vitamins

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					Vitamins
Dietary Supplement Use (USA)
• $ 4,300,000,000 for vit/min in 1995
• $ 1,400,000,000 for herbs
• $ 31,000,000,000 total for dietary
    supplements and functional foods in 1999
    (GAO, 2000)
•   42% adults regular users (27% 1989)
    –   females > males
    –   66% multi-vit/min
    –   37% vitamin C
    –   19% vitamin E
Dietary Supplement Use: Pros
• Supplements prevents dietary
 deficiencies
 – calcium
 – folic acid
• Amounts used in some studies
 not attainable with dietary
 sources
 – antioxidants
Dietary Supplement Use: Cons

• False sense of security
  – folic acid and pregnancy
• Does not contain all potentially
 useful chemicals in foods
  – plant phytochemicals
• Toxicity almost only due to
  supplement use
• Costs significant to low income
Vitamin/Mineral Deficiency
Worldwide
• 1 in 5 adults malnourished
• 1 in 4 children malnourished
• 3 million children severe vitamin
 A deficiency
  –blindness
  –stunted growth
  –275 million with mild deficiency
Vitamins: Definition
• Organic compound found in
  foods
• Required in small amounts
• Required in the diet (essential)
• Proven to be required for
  health, growth, and
  reproduction
Water Soluble Vs. Fat Soluble

• Water Soluble:
  – Vitamin C, and the B vitamins
• Fat Soluble
  – Vitamins A,D,E,K
Vitamins: Support Staff

• What can’t they do?
  – They can’t be used as an energy source.
• What can they do?
  – They are usually in supporting roles in the
    body.
     • e.g.: many of the B vitamins are co-enzymes that
      help breakdown glucose for energy
The differences between water
and fat soluble vitamins
• Absorption from digestive system
  – fat soluble: into the lymph with chylomicrons
  – H20 soluble: into blood
• Transport
  – fat sol: carried by lipoproteins
  – water sol: free in blood
Water Vs Fat Soluble

• Storage and Excretion
  – Fat Sol: stored with fat in cells and adipose
    tissue, excesses stored
  – Water sol: not held firmly by cells, excesses
    excreted
  – Potential for Fat soluble to build up and
    perhaps reach toxic levels
  – Potential for water soluble to excrete extra
    amounts, not as prone to toxicity
Fat soluble Toxicity

• Fat soluble vitamins may be toxic with too
  high of an intake
• Water soluble vitamins are less likely to be
  toxic with high intake
B Vitamins

• Correct names and common names
• Thiamin                B1
• Riboflavin       B2
• Niacin           nicotinic acid
• B6               pyridoxine
• folacin          folate, folic acid
• B12              cobalamin
B vitamins: Correct names

• pantothenic acid         no other
• biotin                   no other

• B vitamins act as coenzymes
  – Help to complete the correct shape of the
    molecule
  – Many help to metabolize glucose to release
    energy
B Vitamins

• Coenzyme function
  – Prosthetic Group: physically become part of
    an enzyme complex
  – Others are more loosely attached
  – May be part of the active site in the enzyme.
Vitamins and Metabolism
B Vitamins

• Thiamin
• Riboflavin
• Vitamin B 6 (pyridoxine)
• Folate
B vitamin deficiencies
• Thiamin: beriberi
  – symptoms: mental confusion, muscle weakness and
    wasting, edema, enlarged heart
• Riboflavin:
  – symptoms: personality changes, cracks at the corners
    of your mouth(cheilosis), tender tongue(glossitis)
• Folacin:
  – Symptoms: megaloblastic, macrocytic anemia,
Niacin
• Part of NAD+
  – helps metabolize glucose
  – without Niacin, this breakdown of glucose stops
  – Slows energy release: 4 D’s of Niacin deficiency
    (called pellagra:
     • Dermatitis: skin inflammation
     • Diarrhea: poor absorption
     • Dementia: no energy to think
     • Death: if untreated
Pellagra
Vitamin B 12

• Blood formation
• Homocysteine
• Nerve damage
• Deficiency
 –Atrophic gastritis
 –Pernicious anemia
Megaloblastic anemia
Vascular Disease
• Folate and vitamin B12 are required for the
  breakdown of the amino acid homocysteine.

• Low folate and vitamin B12 intake may cause
  an increased level of homocysteine.

• High homocysteine levels are associated with
  greater risk of cardivascular and
  cerebrovascular disease.
B vitamin Toxicities: Rare
• B6
  – Symptoms: with very high doses sensory nerve
    disorders; may interfere with nerve impulses and
    heart beat
• Niacin
  – Symptoms: skin flushing, nausea, jaundice, liver
    dysfunction
     • Some individuals with high serum cholesterol are treated
       with pharmacological doses of niacin
Oxidation
• Oxidation: the loss of electrons from a
  molecule.

• Reduction: the gain of electrons by a
  molecule.

• Oxidation and reduction usually occur
  together as an exchange reaction.
Oxidation
•Stable atoms contain an even number of
paired electrons.

•Free radical: an atom that has lost an
electron and is left with an unpaired
electron.

•Free radicals are highly reactive and can
cause damage to molecules in the cell.
Free Radicals and Diseases
Antioxidants
• Substances that are able to neutralize
  reactive molecules and reduce oxidative
  damage
• Result of metabolic processes and
  environmental sources
• Vitamin C, Vitamin E, beta-carotene,
  Vitamin A, selenium, iron, zinc, copper
  and manganese
Vitamin C Functions

• Collagen Formation
• antioxidant
  – reduce cancer risk
  – helps absorb iron from food
  – Reduces risk of colds?????
     • probably not
     • Linus Pauling’s study
     • NutraIngredients
Vitamin C
• Deficiency: called scurvy
   – poor formation of collagen in blood vessels
      • weak vessels result in hemorrhages
      • can be severe and result in lots of blood loss and death
• Toxicity: may result in
   –   kidney stones
   –   rebound scurvy
   –   Destruction of B12
   –   Problems with acid/base balance
Vitamin C: RDA 90/75 mg/day
• Foods rich in vitamin C:
   – 1 cup fresh squeezed orange juice: 124 mg
   – 1 cup canned o.j.: 84 mg
• Smoker’s RDA = +35 mg/day
   – Some of vitamin C is sacrificed in reducing
     the oxidants of cigarette smoke
• Vitamin C intake offers protection against
  stomach cancer
Vitamin C

• Deficiency: called scurvy
  – poor formation of collagen in blood vessels
     • weak vessels result in hemorrhages
     • can be severe and result in lots of blood loss
      and death
• Toxicity: may result in
  – kidney stones
  – rebound scurvy
  – Destruction of B12
Vitamin C: RDA 60 mg/day

• Foods rich in vitamin C:
  – 1 cup fresh squeezed orange juice: 124 mg
  – 1 cup canned o.j.: 84 mg
• Smoker’s RDA = 100 mg/day
  – Some of vitamin C is sacrificed in reducing
    the oxidants of cigarette smoke
Vitamin A Functions

• Vision: helps with conversion of light
  energy to electrical energy in eye
• Cell differentiation-maintenance of
  linings:
   – helps produce the CHO normally found in
     mucous
• Bone growth:
   – helps with remodeling growing bones
Vitamin A Deficiency
• One year supply in fat and liver of most people:
  So deficiencies are rare
  – Bone growth and remodeling problems
     • shape changes
  – Linings deteriorate
     • GI tract: diarrhea
     • Respiratory tract: infections
     • urogenital tract: infections, kidney stones
  – Impaired night vision and day vision
Vitamin A Toxicities
• Bones:
   – decalcification, joint pain
• Nervous system
   – loss of appetite, irritability, muscle weakness
• Liver enlargement
   – jaundice
• Blood: RBCs loose hemoglobin
   – Bleeding induced easily
Beta-Carotene-provitamin

• Functions
  – Weak antioxidant
  – Enhance immune system
  – Protect skin and eyes
• Deficiency/toxicity
Beta-Carotene-provitamin

• No RDA
• Sources
Beta carotene and Vitamin A
Vitamin A RDA= 700 RE for
females; 900 RE for males.
• RE= Retinol Equivalent
   – Retinol is the active form of vitamin A
   – Other molecules can be metabolized to make
     Retinol, thus retinol equivalents
      • e.g.: beta carotene can be modified to make retinol
      • beta carotene is found in carrots and other deep orange
         and green vegetables
       • 1 RE= 1 microgram of retinol
       • 1 RE= 3.3 IU retinol
       • 1 RE = 12 micrograms of beta carotene
Vitamin A and Beta Carotene
Rich Foods
• 1 medium carrot = 2025 REs; about 2.5
  times the RDA
• 1 cup butternut squash = 1400 REs
• 1 sweet potato = 2000 REs
• 1/2 cup cooked spinach = 700 REs
• 1 cup cooked broccoli = 250 REs
• 1 cup milk = 140 REs
Vitamin D
Functions: Helps bone grow
• Works in three ways:
  – 1. Increases Calcium Absorption from the
    G.I. tract
  – 2. Helps to withdraw calcium from bone
  – 3. Increases calcium retention in the
    kidney.
Sources of Vitamin D
• Body makes it own:
   –Dehydrocholesterol in the skin
    exposed to sunlight
      • Energy transforms it into a pre-vitamin D
           molecule
         • Body heat provides energy to change
           pre-vitamin D into inactive Vitamin D
Netrition Home Page

         • Inactive Vitamin D activated in two steps
            –First, in the Liver
            –Second in the Kidney
Vitamin D
Sources of Vitamin D
 RDA = 5 ug-15 ug
• In foods:
  – Fortified milk: 2.5 mcg/cup
  – 1 egg = 0.7 mcg
  – 3 oz shrimp = 3 mcg
  – 1 tsp margarine = 0.5 mcg
  – USATODAY.com - How to get vitamin D?
Vitamin D Deficiencies
• In children: Rickets
   – malformed bones, bow legs
• In adults: osteomalaciaVitamin D improves symptoms of knee
  osteoarthritis
• most often occurs in women with low Ca intake,
  repeated pregnancies, low sun-exposure, and
  long breastfeeding with infants
   – loss of Calcium from bone and change of shape
• USATODAY.com - Vitamin D reserach may have
  doctors prescribing sunshine
Vitamin D Toxicity:
• Most potentially toxic of all vitamins!!!!
   – As little as 4 to 5 X RDA can be associated with toxic
     symptoms
      • minor: diarrhea, headache, nausea
      • major: calcium deposits in soft tissues of heart, kidney,
        arteries
   – Major concern: those who take Vitamin D
     supplements
      • If some is good, more is NOT better!!!!!
Sources of Vitamin D: RDA =
5 - 10 micrograms in adults
• In foods:
  – Fortified milk: 2.5 mcg/cup
  – 1 egg = 0.7 mcg
  – 3 oz shrimp = 3 mcg
  – 1 tsp margarine = 0.5 mcg
Vitamin K

• Blood coagulation
  –coenzyme
• Deficiency
• Toxicity
Vitamin E
• Functions: Anti-oxidant
   – Guards against damage to membranes from
     oxidizing compounds
• Deficiency: Rare (premature infants under
  3.5 pounds, people unable to absorb fat
  or metabolize fat properly
   – Suppresses the immune system because
     vitamin E protects White Blood Cells
Vitamin E

• Toxicity: Rare
• Sources: Vegetable oils, nuts
 and green leafy vegetables,
 fortified cereals