Vitamins asif

Welcome to the Presentation OnVITAMINS

Presented By:Asifur Rahman01747137920North South University

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

Vita

min


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

North South UniversityMechanism 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

North South UniversityIndications of Vitamin-D

Hypocalcemia in patients on chronic dialysis & hypoparathyroidism1.Rickets 2.Osteomalacia; 3.Hypocalcemic tetany in premature infants

North South UniversityFunction

• 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


North South UniversityContra 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 disorientationiv. Damage to the kidneys v. Kidney stonesvi. Nausea, vomiting, constipation, poor appetite,

weakness, and weight loss

North South UniversityVitamin 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

North South UniversityFUNCTION

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.

North South UniversityBiosynthesis 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


Health & Medicine

Vitamins asif