauliflower, liver, peanuts, cheese
Protein avidin (raw egg whites) binds biotin and
prevents absorption
• Deficiency and Toxicity are rare
Vitamin C
• Functions:
– _________________________________
– Needed for ________________________
– Other roles:
• Make other essential compounds (steroid hormones, thyroid
hormones, bile salts, parts of DNA)
• Enhances the absorption of iron from plant foods
• Food sources:
– Fruits: citrus, strawberries, kiwi
– Vegetables: broccoli, tomatoes, leafy green, potatoes
Vitamin C
• Deficiency:
– _____________
• Toxicity:
– May cause ____________________
– For some people: kidney stones, iron toxicity
Choline: A Vitamin-Like Substance
• Function:
– Act as a ___________________ to help
metabolize homocysteine
• Food sources:
– Milk, liver, egg yolk, peanuts; overall is abundant
in food
• Deficiency: Unlikely in healthy people
• Toxicity:
– Diarrhea, falling blood pressure, fishy body odor
Bogus Vitamins
• Bogus vitamins: Unnecessary substances
found in some supplements
– Examples: hesperidin, para-aminobenzoic acid
(PABA), pangamic acid, rutin
– Think twice before you buy them!