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Unit XI: Fat Soluble Vitamins

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Title: Unit XI: Fat Soluble Vitamins Author: Sherry Fuller-Espie Last modified by: ofaoye Created Date: 2/17/2003 9:58:33 PM Document presentation format – PowerPoint PPT presentation

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Title: Unit XI: Fat Soluble Vitamins


1

Chapter 11 Fat Soluble Vitamins ADEK
2
Chapter 11 - FSV
  • Characteristics of fat-soluble vitamins
  • Do not dissolve in water, but dissolve in fat or
    organic solvents.
  • Dietary fat soluble vitamins need bile for
    absorption.
  • The fat-soluble vitamins include vitamins A, D,E
    and K
  • Found in the fats and oils of foods.
  • Stored in the liver and fat tissue until needed
  • not readily excreted from the body.
  • Risk of toxicity.

3
Storage of vitamins in the body
  • Vitamins A, D and E
  • These three fat-soluble vitamins can accumulate
    in the liver and fat tissue of the body and are
    not readily excreted. Long-term intakes more
    than the RDA can be toxic, particularly vitamins
    A and D.
  • Vitamin K
  • The other fat-soluble vitamin, vitamin K, is
    readily excreted from the body.

4
Absorption transport
  • The fat-soluble vitamins, like lipids are
    absorbed with dietary fat.
  • Bile aids in the absorption of fat-soluble
    vitamins.
  • The GI must function adequately for efficient
    uptake of fat-soluble vitamins.
  • Under normal conditions, healthy individuals will
    absorb 40-90 of fat-soluble vitamins.

5
Absorption Transport
  • Fat malabsorption interfere with the absorption
    of FSV.
  • Unabsorbed fat is excreted as feces.
  • The following conditions adversely affect the
    uptake of fat-soluble vitamins
  • Cystic fibrosis
  • Crohns disease
  • Celiac disease
  • Certain medications

6

Vitamin A
  • Family of compounds called Retinoids
  • Retinol supports reproductive functions
  • Found in animal foods and nutrient supplements.
  • Can converted to retinoic acid and retinal in the
    body.
  • Retinal Aid in vision
  • Retinoic acid regulates growth
  • 90 of retinoids are absorbed
  • These are preformed Vitamin A form that the
    body readily uses. Found only in animal sources

7
Provitamin A carotenoids
  • Found in plant sources
  • Not biologically available until they are changed
    into one of the retinoids in the body
  • There are over 600 different carotenoids only 3
    can be converted to vitamin A
  • Beta carotene (most common form)
  • Alpha carotene
  • Beta- cryptoxanthin
  • Accounts for 25 35 percent of dietary vitamin A
    consumed in the US

8
Functions of Vit A
  • Essential for healthy eyes
  • Promotes cell differentiation
  • Determines what cell becomes in your body
  • Supports reproductive system, development of
    limbs, heart eyes and ears
  • Promotes bone and teeth growth
  • Play a role in immunity and preventing infections
    by creating white blood cells
  • Carotenoids, which act as antioxidants, decrease
    the damaging effects of free radicals.

9
Sources of Vitamin A
  • Sources
  • Preformed Vit A
  • Organ meats (liver), milk, cereals, cheese and
    eggs are the most popular sources of
  • Provitamin A (carotenoids)
  • Fruits peaches, apricots, cantaloupes, mangoes,
    papaya
  • Vegetables tomatoes, carrots, winter squash,
    sweet potatoes, broccoli, romaine lettuce,
    collard greens and spinach.
  • Adding as little as 1 tablespoon of vegetable oil
    to your diet can increase absorption of
    carotenoids by as much as 25

10
Vitamin A
  • RDA can be measured in micrograms of retinoic
    activity equivalents (RAE) or in international
    units (IU). 1 RAE 3.3 IU
  • 900 microgram for men
  • 700 microgram for women
  • Upper limit 3,000 microgram/day
  • Deficiency
  • Night blindness difficulty seeing at dusk,
    cant adjust from day light to dark
  • Vitamin A deficiency is the main cause of
    non-accidental blindness (Xerophthalmia)
  • Many die after blindness as a result of
    infection.
  • The eye becomes prone to infections when the
    conjunctiva is damaged.
  • Infections can spread systemically throughout the
    body.

11

12
Toxicity
  • Hypervitaminosis A - is a condition that results
    from excessive intake of vitamin A from
    supplements
  • Cause defective physical development during early
    development of the fetus resulting in birth
    defects
  • Even 3X RDA vitamin A is considered risky during
    pregnancy.
  • Accutane is associated with congenital
    malformations result involving the head and
    brain.
  • FDA has recommended that women of childbearing
    years limit their vitamin A intake to 100 RDA

13
Toxicity
  • High consumption of vitamin A has been linked to
    osteoporosis and increased risk of fractures
  • Provitamin A carotenoids in foods are not toxic
  • Extra carotenoids are stored in the liver and in
    the fat under the skin, causing carotenodermia

14

Fig. 11-7, p. 375
15
Vitamin D/calceferol
  • Also called the sunshine vitamin because it is
    made with the help of ultraviolet (UV) rays from
    sunlight
  • Vitamin D enters your body in an inactive form
  • The kidneys convert dietary vitamin D into the
    active form
  • Precursor bodys cholesterol

16
Vitamin D/ calceferol
  • Functions of Vit D
  • Helps bone health by regulating calcium and
    phosphorus concentration in the blood
  • When blood concentration of calcium is low,
    vitamin D and parathyroid hormone signals the
    kidney to decrease excretion of calcium and
    phosphorous
  • Sources of vit D
  • Fortified milk, cereals, yogurt, fatty fish

17
Vitamin D
  • Adequate Intake
  • 5 micrograms/day for 19-50 yr
  • 10 micrograms/day for 51-70 yr
  • 15 micrograms/day for gt70 yr
  • Upper level 50 micrograms/day

18
Vitamin D
  • Deficiency
  • Rickets in children (soft bones)
  • poor bone mineralization
  • Bowed legs
  • Unable to hold up their own weight when standing
    up
  • Recently researchers have found a rise in rickets
    among children,
  • linked to increase consumption of soft drinks
  • Limited outdoor activities
  • Fear of skin cancer
  • Air pollution reduces ultraviolet rays of the sun
    by as much as 60

19
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20
Vitamin D
  • Osteomalacia - adult form of rickets
  • Occurs in women with decreased calcium and
    phosphorus intake
  • Causes bone weakness and pain
  • Can lead to osteoporosis

21
Vitamin D Toxicity
  • Hypervitaminosis D associated with
    over-consumption of supplements
  • Increased calcium withdrawal in bones and
    intestines
  • Increased calcium and phosphorous
  • concentrations in the blood (hypercalcemia)
  • Increase calcium deposits in kidneys, lungs,
    blood vessels and heart

22
Vitamin E
  • Vitamin E is an effective antioxidant
  • Prevent oxidation of lipids, vit A and LDL to
    prevent build-up in the arteries
  • Neutralize free radicals before they damage cell
    membranes
  • Prevents blood clotting in the blood by acting as
    anticoagulant
  • There are 8 different forms, only one is active
    in the body (alpha- tocopherol)
  • The synthetic is only half as active as the
    natural

23
Vitamin E
  • Sources
  • Polyunsaturated plant oils (vegetable oils)
  • Nuts and seeds
  • Leafy green vegetables
  • Fortified cereals
  • RDA
  • Adults need 15 milligrams/day
  • Upper limit is 1,000 milligrams

24
Vitamin E
  • Deficiency
  • Erythrocyte hemolysis in premature infants (red
    blood cell destruction causing anemia)
  • Toxicity from synthetic form or fortified foods
  • increase risk of hemorrhage
  • A deficiency of vitamin K can increase the
    anticoagulant effect

25
Vitamin K
  • There are two forms of vitamin K
  • Menaquinone synthesized by the intestinal tract
  • Phylloquinone found in green plants
  • Functions
  • Essential for blood clotting
  • Vitamin K plays a role synthesizing clotting
    factors
  • Without vit k a simple cut on the finger would
    cause uncontrollable bleeding
  • Synthesis of bone protein (osteocalcin) that
    regulates blood calcium.

26
Vitamin K
  • Inadequate amount of vitamin K may contribute to
    osteoporosis, associated with increased risk of
    hip fractures
  • Sources
  • Intestinal bacteria can make vitamin K but not
    enough to meet all of the bodys needs
  • Leafy green vegetables
  • Cabbage family vegetables
  • Vegetable oils and margarine

27
Vitamin K
  • Deficiency
  • Newborn infants receive a single dose of vitamin
    K at birth because of a sterile intestinal tract
    to prevent hemorrhagic disease
  • Rare in healthy individuals
  • Toxicity
  • No known adverse effect from consuming too much
    vitamin K from food or supplement
  • Interferes with anticlotting medication (coumadin)

28
Recommendation for Vitamin K
  • Adequate Intake (based on amount that is consumed
    on average)
  • Infants 2 2.5 microgram
  • Children 30 55 microgram
  • Men 60 120 microgram
  • Women 60 90 microgram

29
Homework/extra credit
  • 5 points
  • Complete the vitamin/mineral evaluation form
    posted on the course website
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