• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Chapter 8 Notes
 

Chapter 8 Notes

on

  • 4,886 views

 

Statistics

Views

Total Views
4,886
Views on SlideShare
4,826
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

12 of 2 previous next

  • 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,…)
    • 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
    • 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
    •