• Save
Chapter 8 Notes
Upcoming SlideShare
Loading in...5
×
 

Chapter 8 Notes

on

  • 5,347 views

 

Statistics

Views

Total Views
5,347
Views on SlideShare
5,287
Embed Views
60

Actions

Likes
11
Downloads
0
Comments
2

1 Embed 60

http://www.pisgahscience.com 60

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Chapter 8 Notes Chapter 8 Notes Presentation Transcript

  • Chapter 8 Lecture Outline Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display
  • Vitamins
    • Essential organic substances
    • Produce deficiency symptoms when missing from diet
    • Yield no energy
    • Basic functions
      • Facilitate energy-yielding chemical reactions
      • Function as co-enzymes
    • Fat-soluble vitamins
    • Water-soluble vitamins
  • Fun Facts
    • Vitamins were named in order of discovery (A, B, C, D, …)
    • Other substances found not to be essential were dropped (e.g., vitamin P)
    • B-vitamins were thought to be one vitamin; turned out to be many (e.g., B1, B2, B3,…)
    View slide
  • Vital Dietary Components
    • Megadose (>3-10x needs as a starting point)
      • Proved useful in treating certain conditions
    • Plant and animal foods provide vitamins
    • Most synthesized vitamins work equally well in the body
    • Scientists believe they have discovered all the vitamins
    View slide
  • Storage of Vitamins in the Body
    • Fat-soluble
      • Not readily excreted (except vitamin K)
    • Water-soluble
      • Generally lost from the body (except vitamins B-6 and B-12)
      • Excreted via urine
    • Vitamins should be consumed daily
      • Occasional lapse is harmless
  • Vitamin Toxicity
    • Fat-soluble vitamins
      • Can accumulate in the body
    • Water-soluble vitamins
      • Some can cause toxicity
    • Mostly likely due to supplementation
  • Preservation of Vitamins
    • Decreased vitamin content
      • Improper storage
      • Excessive cooking
      • Exposure to light, heat, air, water, and alkalinity
    • Eat foods soon after harvest
    • Freeze foods not consumed within a few days
    • Blanching destroys enzymes
      • Slows down vitamin degradation
  • Preservation Tips
  • Fat-Soluble Vitamins Overview
    • Dissolve in organic solvents
    • Not readily excreted
      • Can cause toxicity
    • Absorbed along with fat
    • Fat malabsorption
      • May cause deficiency
    • Transported with fat
      • In lipoproteins
  • Vitamin A
    • Narrow optimal intake range
    • Preformed
      • Retinoids
      • Found in animal products
    • Proformed
      • Carotenoids
      • Found in plant products
  • Functions of Vitamin A
    • Promote vision
      • Night blindness
    • Promote growth
    • Prevent drying of the skin and eyes
      • Xerophthalmia
    • Promote immune function and resistance to bacterial infection
    • Cardiovascular disease prevention
    • Cancer prevention
    • Acne medication
  • Food Sources of Vitamin A
  • Recommended Amounts for Vitamin A
    • 900  g REA for men
    • 700  g REA for women
    • Daily Value is 1000  g (REA)
    • Upper Level is 3000  g (REA of preformed)
    • Much stored in the liver
    • No separate RDA for carotenoids
  • Toxicity of Vitamin A
    • Large intake of vitamin A (preformed)
      • Over a long period
      • Use of Accutane and Retin-A
    • Signs and symptoms
      • Bone/muscle pain, loss of appetite, skin disorders, headache, dry skin, hair loss, increased liver size, vomiting
      • Fetal malformation
      • Possible permanent damage
    • Effects of high carotenoid intake
  • Vitamin D
    • Prohormone
    • Derived from cholesterol
    • Synthesized from sun exposure
      • Sunscreen SPF > 8 decreases synthesis 95%
      • Expose hands, face, arms 2-3 x/week for 5-10 minutes each time (more for darker skin)
    • Insufficient sun exposure makes this a vitamin
    • Activated by enzymes in liver and kidneys
    • Deficiency can cause disease
  • Activation of Vitamin D
  • Functions of Vitamin D
    • Regulates blood calcium
      • Along with the parathyroid hormone
      • Regulates calcium + phosphorus absorption
      • Reduces kidney excretion of calcium
      • Regulates calcium deposition in bones
    • Influences normal cell development
      • Linked to reduction of breast, colon, and prostate cancer
  • Role in Bone Formation
    • Causes calcium + phosphorus to deposit in the bones
    • Strengthens bones
    • Rickets is the result of low vitamin D
      • Breastfed infants with little sun exposure
    • Osteomalacia (soft bones)
      • Rickets-like disease in adults
      • Bones lose minerals and become porous
  • Food Sources of Vitamin D
    • Fatty fish (salmon, herring)
    • Fortified milk
    • Some fortified cereal
  • Adequate Intake (AI) for Vitamin D
    • 5  g/day (200 IU/day) for adults under age 51
    • 10-15  g/day (400 - 600 IU/day) for older adults
    • Supplement if a breastfed infant
      • (See physician for details)
  • Toxicity Warning
    • Vitamin D can be very toxic, especially in infancy and childhood
    • Upper Level is 50 µ g/day
    • Results in
      • Over-absorption of calcium (hypercalcemia), increase calcium excretion
      • Calcium deposits in organs and blood vessels
      • Growth retardation
  • Vitamin E
    • Fat-soluble antioxidant
    • Resides mostly on cell membranes
  • Other Functions of Vitamin E
    • Protects double bonds in unsaturated fats
    • Improves vitamin A absorption
    • Deficiency
      • Breakdown of cell membranes
      • Hemolysis
      • Nerve degeneration
    • RDA for adults is 15 mg/day
      • Many adults are not meeting this goal
  • Food Sources of Vitamin E
  • Toxicity of Vitamin E
    • Upper Level is 1,000 mg/day (supplementary alpha-tocopherol)
    • Upper Level is 1500 IU (natural sources) or 1100 IU (synthetic forms)
    • Toxic effects
      • Inhibit vitamin K metabolism and anticoagulants
      • Possible hemorrhage
      • Muscle weakness, headaches, nausea
  • Vitamin K (“Koagulation”)
    • Synthesized by bacteria in the colon and absorbed
    • Role in coagulation process
    • Role in calcium-binding potential
  • Food Sources of Vitamin K
    • Liver
    • Green leafy vegetables
    • Broccoli
    • Peas
    • Green beans
    • Resistant to cooking losses
    • Limited vitamin K stored in the body
  • Adequate Intake for Vitamin K
    • 90 µ g/day for women
    • 120 µ g/day for men
    • Excess vitamins A and E
      • Interferes with vitamin K
      • May cause hemorrhage and fractures
    • Newborns
      • Routinely injected with vitamin K
      • Breast milk is a poor source
    • Toxicity unlikely; readily excreted
  • Overview of Water-Soluble Vitamins
    • Dissolve in water
    • Generally readily excreted from body
    • Subject to cooking losses
    • Function as coenzymes
    • Participate in energy metabolism
    • 50-90% of B vitamins are absorbed
    • Marginal deficiency more common
    • Enrichment Act
  • Thiamin
    • Sensitive to alkalinity and heat
    • Coenzyme form used in energy metabolism
    • Deficiency: Beriberi
    • RDA
      • 1.1 mg/day for women
      • 1.2 mg/day for men
      • Most exceed RDA in diet
    • Surplus is rapidly lost in urine; non-toxic
  • Food Sources of Thiamin
  • Riboflavin
    • Coenzyme forms participate in energy-yielding metabolic pathways
    • Deficiency
      • Cheilosis, inflammation of mouth and tongue, dermatitis, sensitivity to sun
    • RDA
      • 1.1 mg/day for women
      • 1.3 mg/day for men
      • Average intake above RDA
    • Non-toxic
  • Food Sources of Riboflavin
    • Milk/milk products
    • Enriched grains/cereals
    • Eggs
    • Liver
    • Spinach
    • Oysters
    • Brewer’s yeast
  • Niacin
    • Coenzyme forms used in energy metabolism
    • Deficiency
      • Pellagra
      • 3 D’s
    • RDA
      • 14 mg/day for women
      • 16 mg/day for men
    • Toxicity
      • Upper Level is 35 mg/day
  • Food Sources of Niacin
    • Enriched grains
    • Beef
    • Chicken/turkey
    • Fish
    • Heat stable; little cooking loss
    • 60 mg tryptophan can be converted into 1 mg niacin
  • Pantothenic Acid
    • Part of Coenzyme-A
      • Essential for metabolism of carbohydrate, fat, and protein
    • Deficiency rare
      • Usually in combination with other deficiencies
  • Food Sources of Pantothenic Acid
    • Meat
    • Milk
    • Mushrooms
    • Liver
    • Peanuts
    • Adequate Intake = 5 mg/day
    • Average intake meets AI
  • Biotin
    • Free and bound form
    • Co-enzyme
      • Metabolism of carbohydrate and fat
      • Helps breakdown certain amino acids
    • Deficiency – rare
      • Scaly, inflamed skin
      • Changes in tongue, lips
      • Decreased appetite, nausea, vomiting
  • Food Sources of Biotin
    • Cauliflower, egg yolk, liver, peanuts, cheese
    • Intestinal synthesis of biotin contributes very little
    • Avidin inhibits absorption
      • More than a dozen raw egg whites a day to cause this effect
  • Biotin Needs
    • Adequate intake is 30 µ g/day for adults
    • No Upper Level for biotin
    • Relatively nontoxic
  • Vitamin B-6
    • Coenzyme forms
      • Activate enzymes needed for metabolism of carbohydrate, fat, and protein
      • Synthesize nonessential amino acids via transamination
      • Synthesize neurotransmitters
      • Synthesize hemoglobin and WBC
      • Role in homocysteine metabolism
  • Food Sources of Vitamin B-6
  • RDA for Vitamin B-6
    • 1.3 mg/day for adults
    • 1.7 mg/day for men over 50
    • 1.5 mg/day for women over 50
    • Daily Value set at 2 mg
    • Average intake is more than RDA
    • Athletes may need more
    • Alcohol increases vitamin B-6 destruction
  • Vitamin B-6 As a Medicine?
    • 50-100 mg/day therapy
      • Questionable treatment of PMS
      • May treat pregnancy hypertension
    • Carpal tunnel syndrome
    • Morning sickness
      • (100 mg/day may help; see Ch. 13)
    • Toxicity potential
      • > 200 mg/day can lead to irreversible nerve damage
    • Upper Level set at 100 mg/day
  • Folate
    • Coenzyme
      • DNA synthesis
      • Homocysteine metabolism
      • Neurotransmitter formation
    • Sensitive to:
      • Heat, oxidation, ultraviolet light
  • Folate Deficiency
    • Megaloblast cells
    • Megaloblastic Anemia
    • Neural tube defects
  •  
  •  
  • Food Sources of Folate
    • Liver
    • Fortified breakfast cereals
    • Grains, legumes
    • Foliage vegetables
    • Orange juice
  • RDA for Folate
    • 400 µ g/day for adults
    • 600 µ g/day for pregnant women
    • Excess intake can mask vitamin B-12 deficiency
    • Upper Level 1 mg (synthetic form)
      • Folate in food has limited absorption
  • Vitamin B-12
    • Synthesized by bacteria and fungi
    • Coenzyme
      • Role in folate metabolism
      • Maintenance of the myelin sheaths
      • RBC formation
    • Deficiency
      • Pernicious anemia
      • Nerve degeneration and paralysis
  • B-12 Absorption
    • Requires a protein from salivary gland
    • Requires stomach acid
    • Requires the intrinsic factor
    • Absorbed in the last part of the small intestine
    • About 50% of B-12 is absorbed
  • Therapy for Ineffective Absorption
    • Many factors can disrupt this process
    • Monthly injections of vitamin B-12
    • Vitamin B-12 nasal gel
    • Megadoses of vitamin B-12
      • Allow for passive diffusion
  • Food Sources of Vitamin B-12
    • Synthesized by bacteria, fungi and algae
    • (Stored primarily in the liver of animals)
    • Animal products
    • Organ meat
    • Seafood
    • Eggs
    • Hot dogs
    • Milk
  • RDA for Vitamin B-12
    • 2.4 µ g/day for adults
      • Over age 50 meet needs with a crystalline source
    • Average intake exceeds RDA
    • B-12 stored in the liver
    • Non-toxic
  • Vitamin C
    • Synthesized by most animals
      • Not by humans
    • Decreased absorption with high intakes
    • Excess excreted
      • Diarrhea common
    • Sensitive to
      • Cooking/heat
      • Iron, copper, oxygen
  • Functions of Vitamin C
    • Synthesis of collagen
    • Iron absorption
    • Immune functions
    • Antioxidant?
  • Deficiency of Vitamin C
    • Scurvy
      • Deficient for 20-40 days
      • Fatigue, pinpoint hemorrhages
      • Bleeding gums
      • Weakness
      • Fractures
      • Associated with poverty
  • Food Sources of Vitamin C
    • Citrus fruits
    • Potatoes
    • Green pepper
    • Cauliflower
    • Broccoli
    • Strawberries
    • Romaine lettuce
    • Spinach
  • RDA for Vitamin C
    • 90 mg/day for adult males
    • 75 mg/day for adult females
    • Daily Value is 60 mg
    • +35 mg/day for smokers
    • Average intake 70-100 mg/day
    • Upper Level is 2 g/day
  • Choline
    • Essential nutrient, though not a vitamin
    • All tissues contain choline
    • Precursor for acetylcholine (neurotransmitter)
    • Precursor for phospholipids
    • Some role in homocysteine metabolism
  • Food Sources of Choline
    • Widely distributed in foods
    • Milk
    • Liver
    • Eggs
    • Peanuts
    • Lecithin added to food
    • Deficiency rare
  • Needs for Choline
    • Adequate Intake is 550 mg/day for males
    • Adequate Intake is 425 mg/day for females
    • Average intake is ~700-1000 mg/day
    • High doses
      • Associated with fishy body odor, vomiting, salivation, sweating, hypotension, GI effects
    • Upper Level is 3.5 grams/day
  • Vitamin-like Compounds
    • Choline
    • Carnitine
    • Inositol
    • Taurine
    • Lipoic acid
    • Synthesized in the body at the expense of amino acids and other nutrients
  • Functions in the Body
  • Dietary Supplements
  • Dietary Supplements
    • Vitamins
    • Minerals
    • Herbs
    • Amino Acids
    • A dietary substance to supplement the diet
  •