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CHAPTER 7
VITAMINS
Vitamin:
- is a component of all natural foods
- are organic compounds
- essential for:
 Growth
 Reproduction &
 The maintenances of health
- NON-CALORIC
- Needed in minute quantity
- Lack of it in the diet results in specific deficiency symptoms that are relieved by
its additional to the diet.
Some vitamins occur in food in a form known as “precursor” or “provitamins.”
IMPORTANT
PRECURSORS, PROVITAMINS
Compounds that can be converted into active vitamins, are called provitamins or
precursors
-
The term “Vitamin” was coined in 1912 by Polish Biochemist Casmir Funk.
Originally used word “VITAMINE” to refer to substances that are “AMINE”
and are “VITAL” to life (VITAL-AMINE)
Today we know vitamins are vital for life but they are not all amines so “e” has
been removed
Initially, the vitamins were named alphabetically in approximately in the same
order in which they were identified such as A ,B, C, D and E.
He B-Vitamins were first thought to be one chemical substance
VITAMINS FALLS INTO TWO GROUPS
Vitamins have traditionally been grouped based on their solubility in water or fat
Water soluble vitamins include:
 The B-Vitamins and
 Vitamin C
Fat soluble vitamin include
 Vitamin A
 Vitamin d
 Vitamin E and
 Vitamin K
Solubility determines how they are
- Absorbed
- Transported by the bloodstream
- Stored
- How they are lost from the body
FAT SOLUBLE VITAMINS
- Dissolve in lipids
- Are stored in liver& with other lipids in the body
- Can build up to toxic level
- Absorbed into the lymph & travel in the blood in association with protein carriers
WATER SOLUBLE VITAMINS
- Dissolve in water
- Easily absorbed & excreted
- Not stored extensively in tissues
- Seldom reach toxic levels
VITAMINS IN DIET
- Almost all foods contain some vitamins for example:
o Grains provide thiamin, niacin, riboflavin, biotin etc
o Meat and fish provide all of B-vitamin including B12
o Milk provide riboflavin and vitamin A and D
o Leafy Greens provide folate, vitamin A, E and K
o Citrus fruits provide Vitamin C
- Vitamin content of the food can be affected by:
 Cooking
 Exposure to light and Oxygen
 Storage and
 Processing
- The Vitamins naturally found in foods can be washed away during prepararion or
destroy by cooking
Important
FORTIFICATION:
The added nutrients may or may not nave been present in the original food
Food that are staples, are often fortified to prevent deficiencies and promote health
Example: Milk fortified with Vitamin D
ENRICHMENT:
Is a type of fortification in which nutrients are added for the purpose of restoring those
lost in processing to the same or higher level than original foods.
Vitamins in the Body
- Vitamins promote and regulate body functions
- For Instance:
o Vitamin C – Essential for the synthesis of neurotransmitters hormones and
Connective tissues
o Vitamin – Antioxidant
o Vitamin A – need for vision, gene expression and cell maturation
o
o
o
Vitamin D – Bone formation
Vitamin K – Blood clotting
B-Vitamins – Act as coenzyme in the metabolism of Carbohydrates, lipids
and proteins
Delivering Vitamins to Cells
- Once absorbed, vitamin must be transported to the cells
- Despite their solubility in water most of the water-soluble vitamins bound to
blood proteins for transport
- Fat-soluble vitamins must be incorporated into lipoproteins or bound to transport
proteins, for example:
Vitamin A, D, E and K all incorporated into Chylomicrons in small
intestinal cells.
Excretion of the Vitamins
- the ability to store and excrete vitamins helps to regulate the amount present in
the body
- With the exception of Vitamin B12, the water-soluble vitamins are easily
excreted
- They are not stored in great extent, so supplies of water-soluble vitamins are
rapidly depleted
- However, it takes few days to develop deficiency symptoms, even when these
vitamins completely eliminated from the diet.
- Fat-soluble vitamins are stored in the liver and fatty tissues, and cannot be
excreted on the urine
- Because they are stored to a larger extent, it takes longer to develop a deficiency
of fat-soluble vitamins.
The Water Soluble Vitamins
-
B- Vitamins and vitamin C
dissolve in water
easily absorbed and excreted
not stored extensively
seldom reach toxic levels
cooking and washing can leach then out of foods
food never deliver toxic doses
large of vitamin supplements can reach toxic levels
The B- Vitamins
Thiamin B1
Riboflavin B2
Niacin
Folate
Pyridoxine B6
B12
Biotin
Pantothentic Acid
Coenzyme
(important) A small molecule that works with an enzyme to promote that enzyme
activity.
The B Vitamins
Act as part of Coenzymes
Help the body Metabolize Carbohydrates, Lipids and protein.
- Five of the B- vitamins
B1, B2, Niacin, Pantothentic acid, and Biotin help releasing energy from
Carbohydrates, Lipids and Proteins.
B6- Protein syntheses
Folate and B12- cell multiplication i.e. blood cells, digestive tract
B-VITAMIN DEFICIENCES
- As long as B-vitamins are present their presence is not felt
- When they are missing, their absence manifest itself in a lack of energy and a
multitude of other symptoms
- B-Vitamins facilitate energy release in every cell
- Thus, in a B-vitamin deficiency, every cell is effected
- Cell renewal depends on energy and protein which in turn depend on B-Vitamins
- In general, single B-Vitamin deficiency never occur
Thiamin and Riboflavin
-
Thiamin (B1) plays critical role in the energy metabolism of all cells
o
Very vital role in maintaining NERVOUS SYSTEM

Nerve processes and their responding tissues, such as the muscles
depends heavily on B1 vitamin

The classic thiamin- deficiency disease “beriberi.”
-
Also involve in the production of sugar “RIBOSE”
-
May be destroyed by:

Heat

Oxygen

Light &

Acid Conditions
- Also affected by Anti-Thiamin factors in Raw Fish & Shell fish
B vitamin Deficiencies
The deficiency of thiamin affects:
- NERVES
- MUSCLES
- HEART &
- OTHER VITAL ORGANS
- A SEVER DEFICIENCY DISEASE IS CALLED “BARIBARI”
CAUSES:
o Extreme Loss of Muscles
o Swelling all over the body
o Enlargement of heart
o Irregular heart beat
o Paralysis and
o Death
-
Alcohol – impairs absorption
Excrete in urine
B1- sources and Recommendations
DRI
1.2mg/day men
1.1 mg/day women
sources
- All notorious food
- Liver
- Whole grains
- Legumes
- Nuts
- Fruits
B2- Riboflavin
- Also act as Coenzyme in energy released reactions
- Also helps to prepare
- Fatty Acid &
- Amino Acids for breakdown
- Can be destroyed by UV Light or Fluorescent light
Part of coenzyme used in energy metabolism, support normal vision and skin health
Deficiency symptoms
Mostly undetected because B1 deficiency symptoms are more severe.
- Rare
- Crack at corners of mouth
- Sore throat
- Hypersensitivity to light
- Reddening of cornea
-
Skin rash
B2- Sources
Same as B1
- Milk, milk products
- Meat
- Liver
- Leafy green vegetable
- Whole grain
Riboflavin destroyed by exposure to light, therefore, milk is stored in cloudy plastic
containers
Niacin (B3)
Nicotinic Acid, Nicotinamind and Niacinamide
Like B1 & B2- Niacin participates in the energy metabolism of every body cell. As
coenzyme
- Niacin deficiency disease “pellagra” appeared in Europe in 1700 when corn
become a staple food
- Cure is niacin
- Amino acid tryptophan
- Well fed people never get “pellagra”
NIACIN IN THE BODY
- Niacin is important in the production of energy as well as in reactions that
synthesize other molecules
Niacin Deficiency Symptoms
- Diarrhea ]
- Dermatitis ]
- Dementia ]
- Death
] “4D Disease”
- Abdominal pain
- Black or bright red swollen smooth tongue
- Weakness
- Dizziness
- Flaky skin rash on area exposed to sun
“4ds”
diarrhea, dermatitis, dementia and death
Niacin Sources
- Tryptophan—60 mg Tryptophan = 1 mg Niacin
- Milk
- Egg
- Meat
- Poultry
- Fish
- Whole grain
- Nuts
Toxicity
Nausea, vomiting, painful flush and rush, sweating
Liver damage, impaired glucose tolerance
Vitamin B6
INVOLVE IN:
-
Protein Metabolism.
Tryptophan = Niacin
Ammonia  Urea
Synthesis of Neurotransmitters
Synthesis of hemoglobin
Synthesis of non-essential amino acids
Maintaining immune function
Also critical in the development of brain & nervous system of a fetus
A person’ s requirement of Vitamin B6 is proportion to protein intakes
VITAMIN B6 AND HEALTH
B6 Deficiency symptoms
- weakness
-depression
-confusion
-irritability
-insomnia
-anemia
-greasy dermatitis – numbness & tingling
-convulsions - may weaken immune system
- heart disease - Seizures
- Deficiency cause Neurological symptoms such as
o Depression,
o Headache
o Confusion
o Numbness and Tingling of fingers n toes
o Seizers
- These may be related to the role of Vitamin B6 in Neurotransmitter synthesis
- Anemia occur due to impaired Hemoglobin synthesis
- RBC are small and pale due to lack of Hemoglobin
- Since Vitamin B6 is needed for amino acid metabolism, the onset of
deficiency can be hastened by a diet that is low in B6 but high in protein
Vitamin B6 and CVD
- Vitamin B6 reduces the risk of heart disease through its role in the breakdown
of Homocysteine
- Large doses of Vitamin B6 (100-1000mg/day) have been successfully used to
reduces elevated Homocysteine
- It has been proposed that a deficiency of:
 Vitamin B6
 Vitamin B12 and
 Folate
May cause Homocysteine accumulation
VITAMIN B6 SUPPLEMENTATIONS
- Vitamin B6 supplements are marketed to help a wide variety of ailments such
as:
 Carpal Tunnel Syndrome
 Premenstrual Syndrome (PMS)
 Poor immune Function
- Some of these claims are found in science others are exaggerated
- Carpal Tunnel Syndrome- No treatment
- Premenstrual Syndrome causes:
 Mood swing
 Food craving
 Tension
 Depression
 Headaches
 Breast tenderness
 Anxiety
 Temper Out Burst and over 100 other symptoms
Vitamin B6 is needed for Neurotransmitters Serotinin and Dopamine
Decrease of serotinin and dopamine levels are associated with PMS
B6 Toxicity B6- can be toxic
Tolerable upper intake level 100 mg/day
Requirement
Roughly proportional to protein intake.
DV 2mg/day
Sources
Meat, fish, and poultry potatoes, leafy green vegetables. fruits
Folate
Come from word Foliage
- Folate and Vitamin B12 have overlapping role in the synthesis of DNA, which is
requires for cells division
- Therefore, some of the same symptoms are seen in sever deficiency of either
Vitamin (folate and vitamin B12)--- most notably is ANEMIA
- Developing Red Blood Cells cannot divide
- To make new cells, tissue must have the vitamin folate.
- Act as a part of a coenzyme important in the manufacture of new cell
- Most vulnerable cells are RBC, WBC, and Digestive tract
Deficiency
Folate easily lost when foods are overcooked, canned, dehydrated or otherwise
processed.
- Anemia
- diminished immunity
- Cervical cancer
- Colon cancer
- Abnormal digestive functions
-Neutral tube defects
Folate and Anemia
-
In U.S, folate- deficiency anemia is common – but that is due to B12
malabsorption
Anemia results when Folate in deficient
Bone marrow cells that develop into blood cells cannot duplicate their DNA and
so cannot divide
Instead, they just grow bigger\these large immature cells are known as
MAGALOBLASTS and can be converted into large RBC called MACROCYTES
That caused fewer mature RBC
It is called Megaloblastic or Macrocytic Anemia
Folate and B12 work as teammates
Folate deficiency may also increase chances of
o CVD
o Colon cancer
o Cervical cancer in women
DRI for women of childbearing age to consume 400 mg/ day in addition to that occurs
in food
Folate deficiency cause group of devastating birth defects as “neutral tube defects”
- effects on thousands of births in U.S each year.
Neural Tube Defect Ranges From
- slight problems in the Spine
- mental retardation
- severely diminished brain size
- death shortly after birth
-
It arise in the first few days or weeks of pregnancy, long before most women
suspect that they are pregnant.
-
3000 infants born in the US each year with neural tube defect.
FOLATE AND HEART DISEASE
-
Folate’s effect on heart disease risk is related to its role in the metabolism of
amino acid Methionine.
When Folate is lacking, Homocysteine produced during methionine metabolism
accumulated
The risk of CVD increases with elevated Homocysteine
Homocysteine levels and risk of CDV are reduced by increase intake of Folate
Folate – Foliage
- Leafy green vegetables i.e. spinach
- Fresh, uncooked veg and fruits
- Eggs
- Orange juice and legumes also contain folate but less available
- Tolerable upper intake level of synthetic folic acid
100mg/day
- Dietary folate equivalent
(DFE)=mg food+ (1.7mg synthetic folate)
Folate Interact with Medication
Ten major groups
- Antacid
- Aspirin
- Oral conceptive
- Anticonvulsant
Cynocobalamine Vitamin B12
- unique vitamin
- found exclusive in animal products
- can be made by bacteria & fungi, but not by plant
- Diet that do not include animal products, must include supplement.
B12 and folate- depend on each other for activation
- B12 maintain the sheaths that protect nerve fibers
- Also help folate to do its blood building work
- Involve in DNA synthesis
- Pernicious anemia
- Large, immature RBC
- Creeping paralysis
- Malfunction of nerves and muscles
- high dose of folate often clear up blood conditions but other B12 deficiencies
continue undetected
- B12 absorption require an
“intrinsic factor”
- A compound made in stomach
- Stomach acid liberate B12
- Attach with intrinsic B12
- Attach with intrinsic factor
- Absorb through S. intestine
- Some people have inherited defect
- Diagnosing B12 problems is difficult
- Body store up to 6 yrs worth of vitamin B12
Sources
Animal products
-meat, fish, poultry milk, cheese, eggs
synthesize only by microorganism.
-
Biotin
Act as Coenzyme
Biotin requires for:
o Cell Growth
o DNA Synthesis
o Fat Synthesis
o Energy Metabolism
o Amino Acid metabolism
o Glycogen Synthesis
-
Biotin was discovered when rats fed protein derived from raw egg white
Rats developed a syndrome of :
o Hair loss
o Dermatitis and
o Neuromuscular dysfunction
- those symptoms were caused by protein “ADVIN” that present in raw egg
white and tightly bind biotin and prevent its absorption.
Biotin in the Diet
- Good sources of biotin include:
 Liver
 Egg Yolk
 Yogurt and
 Nuts
`- Fruits and meat are poor sources of Biotin.
How much Biotin do we need
- It is difficult to estimate biotin requirements
- Because some Biotin is produced by bacteria
- No RDA but AI of 30 micro grams per day has been established for adult men
and women
Biotin in the Body
Is a cofactor for several enzymes use in:
- energy metabolism
- fat synthesis
- amino acid metabolism
- glycogen synthesis
Deficiency symptoms
- abnormal heart action
- loss of appetite, nausea weakness, depression, dry around eyes, nose and
mouth
Pantothenic Acid
-
as Coenzyme involve in energy metabolism
Also help:
o Maintain Blood glucose
o
Synthesis of
 Lipids
 Steroid Hormones
 Hemoglobin
- Got its name from Greek word pantos meaning “ From Everywhere”
- Is widely distributed in foods
- Particularly abundant in:
 Meat
 Egg
 Whole grains and Legumes
o Lesser amount in :
 Milk
 Vegetables and
 Fruits
- No RDA but and AI of 5 mg/day has been recommended
Pantotenic Acid in Body
Is a component of a key coenzyme that makes possible release of energy from
nutrients
- also help synthesis of lipids, neurotransmitters steroid hormones
hemoglobin
Deficiency Symptoms
Vomiting, insomnia, fatigue hypoglycemia, sensitivity to insulin.
-
-
Vitamin C
Known as Ascorbic Acid or Ascorbate
Ascorbic Acid- “no- scurvy Acid”
Act as Antioxidant
Help maintain immune system
Also help in absorption of iron
Help specific enzymes perform their job__
Such as, enzymes involved in formation and maintenance of, tissue
protein, collagen.
Involve in release of stress hormone.
also act as cofactor in the production of carnitine
protect and recycle vitamin E
In times of stress, the body does use more vitamin C than usual because of vitamin is
involve in the release of stress hormone- but that is usually very small and that
requirement can be met easily by food.
Reactions Requiring Vitamin C
Connective Tissue:
- Vitamin C require in reactions where (OH) hydroxyl group is added to
other molecules
-
Two such reactions are essential for the formation of Collagen, the
protein that forms the base of all connective tissues
Vitamin C also serves in reactions needed for the synthesis of other cell compounds
including:
o Neurotransmitters
o Hormones such as
 Thyroids and
 Steroid Hormones
o Bile acids and
o Carnitine ( needed for fatty acid synthesis)
Vitamin C as a General Antioxidant
- Vitamin C also function as an antioxidant
o Oxidative stress refers to a serious imbalance between the amount
of reactive Oxygen molecules and the amounts of antioxidant
defenses available
- Oxidative stress has been related to:
 Aging process
 Development of cancer and
 Heart diseases
 Vitamin C, Vitamin E, carotenoids and mineral selenium
help to fight free radicals
The Role of Vitamin C:
- Vitamin C acts as an antioxidant in the blood and other body fluids
- It can destroy Superoxide Redicals and Free Radicals before they can
damage Lipids and DNA
- Vitamin C has also been shown to scavenge reactive oxygen molecules in
 WBC
 The Lungs
 The Stomach Mucosa
- It also regenerates the active antioxidant form of Vitamin E
Vitamin C requirement
DRI for men 90 mg women 75 mg
Smoker and “passive smoker”
Need higher amount 125 mg/ man
110 mg/women
Deficiency symptoms
Anemia, pinpoint hemorrhages frequent infections, bleeding gums, loosen
teeth, hysteria bone fragility, joint pain failure of wounds to heal.
-
When Vitamin C intake is below 10mg/day the symptoms of SCURVY
may appear.
These symptoms reflect the role of Vitamin C in the maintenance of
collagen and blood vessel integrity
-
Without vitamin C, bond holding collagen molecules can not be formed
and maintained
- Resulting in poor wound healing
- Reopening of previously healed wounds
- Bone and joint aches
- Bone fractures
- Improperly formed and loose teeth
- Due to weakened blood vessels ruptured capillaries:
o Small skin discoloration appears
o The gums bleed and
o Bruising occurs easily
- Anemia may occur from impaired iron absorption
The Psychological manifestations of Scurvy include depression and hysteria
High vitamin C Doses and Toxicity
- Generally considered nontoxic
- Percentage of dose absorbed decreases as the size of the dose increases
- Besides, Vitamin c absorbed in excess of need is excreted by the kidney
- Most common symptoms with doses of 1 gram or more are:
 Diarrhea
 Nausea and
 Abdominal cramps
- These are caused when unabsorbed Vitamin C draws water into the
intestine
- Another concern with Vitamin c supplements is damage to tooth enamel
- Vitamin C is an Acid that is strong enough to dissolve tooth enamel
- High intake of Vitamin C should be avoided by individuals:
 Prone to kidney stones
 Who are unable to regulate iron absorption
 Those with sikle-cell anemia
- insulin response
- kidney stone
- alter acid/ base balance
- interfere in Vitamin E actions
Vitamin C Supplements
-
1/3 U.S population take Vitamin C supplement in hope to prevent
 Common cold or
 As an antioxidant
Vitamin C and Common Cold
- Vitamin C do not reduce the incidence of Cold
- But do cause a reduction in duration and severity of cold symptoms
- The effect of vitamin C on cold symptoms may be due to:
o Its direct antiviral effect
o Its antioxidant effect
o Its role in immune system or
o Its ability to increase breakdown of Histamine
Vitamin C and CVD
- Vitamin C supplements have been suggested to reduce the risk of CVD by:
o Reducing Blood pressure
o Reducing Blood cholesterol
o Protecting LDL from Oxidation
The Need For Vitamin C
- Adult DRI for
 Men
90 mg
 Women
75 mg
o For cigarette smokers
 Men
125 mg
 Women
110 mg
Vitamin Sources
- citrus fruits
- Cabbage type veg.
- dark green veg.
- cantaloupe
- strawberries
- pepper
- lettuce
- tomatoes
- potatoes
- mangoes
FREE RADICAL
- Is a molecule with one or more unpaired electrons
- An electron without a partner is unstable and highly reactive
- To regain stability, free radical finds a stable but vulnerable compound
from which to steel an electron
- With the loss of an electron formerly stable molecules become a “FREE
RADICAL” itself
- And steals an electron from some other nearby molecule
- Setting off an electron snatching chain reaction
- Free radicals are like spark
- Starting wildfires that leads to widespread damage by Oxidative Stress
- Free-radical damage commonly disrupts unsaturated fatty acids in cell
membranes
- Damaging the membranes ability to transport substances into or out of
cell
- Free-radicals also cause damage to cell proteins and DNA
- And disrupting all cells that inherit the damaged DNA
- More than 200 diseases are linked with oxidative stress among them are:
 Age related blindness
 Arthritis





Cancers
CVD
Cataracts
Kidney diseases and
Other complications of diabetes
The Body’s Defenses against Free Radicals
- Two main systems
o Reserves of Antioxidants
o Enzyme Systems
- These are not 100% efficient
o If insufficient Radical-Fighting Agents are present
o If Free-Radicals become excessive or
o The body repair systems cannot undo all of the damage
Serious health problems can develops
-
Antioxidant Nutrients
Vitamin E & C actively scavenge & destroy free radicals in body
Once oxidized, some vitamin E & C can be reactivated as antioxidants
again, some are discarded
Supplies of dietary antioxidants must be replenished as rapidly as they are
used up.
Vitamin E defends lipids in cell membrane
Vitamin C neutralize free radicals from polluted air
o Also restore vitamin E to active form
FAT SOLUBLE VITAMINS
VITAMIN A
- First fat- soluble vitamin to be recognized
- Still very much a focus of research
- Vitamin A found in two forms
 IN PLANTS AS CAROTENOIDS –(inactive or precursors)
 IN ANIMALS AS RETINOIDS – (active or preformed)
 Retinol—involve in reproduction, Bone formation and
store in Livers
 Retinal—involve in night and color vision
 Retionic Acid—involve in cell growth and cell
differentiation
- Retinol store in liver
- Cells converts retinol into other two forms as needed
- 90% vitamin A store in the liver.
- PREFOREMD are found in animal food such as:
 Liver
 Fish
 Egg yolk and
 Dairy products
- PROVITAMINS are found in plant food
o About 50 out of 600 carotenoids provide some levels of vitamin A activity
o Beta-carotene is the most potent precursor
o It found plentiful on Carrots, squash, leafy greens and other red and
yellow vegetables and fruits
Vitamin A in the Digestive Tract
- Both RETINOIDS and CAROTENOIDS are bound to proteins in food
- To be absorbed, PEPSIN and other protein digesting Enzymes must release them
from protein.
- Than released carotenoids and retinoids must combine with bile acids
- That facilitate their diffusion into mucosal cells
- Absorption of PREFORMED vitamin A is efficient (70% to 90%)
- CAROTENOIDS are less well absorbed and absorption decreases as intake
increases.
- Once inside mucosal cell, much of the Beta-carotene in converted to RETINAL
and than RETINOL
- Insufficient fat intake (less than 10g/day) can reduce Vitamin A absorption
- Diseases that cause fat malabsorption can also interfere with Vitamin A
absorption
Vitamin A in the Body
- RETINOIDS and carotenoids are transported from the intestine in
CHYLOMICRONS
- These Lipoproteins deliver retinoids and carotenoids to the tissues.
- In Liver some CARODINOIDS can be converted in to RETINOL
- To move from liver store to the tissues vitamin A must be bound to
Retinol_Binding Proteins
- Different forms of Vitamin A have different function
- Retinol and retinal can be inter-converted
- RETINAL is the form that is important fro vision
- Retinoic Acid important in gene expression and cell differentiation, growth and
reproduction
- Carotenoids, that are not converted in to Retinoids may act as Antioxidants or
provide other biological functions
ROLE OF VITAMIN A
Versatile vitamin role in:
- Vision
- Cell differentiation
- Cell maturation
- Immune system
o T-Cells
-
o Epithelial Layers
Maintenance of body linings & skin
Bone
Normal growth
Reproduction
 Normal development of fetus
 Production of sperms
Hearing
Taste
MOST FAMILIAR FUNCTION IS IN EYE SIGHT
Vitamin a play indispensable role in roles in two areas
- In the perception of light at the retina
- Maintenance of a healthy & crystal clear outer window, the cornea
Light pass through the cornea & strikes the cells retina, bleach many molecules of the
pigments rhodopsin that lie with in those cells.
- When bleach occurs, the vitamin. A broken off, initiating the signal that conveys
the sensation of sight to the optic center in the brain.
-
Vitamin A reunites with the pigment
Little vitamin. A destroyed each time
Fresh vitamin. A is needed to replenish the supply
If supply begins to run low, a lag occurs before eye can see again after a flesh or
bright light at night called night blindness.
In advance stage of deficiency a protein keratin accumulate at cornea called
keratinization.
If deficiency is not corrected it can worsen to xerosis.
Then to thickening & permanent blindness called xerophthalomia.
VITAMIN A IS ALCO NEEDED BY ALL EPITHELIAL TISSUES
Skin & all the protective linings of:
The lungs (respiratory tract)
- Intestine (digestive tract)
- Vagina
- Urinary tract &
- Bladder
- Skin
Vitamin A help
Cell differentiation
e.g. goblet cells
Bones dismantling
CELL DIFFERENTIATION
The process by which immature cells are stimulated to mature and gain the ability to
perform function characteristic of their cell type.
Gained a reputation as an
-“Anti-infective vitamin”
- Emerging area of research concern the role of vitamin A in the regulation of the
genes that produce proteins immunity.
REGULATING GENE EXPRESSION AND CELL DIFFERENTIATION
Cell differentiation is the process whereby immature cells change in structure and
function to become specialized, for example:
In bone marrow, some cells differentiate in to WBC, whereas other differentiate to
form RBC.
-
Vitamin A affect cell differentiation through its effect on GENE EXPRESSION
It means that it can turn on or off the production of certain proteins that regulate
function within cells.
MAINTENANCE OF EPITHELIAL TISSUES
- Vitamin A is necessary for the maintenance of epithelial tissues
- This type of tissue cover external body surfaces and linings of internal cavities
and tubes such as:
 Skin
 Linings of eye
 Intestine
 Lungs
 Vagina and
 Bladder
- When Vitamin A is deficient, epithelial cells do not differentiate normally
- For example, the epithelial tissue of many body surfaces contain cells to produce
mucus
- When mucus-secreting cells die, new cells do not differentiate properly and
instead become cells that produce a protein called KERATIN
- Keratin is a hard protein that make up hair, finer nails etc
- That make epithelial surface hard and dry
- This process is known as KERATINIZATION
- That increases the chances of infection
- The risk of infection compounded by the fact that vitamin A deficiency also
decrease immune function
- All epithelial tissues are affected by Vitamin A deficiency but eyes are
particularly susceptible to damage.
- The mucus in the eye normally provides lubrication, washed away dirt and other
particles, also help destroy bacteria
When vitamin A is deficient, the lack of mucus and build up of Keratin cause
Cornea to dry and leave the eye open to infection
REPRODUCTION, GROWTH AND IMMUNITY
- The ability to Vitamin A to regulate the growth and differentiation of cells make it
essential through out life
- In reproduction, Vitamin A is hypothesize to play a role during early embryonic
development by directing cells to form the shapes and pattern needed
- Poor overall growth is an early sign of Vitamin A deficiency in children
- Vitamin A affects the activity of cell form and break bones
- In immune system Vitamin A needed for the differentiation than produce different
types of immune cells
VITAMIN A DEFICIENCY
About 10 million children suffer- sever vitamin A deficiency
About 300 million suffer- milder deficiency
SYMPTOMS
- Anemia ( microcytic anemia)
- Cessation of bone growth
- Painful joints
- Impaired enamel formation
- Cracks in teeth
- Changes in intestinal & other body linings
- Night blindness
- Keratinization, xerosis to xerophthalmia
- Kidney stones, impaired growth
- Frequent infections of respiratory, digestive system.
-
VITAMIN A TOXICITY
Hair loss
Stunted growth
Joint pain
Bone & muscle soreness
Cessation of menstruation
Nausea
Diarrhea
Rashes
Abdominal pain
Serious damage to the liver
Pregnant women- 3-4 time caused malformation of the fetus
Children- chewable vitamins as candy
Adolescents- massive vitamin A dose is a mistaken belief- correct acne.
Accutane- derived from vitamin A but chemically altered.
-
EARLIER SYMPTOMS OF VITAMIN A OVERDOSE
Loss of appetite
-
Blurred vision
Growth failure in children
Headache
Fever
Itching of the skin
Irritability
VITAMIN A RECOMMENDATIONS
Proportional to the body weight
DRI- 900 ug man
700 ug woman
Tolerable upper level
3000 ug
BETA- CAROTENE
12 ug of B-Carotene
=1 ug retinol
B-Carotene—Non Toxic
24 ug other carotenoids
=1 ug retinol
RETINOL ACTIVEITY EQUIVALENTS
(RAE)
Measure of vitamin A activity of B-Carotene & other vitamin A precursors that reflects
the amount of retinol that the body will derive from that precursors.
SOURCES OF VITAMIN A
Active vitamin A source
- Liver
- Fish oil
- Milk & milk products
- Butter
- Egg & fortified cereals
Vegetables & fruits contain vitamin A- Precursor
B- Carotene
i.e. Carrots, mango, apricots, spinach, etc.
VITAMIN D
Different from all other nutrients- Can be synthesized in body.
Also known as SUN SHINE VITAMIN
ROLE OF VITAMIN D
- As a member of a large group of nutrients & hormones that interact to maintain
blood Ca & P levels & bone integrity. Those including:
o Vitamin C
o Vitamin K
o Hormones
o
Protein Collagen a the minerals
 Magnesium
 Fluoride
- Many of these interactions take place at genetic level
- Vitamin D is Indispensable for all body tissue, i.e.
Muscles
Nerves
Glands
ALSO PLAY ROLE IN THE WORKING OF:
- Brain
- Heart
- Pancreas
- Skin
- Reproductive organs
- Cell maturation
- Immune system
VITAMIN D FUNCTIONS AS A HORMONE:
- Act on bones
- Intestine &
- Kidney
Only a few foods are natural source of Vitamin D
- Liver
- Fatty Fish such as Salmon
- Egg Yolk
These food contain Vitamin D3, same type as made in our skin
Foods like milk and margarine are fortified with vitamin D3 or Vitamin D2
VITAMIN D IN THE BODY
- Vitamin D from diet and from synthesis in the skin is “INACTIVE”
- Liver and than kidney alter it chemically to make it ACTIVE
- In Liver an Hydroxyl group (OH) is added to form 25-Hydroxy vitamin D3
- Than kidney add an other “OH” group to make ACTIVE form of Vitamin D3,
called 1, 25 – dihydroxy Vitamin D3
- The principal function of vitamin D is to maintain normal blood level of Ca
and P.
- When blood Ca level drops too low the parathyroid gland releases Parathyroid
Hormone (PHT)
- PHT stimulate enzymes in the kidney to convert 25-Hydroxy Vitamin D3 to the
ACTIVE form
- Active Vitamin D regulate Ca and P balance by altering GENE EXPRESSION in
cells at the intestine and bone
- At the intestine, vitamin D increases the absorption of Ca and P
- This occurs because Vitamin D increases the expression of GENE that code for
intestinal calcium-transport-protein
-
At the bone. Vitamin D works with PHT to increase bone breakdown
Vitamin D also acts with PHT to increase the amount of Ca retained by the
kidney
Vitamin D simultaneously act on:
 Small intestine
 Bones and
 Kidney
VITAMIN D DEFICIENCY
Any disease affecting either the liver or kidneys may upset vitamin D production and
may lead to bone deterioration,
RICKETS IN CHILDRENS:
- Bowed legs
- Knock knees
- Beaded ribs
- Protruding (pigeon) chest
- Lax abdominal muscles
Osteomalacia or adult rickets occurs in women with low Ca intake & little exposure to
sun.
- Repeated pregnancies & breast feeding
FACTORS AFFECTING SUN EXPOSURE & VITAMIN D SYNTHESIS
- Air pollution
- City living- Tall buildings
- Clothing
- Homebound
- Season
- Time of day
UV Rays of sun that promote vitamin D synthesis cannot penetrate:
- Clouds
- Smoke
- Smog
- Heavy clothing
- Window glass
- Sunscreens
VITAMIN D OVERDOSE
Most toxic of all vitamins chronic ingestion of excesses may be directly toxic to
the bone, kidneys, brain, nerves, heart & arteries
SYMTOMS:
- Appetite loss
- Nausea
- Vomiting
- Increase urination & thirst
- Sever psychological depression
- Kidney stone
-
VITAMIN D
IF OVERDOSES CONTINUE
Raises blood mineral level to dangerous level
Ca deposit in soft tissues such as:
o Heart
o Blood vessels
o Lungs
o Kidneys
VITAMIN D RECOMMENDATION
19- 50 years of age 5 ug
51- 70 years of age 10 ug
71> years of age 15 ug
TOLERABLE UPPER INTAKE
50 ug in 2000 iu
-
SUMMARY
VITAMIN D
Raises mineral level in blood Ca & P.
Bone formation & maintenance.
Deficiency can cause ricket & osteomalacia.
Most toxic of all vitamins.
Sun exposure makes vitamin D in skin.
VITAMIN D SOURCES
-
Sunlight
Fortified milk 1c= 2.5 ug
Salmon
3oz=4.3 ug
Shrimp
3oz=3.0 ug
Egg
VITAMIN E
Discovered 80 years ago in vegetable oils- Necessary for reproduction in rats.
Named “Tocopherol”
“Tokos” means “Off Spring”
“Pherein” means “To Bear”
Later on it was named vitamin E.
- 4 tocopherol compounds have been identified- Each designated as alpha, beta,
gamma & delta.
Alpha- tocopherol is the standard of vitamin E activity in the body.
DRI recommendations are based on Alpha- tocopherol
In 1968 Vitamin E was officially recognized as an essential nutrient
Vitamin E has been promoted as:
 A cure of infertility
 An anti-scar medication
 Defense against air pollution and
 A fountain of youth
VITAMIN E IN DIET
The majority of vitamin E in the diet comes from:
- Vegetable Oils
- Products such as:
- Margarine
- Salad dressing
- Shortenings
- Soybean, Corn and Safflower Oils
ROLE OF VITAMIN E
Act as an antioxidant
- By being oxidized itself, it protects the PUFA and other vulnerable components
of the cells.
- Protects all the cells lipids & related compounds i.e. vitamin A.
- Specially play vital role in tissues where cells are exposed to high oxygen
concentration
o Lungs
o RBC
o WBC etc.
-
VITAMIN E ALSO TAKE PARTS IN:
Normal nerve development
Normal immune system
May also defend against heart disease.
Also inhibit an enzyme that allows the buildup of Atherosclerotic plaque
Increase the synthesis of enzyme needed to produce eicosinoides that help reduce
blood pressure and reduce blood clot formation
Also defend cells from damage by heavy metals, such as lead and mercury and
toxins such as benzene
Also protects against environmental pollutants such as OZONE
RESEARCH HAS DISCREDITED ALL CLAIMS THAT VITAMINE IMPROVES
- Athletic endurance & skill
- Enhances sexual performance
or
-
-
Cures sexual dysfunction in males.
VITAMIN E DEFICIENCY
Vitamin E deficiency is rare in human
Because:
o It is wide spread
o It is store in liver
o Recycle
Vitamin E deficiency in human occurs in premature babies
Without vitamin E infants RBC rapture
(Erythrocyte hemolysis)- Infant become anemic
In adult deficiency associated with disease that cause malabsorption of fat. i.e.
disease or injury of liver, gallbladder or pancreas
DEFIENCY OF VITAMIN E ALSO CAN BE CAUSED BY:
- Extremely low fat diet
- Fat replacer
- Highly processed or convenience food
-
VITAMIN E DEFICIENCY SYMPTOMS
Loss of coordination & reflexes with impaired movement
RBC breakage, anemia
Leg cramps
Vitamin E sources
Vegetable oils
Fruits
Vegetables (especially leafy green veg.)
Grains
Wheat germ
Meat, poultry, fish, egg, milk, nuts, seed contribute smaller percentage.
Animal fat have almost none
Vitamin E- Requirement and Toxicity
DRI 15mg/day
With high intake of PUFA
Can take up to 800mg
Toxicity
- No real toxicity from VITE in natural food- but supplemtn
- May cause mental and physical retardation
- Blured vision
- Fatgue
- Large doses may increases the effect of anticoagulant medications
- 50% in brain hemorrhage in smoker-50mg
-
Vitamin E summary
act as an antioxidant- specially important for those cells that are exposed to high
O2 concentration
Vitamin- E deficiency is rare in human being
Widely distributed in plant food
Destroyed by high heat
Toxicity is rare
Vitamin K
-
One of the few Vitamins about which extravagant clams are not made
Found in several form
Phylloquinone- found in plants
Menaquinone- found in:
 Fish oils
 Meats and
 Synthesized by bacteria
- Only small number of foods provide significant amount of Vitamin K
Liver, leafy green vegetables and some vegetable oils are good source
VITAMIN K IN BODY
- Vitamin K is neede for the production of the blood-clotting protein called
prothrombin and other specific Blood-clotting factors
- These proteins are needed to produce FIBRIN
- FIBRIN form the structure of blood clot
- Several Vitamin-K dependent proteins are involve in bone mineralization and
demineralization, with Vitamin D
- Vitamin k may also reduce Hip fructure
Sources
- Intestinal bacteria
Dark green leafy Vegetables. i.e. spinach, 300 mg/3oz
Lettuce, broccoli, cabbage family 100 mg/3oz
- Canola and soybean oil
Vitamin K Deficiency and Toxicity
Deficiency
- Rare
Exceptions are:
-antibiotic
-new born
Tolerable upper intake level- not yet set
Toxicity
- Rare
- Can result when supplement of synthetic vitamin K are given
- It causes
o breakage of RBC
o releases the blood cell pigment (bilirubin) leads to jaundice
o brain damage
Vitamin Supplements
-
Higher amount of Vitamin leave the category of nutrition and enter
Pharmacology
Can have side effects like other drugs
Acute overdoses are the potential for chronic, low-level nutrient toxicity
-
These people might need vitamin supplements
people with nutrients decency
women in their child bearing age
pregnant or lactating women
newborn/ infants
elderly people
victims of aids etc.
drugs and alcohol user
Selection of A Multinutrient Supplement
- An appropriate supplement provide all Vitamins and Minerals in amount:
 Smaller than or
 Equal to or
 Very close to the Intake Recommendations
- Avoid any preparation that, in a daily dose, provides more than the DRI
intake, specially of:
 Vitamin A
 Vitamin D or
 Any Mineral
AVOID THESE:
- High dose of Iron
- Labeled as “ORGANIC” or “NATURAL” preparations with added
substances
- “HIGH POTENCY” or “ THERAPEUTIC DOSE” supplements- More is
not better
- Items not needed in Human nutrition, such as Carnitine and inostol
- “TIME RELEASE”- Nutrients are incorporated into the tissues where
they are needed whenever they arrive
- “STRESS FORMULA”- although the stress response depends on certain
B-Vitamins and Vitamin C-Recommended amount provide all
- Pills containing extract of Parsley, alfalfa and other vegetables
components
- “TONICS”- They are generally poor in Vitamins and Minerals and high
in alcohol
If you decide to take a supplement examine the ingredients on supplement labels and
choose one that satisfy you needs
NUTRITION AND CANCER PREVENTION
- 35% CANCER CASES ARE RELATED TO DIET
CANCER SITE
RISK FACTOR
Breast
High calorie and or alohol intake, obesity, low fruit and vege.
intake, low physical avtivity
Colon or rectum High red meat, excessive alcohol, low fiber, low calcium & vitamin
D, obesity & low physical activity
Esophagus
Excessive alcohol intakes, low intake of fruitand vegetable, obesity
Lungs
Low fruit and vegetable, lowlevel of physical activity
Ovary
High fat diet,obesity,low fruit and vegetable, low physical activity
Prostate
High saturated fat, obesity, low physical activity
Stomach
Regular consumption of smoked foods, and food cures with salt or
nitrite compounds, low fruits & vegetables
Liver
aflatoxin-conatining grains,smoked food and foods cures with salt or
nitrite compunds
Mouth & Throat Excessive alcohol, low fruit and vegetables