Vitamins asif

Welcome to the
Presentation
OnVITAMINS
Presented By:
Asifur Rahman
01747137920
North South University

Definition
Vitamins are organic compounds which are needed in small
quantities to sustain life. We get vitamins from food, because
the human body either does not produce enough of them, or
none at all.
Sometimes the compound is a vitamin for a human but not for
some other animals. For example, vitamin C (ascorbic acid) is
a vitamin for humans but not for dogs, because dogs can
produce (synthesize) enough for their own needs, while
humans cannot.

Characteristics
Essential nutrients that must be included in every day diet.
Water soluble vitamins cannot be stored in human tissues.
Their excess is excreted with urine.
Significant amounts of fat soluble vitamins can be stored
in adipose tissue and the liver.

1. Acts as co-enzyme.
Example: All B vitamins
2. Acts as bio-regulators.
Example: Vitamin A for retinol/ retinal cycle.
3. Acts as biological co-transporter.
Example: Vitamin D in bone formation
4. Anti-oxidant.
Example: Vitamin C&K
5. Maturing factor for blood clotting.
Example: Vitamin K
6. Stimulate and give strength to digestive and nervous system
Function

Classification
Fat Soluble
• Vitamin A,D,E,K
• Stored in liver and adipose tissues
• Large hydrophobic structure
• Needed every three days
Water
Soluble
• Vitamin B group & C
• Not stored in body
• Small hydrophilic structure
• Needed daily
Vitamin

1. Chemical names - retinol, retinal.
2. Precursor- beta carotene
3. Deficiency may cause night-
blindness and keratomalacia (eye
disorder that results in a dry cornea).
4. Good sources include: liver, cod
liver oil, carrot, broccoli, sweet
potato, butter , spinach, pumpkin,
some cheeses, egg, milk, apricot.
Vitamin A
Vit A structure

Functions
1. Promotes good night vision and normal vision.
2. Promotes cell differentiation.
3. Supports immune system.
4. Promotes growth and reproduction.

Vitamin A (all-trans retinol) is
converted in the retina 11-cis-
retinal
11-cis-retinal, while attached to
opsin in rhodopsin is isomerized
to all-trans-retinal by light
All-trans-retinal is then released
from opsin and reduced to all-
trans-retinol.
All-trans-retinol is isomerized to
11-cis-retinol in the dark, and
then oxidized to 11-cis-retinal.
Mechanism of action

Mechanism of Action

1. Chemical names - ergocalciferol
(Vitamin D2) , cholecalciferol
(Vitamin D3)
2. Deficiency may cause rickets,
osteomalacia
3. Good sources: produced in the
skin after exposure to ultraviolet B
light from the sun or artificial
sources.
Also found in fatty fish, eggs, beef
liver, and mushrooms.
Vitamin D
Vit D structure

Indications of Vitamin-D
Hypocalcemia in patients on chronic
dialysis & hypoparathyroidism
1.Rickets
2.Osteomalacia;
3.Hypocalcemic tetany in premature infants

Function
• Vitamin D helps the body absorb calcium. Calcium
and phosphate are two minerals that are essential for
normal bone formation.
• Help block the release of a specific hormone
(parathyroid hormone). This hormone reabsorbs bone
tissue, which makes bones thin and brittle.
• Vitamin D may also play a role in muscle function
and the immune system

Vitamin D, as either D3 or D2, does not have significant biological
activity. Rather, it must be metabolized within the body to the
hormonally-active form known as 1,25-dihydroxycholecalciferol. This
transformation occurs in two steps.
• cholecalciferal is hydroxylated to 25-
hydroxycholecalciferol by the
enzyme 25-hydroxylase
Within
the
liver,
• 25-hydroxycholecalciferol serves as a
substrate for 1-alpha-hydroxylase,
yielding 1,25-
dihydroxycholecalciferol, the
biologically active form.
Within
the
kidney,
Mechanism of action

Contra Indicaiton of Vitamin-D
High Blood Calcium level causes :-
i. Calcium deposits in soft tissues such as the
ii. Heart and lungs
iii. Confusion and disorientation
iv. Damage to the kidneys
v. Kidney stones
vi. Nausea, vomiting, constipation, poor appetite,
weakness, and weight loss

Vitamin E
• Chemical names - tocopherols, tocotrienols
Deficiency is uncommon. May cause mild hemolytic anemia in newborns
• Good sources include: kiwi fruit, almonds, avocado, eggs, milk, nuts, leafy
green vegetables, unheated vegetable oils, wheat germ, and wholegrains.
Vit E structure

Functions
 Vitamin E protects red blood cells and helps prevent destruction
of vitamin A and C
 Vitamin E is also important in the formation of red blood
cells
 The body also needs vitamin E to help keep the immune
system strong against viruses and bacteria.
 Vitamin E is an antioxidant that protects body tissue from
damage caused by substances called free radicals

Mechanism of action
Free radicals, such as superoxide, hydroxyl ions and nitric oxide
all contain an unpaired electron. These radicals can have a
negative effect on cells causing oxidative damage that leads to
cell death.
Antioxidants, such as vitamin E, prevent cell damage by binding
to the free radical and neutralising its unpaired electron. For
example, when vitamin E binds to OO· or O2
· they form an
intermediate structure that is converted to a-tocopherylquinone.

VITAMIN C
 Also known as L-ascorbic acid it is an essential nutrient for
humans.
 It is needed for metabolic reactions in all plants and animals.
 It is a water soluble vitamin that is necessary for growth and
development
L-ascorbic acid
structure

History
 17th century – sailors got scurvy on ships and ship
surgeon, James Lind, prescribed lemon juice as
preventative. Performed an experiment that proved that
lemon juice prevents
scurvy.
 We now know today that
it is because of the Vitamin
C in the lemon that prevents
Scurvy.

Found in
 Mostly in citrus fruit and juices
(limes, lemons, oranges, peaches,
strawberries, bananas, and
grapefruits)
 Also in cabbage, broccoli,
cauliflower, leaf lettuce, tomatoes,
potatoes, and beans.
 There are also vitamin C pills and
other things for supplements

FUNCTION
 Vitamin C is needed for the growth and repair of
tissues.
 It helps the body make collagen an important protein.
 Vitamin C is needed for healing wounds, and for
repairing and maintaining bones and teeth.
 It also act as anti-oxidant by scavenging free radicals
directly in aqueous phases of cell.
 It also help in bone formation.
 It helps in the synthesis of cortico-steroid hormone.

MECHANISM OF VITAMIN C
 Vitamin C reaches every cell of the body and plays a role
in the making and protecting of our connective tissue that
holds the body together.
 Helps the immune system fight off diseases
 Helps the cardiovascular system by facilitating fat
metabolism
 Helps the nervous system by converting amino acids into
neurotransmitters
 Vitamin C’s formation of collagen protects teeth and
bones.

Biosynthesis and Metabolism
 Many Animals can synthesize ascorbic acid from
glucose via uronic pathway.
 Man and other primates cannot synthesize vitamin
C due to lack of single enzyme L-Gluconelactone
Oxidase
 As it is not synthesize endogenously, we are depend
on dietary sources.
 It is easily destroyed by heat, increased pH and light
and also very soluble in water.

Excretion
 It is excreted primarily by Kidney
 Their amount of excretion is
dependent on the degree of tisse
saturation.
 Normal excretion will occur if intake
is normal
 Due to excess metabolism or
excessive intake of Vitamin C it may
retained.

DAILY ALLOWANCE

DEFICIENCY
 Weight loss
 fatigue and joint pain
 scurvy
 reduced resistance to
colds and infections
 slow healing of
wounds and
fractured bones
 Also some oral
malfunction.

SIDE EFFECT
 Diarrhea
 dizziness or faintness
 flushing or redness of skin
 headache
 increase in urination (mild)
 nausea or vomiting
 stomach cramps
 Side or lower back pain

Vitamins asif

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