Vitamins are organic substances that are essential for life and normal functioning of the body. There are 13 vitamins classified as either water-soluble or fat-soluble. Water-soluble vitamins dissolve in water and cannot be stored in the body for long, while fat-soluble vitamins are stored in body tissues. Vitamins perform important roles like energizing metabolism, regulating cell growth, and enabling vision in low light. Common sources of vitamins include foods like fruits, vegetables, meat, and dairy. Deficiencies can lead to conditions like scurvy or rickets.

2. What are vitamins?
 Vitamins and minerals are substances that are found in
foods we eat.
 Vitamins are necessary for growth and vitality. They are
found in all natural foods. We must obtain vitamins from
foods or dietary supplements.
 Vitamins are organic substances necessary for life.
Vitamins are essential to the normal functioning of our
bodies, and except for a few exceptions, cannot be made by
our bodies.
 There are thirteen vitamins classified as either water
soluble (C and B complex) or fat soluble (A, D, E and K).

3. What are the functions of
vitamins?
 energize our metabolism
 regulate our metabolism
 help form blood clots when we bleed
 enable cell growth
 help us see in color instead of black and white

4. Two kinds of vitamins
Water-soluble Vitamin
a Fat-soluble Vitamin

5. Fat Soluble Vitamins
 A fat-soluble vitamin is a vitamin that can be stored in
the liver and fat tissues of your body until your body
needs them. Vitamins A, D, E and K are fat-soluble
vitamins. Fat-soluble vitamins can be stored in your
body for up to six months
 Fat-soluble vitamins are absorbed, together with fat
from the intestine, into the circulation

6. Vitamin A (fat-soluble)
 Sources: Dairy products, eggs, liver. Can be converted
by the body from the beta-carotene found in green
vegetables, carrots and liver.
 Uses: Maintains the health of the epithelium and acts
on the retina's dark adaptation mechanism.
 Deficiency leads to: Keratinisation of the nasal and
respiratory passage epithelium, night blindness

7. Retinol Retinoic Acid

8. Vitamin A
 It plays an important role in the formation and
maintenance of healthy skin, hair, and mucous
membranes. Vitamin A also helps us to see in dim light
and is necessary for proper bone growth, tooth
development, and reproduction.
 Vitamin A, also called Retinol, plays an important role in
cell division and gene expression. Also, the eyes and
mucous membranes of the mouth, nose, throat and lungs
depend on vitamin A to remain moist.
 Beta-carotene, an antioxidant that the body converts to
vitamin A. Beta-carotene, or provitamin A, comes from
fruits and vegetables.

9. Vitamin D (fat-soluble)
 Sources: Fish liver oils,egg yolks, dairy produce.
Vitamin D is formed in the skin when it is exposed to
sunlight
 Uses: Has a role in the absorption of calcium, which is
essential for the maintenance of healthy bones. It's
also great for forming strong teeth.
 Deficiency leads to: Rickets

10. Vitamin D
 Vitamin D plays a critical role in the body’s use of calcium and
phosphorous. It increases the amount of calcium absorbed from the
small intestine and helps form and maintain bones. Children especially
need adequate amounts of vitamin D to develop strong bones and
healthy teeth.
 Vitamin D, also called Calciferol, is a vitamin that dissolves in the
body's fat. Vitamin D is found in food, but also can be made in your
body after exposure to ultraviolet rays from the sun. There are several
different forms of vitamin D. Each form has a different activity.
 Vitamin D is a steroid hormone that functions to regulate specific gene
expression following interaction with its intracellular receptor. The
biologically active form of the hormone is 1,25-dihydroxy vitamin
D3 (1,25-(OH)2D3, also termed calcitriol). Calcitriol functions primarily
to regulate calcium and phosphorous homeostasis.

11. Vitamin E (fat-soluble)
 Sources: Pure vegetable oils; wheatgerm, wholemeal
bread and cereals, egg yoke, nuts sunflower seeds
 Uses: Protects tissues against damage; promotes
normal growth and development; helps in normal red
blood cell formation
 Deficiency leads to: May cause muscular dystrophy

12. Vitamin E (α-tocopherol)

13. Vitamin E
 Vitamin E acts as an antioxidant, protecting vitamins A and C, red blood cells and
essential fatty acids from destruction. Research from a decade ago suggested that taking
antioxidant supplements, vitamin E in particular, might help prevent heart disease and
cancer
 Vitamin E does a lot of things. It is believed that vitamin E may also prevent blood cells
from sticking to each other and to the blood vessels they travel. This will help promote
clear and flexible blood vessels and lower blood pressure. Vitamin E is absorbed from the
intestines packaged in chylomicrons. It is delivered to the tissues via chylomicron
transport and then to the liver through chylomicron remnant uptake. The liver can
export vitamin E in VLDLs. Due to its lipophilic nature, vitamin E accumulates in cellular
membranes, fat deposits and other circulating lipoproteins. The major site of vitamin E
storage is in adipose tissue.
 The major function of vitamin E is to act as a natural antioxidant by scavenging free
radicals and molecular oxygen. In particular vitamin E is important for preventing
peroxidation of polyunsaturated membrane fatty acids. The vitamins E and C are
interrelated in their antioxidant capabilities. Active α-tocopherol can be regenerated by
interaction with vitamin C following scavenge of a peroxy free radical. Alternatively, α-
tocopherol can scavenge two peroxy free radicals and then be conjugated to glucuronate
for excretion in the bile.

14. Vitamin K (fat-soluble)
 Sources: Green vegetables
 Uses: Used by the liver for the formation of
prothrombin
 Deficiency leads to: Bleeding due to delayed clotting
times caused by lack of clotting factors. Patients may
show signs of bruising easily and have nosebleeds.

15. Vitamin K
 Naturally produced by the bacteria in the intestines,
vitamin K plays an essential role in normal blood
clotting and helps promote bone health.
 The major function of the K vitamins is in the
maintenance of normal levels of the blood
clotting proteins, factors II, VII, IX, X and protein C
and protein S, which are synthesized in the liver as
inactive precursor proteins.

16. Water-soluble Vitamin
 A water-soluble vitamin is a vitamin that dissolves in
water. Vitamin C and Vitamin B are water soluble
vitamins. Water-soluble vitamins cannot be stored in
the body for long periods of time. Water-soluble
vitamins travel through your body and the whatever
your body doesn't need, comes out in your urine.
These kinds of vitamins need to be replaced daily.

17. Vitamin B1 (thiamine) (water-soluble)
 Sources: Yeast, egg yolk, liver, wheatgerm, nuts, red
meat and cereals
 Uses: Carbohydrate metabolism
 Deficiency leads to: Fatigue, irritability, loss of
appetite; severe deficiency can lead to beri-beri

18. Vitamin B1 (Thiamin)
 Thiamin (also written thiamine) is also known as
vitamin B1 . Thiamin is derived from a substituted
pyrimidine and a thiazole which are coupled by a
methylene bridge. Thiamin is rapidly converted to its
active form, thiamin pyrophosphate, TPP, in the brain
and liver by a specific enzyme, thiamin
diphosphotransferase.

19. Thiamin Structure

20. Thiamin Pyrophosphate (TPP)
 TPP is necessary as a cofactor for the pyruvate
dehydrogenase and α-ketoglutarate dehydrogenase
catalyzed reactions as well as the transketolase
catalyzed reactions of the pentose phosphate
pathway.
 The dietary requirement for thiamin is proportional to
the caloric intake of the diet and ranges from 1.0–1.5
mg/day for normal adults. If the carbohydrate content
of the diet is excessive then an increase in thiamin
intake will be required.

21. Vitamin B2 (riboflavin) (water-soluble)
 Sources: Dairy products, liver, vegetables, eggs,
cereals, fruit, yeast
 Uses: Intracellular metabolism
 Deficiency leads to: Painful tongue and fissures to
the corners of the mouth, chapped lips

22. Riboflavin

23. Riboflavin
 Riboflavin is also known as vitamin B2. Riboflavin is
the precursor for the coenzymes, flavin
mononucleotide (FMN) and flavin adenine
dinucleotide (FAD). The enzymes that require FMN
or FAD as cofactors are termed flavoproteins.
Several flavoproteins also contain metal ions and are
termed metalloflavoproteins. The normal daily
requirement for riboflavin is 1.2–1.7 mg/day for
normal adults.

24. Vitamin B12 (water-soluble)
 Sources: Liver, red meat, dairy products and fish
 Uses: Essential for manufacturing of genetic material
in cells. Involved in the production of erythrocytes
 Deficiency leads to: pernicious anemia

25. Cobalamin

26. Cobalamin
 Cobalamin is more commonly known as vitamin B12.
Vitamin B12 is synthesized exclusively by
microorganisms and is found in the liver of animals
bound to protein as methycobalamin or 5'-
deoxyadenosylcobalamin. The vitamin must be
hydrolyzed from protein in order to be active.
Hydrolysis occurs in the stomach by gastric acids or
the intestines by trypsin digestion following
consumption of animal meat.

27. Vitamin C (ascorbic acid) (water-soluble)
 Sources: Green vegetables and fruit
 Uses: Essential for the maintenance of bones, teeth
and gums, ligaments and blood vessels. It is also
necessary for ensuring a normal immune response to
infection
 Deficiency leads to: Scurvy

28. Ascorbic Acid

29. Ascorbic Acid
 Ascorbic acid is more commonly known as vitamin C.
Ascorbic acid is derived from glucose via the uronic acid
pathway.
 The active form of vitamin C is ascorbic acid itself. The
main function of ascorbate is as a reducing agent in a
number of different reactions. is the hydroxylation of
proline residues in collagen. Vitamin C is, therefore,
required for the maintenance of normal connective tissue
as well as for wound healing since synthesis of connective
tissue is the first event in wound tissue remodeling.
Vitamin C also is necessary for bone remodeling due to the
presence of collagen in the organic matrix of bones.