1. Dr. Thejaswini P.H
Dr. Thejaswini P.H
Associate Professor
Department of Biotechnology
Maharani’s Science College for Women
University of Mysore, Mysore, India
2. INTRODUCTION
Vitamins are organic substances that are essential for
carrying out the normal biochemical processes and
physiological functions of body.
These are non-energy compounds and required in
These are non-energy compounds and required in
very small quantities.
The vitamins generally serve as cofactors for the
enzymes required in intermediary metabolism.
Dr P.H Thejaswini, MSCWM 2
3. The main source of vitamins is diet.
• A balanced diet supplies adequate amounts of vitamins
to fulfill the daily requirements.
• Humans cannot synthesize vitamins in the body
except some vitamins such as Vit. D in skin, and
except some vitamins such as Vit. D in skin, and
Nicotinamide from tryptophan.
• Lack of particular vitamin leads to specific deficiency
syndromes. Vitamin deficiencies occur due to
inadequate intake, malabsorption, increased tissue
needs, increased excretion, certain genetic
abnormalities and drug-vitamin interactions.
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4. CLASSIFICATION
The vitamins have been broadly divided into two
groups:
Fat-soluble vitamins: vit. A, vit. D, vit. E and vit.-K.
These vitamins are stored by the body, mainly in the
These vitamins are stored by the body, mainly in the
liver. Excessive intake of these can lead to toxicity due
to accumulation, known as hypervitaminosis.
Water-soluble vitamins: vit B complex group, vit. C.
These vitamins are least stored and toxicity does not
occur. The excess of vitamins are rapidly metabolized
and readily excreted in the urine.
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5. The active forms of some of the
vitamins are as follows
Vitamins Active Forms Vitamin-A Retinal(Stored as Retinol)
Vitamin-D 1,25 Dihydrocholecalciferol
Vitamin- E α-Tocopherol
Vitamin- K Napthaquinone
Vitamin-C L- Ascorbic acid
Vitamin-C L- Ascorbic acid
Vitamin-B1 (Thiamine) Thiamine pyrophosphate
Vitamin-B2 (Riboflavin) Flavin-mononucleotide (FMN)
Vitamin-B3 (Niacin) Nicotinamide adenine dinucleotide (NAD)
Vitamin-B5 (Pantothenic acid) Coenzyme-A
Vitamin-B6 (Pyridoxine) Pyridoxal phosphate
Vitamin-B9 (Folic acid) Tetrahydrofolate
Vitamin-B12 (Cynocobalamine) 5-Methyl cobalamine
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6. FAT SOLUBLE VITAMINS
Vitamin- A
• There are various natural forms of Vitamin A
(vitamers) such as Retinol (vit A1), Dehydroretinol (vit
A2) and Carotenoids.
A2) and Carotenoids.
• Dietary Sources: Carrot (richest plant source), red
cabbage, turnip, spinach, mango etc. are some of the
plant sources. Marine fish liver oil such as cod, halibut
(richest animal source), fresh water fish, egg yolk,
milk, cheese, butter are some of the animal sources.
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8. Physiological functions
Essential for proper functioning of Rod cells in the visual
cycle; hence the night vision. Vision in the dim light
depends upon proper functioning of Rods. Prevents night
blindness and Xerophthalmia.
Maintenance of normal epithelium all over body.
Maintenance of normal epithelium all over body.
As antioxidants (vitamin-A,C,E are more potent
antioxidants in nature) and anti cancer properties.
Enhances immune functions and prevents recurrent
infections like measles, malaria and diarrhoea, etc.
In reproduction, for normal spermatogenesis and foetal
development.
Bone growth in children.
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9. Deficiency Symptoms
These are seen when there is a long term deprivation
and the stores are depleted. A disturbance in the
physiological roles manifests as the deficiency
symptoms. Some of the symptoms are:
symptoms. Some of the symptoms are:
Eye: Xerosis (dryness) of eye, ‘Bitot’s spots’,
keratomalacia (softening of cornea), corneal opacities,
night blindness (nyctalopia) progressing to total
blindness.
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10. Deficiency Symptoms
• Epithelium: Dry and rough skin with papules
(phrynoderma), hyperkeratinization, atrophy of sweat
glands, keratinization of bronchopulmonary
epithelium. Increased tendency to urinary stone
formation due to shedding of ureteric epithelial lining
formation due to shedding of ureteric epithelial lining
which acts as a nidus.
• Immunity: increased susceptibility to infection such as
diarrhoea, measles etc.
• Reproduction: Sterility due to faulty spermatogenesis,
abortions, foetal malformations and growth
retardation etc.
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12. Daily requirement and for prophylaxis of vit A
deficiency during infancy, pregnancy, lactation,
hepatobiliary diseases, steatorrhoea: 3000–5000
IU/day.
Recommended dietary allowance (RDA)
IU/day.
Treatment of established vit A deficiency: 50,000–
100,000 IU i.m or orally for 1–3 days followed by
intermittent supplemental doses.
Skin diseases like acne, psoriasis, ichthyosis. Retinoic
acid and 2nd or 3rd generation retinoids are used.
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13. Vitamin-A has been included in National Immunization
Programme of India.
A total 17-lac unit of vitamin-A is supplemented to
child.
A total of 9 mega doses are to be given from 9 months
of age to 5 years.
of age to 5 years.
100,000 IU at 9 months with measles immunization,
200,000 IU at 16-18 months with DPT booster,
200,000 IU every 6 months upto the age of 5 years.
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