1. Vitamin A and Vitamin A
Deficiency Disorders
Dr. Moumita Pal
MBBS,DPH, MD
Dept. of Community Medicine
College of Medicine and Sagore Dutta Hospital
2. Vitamin A
• Active form-Retinol
• Proactive form (precursor)-Carotinoids
• Fat soluble
• Stable to heat at ordinary cooking
temperature.
• IU of Vit.A =0.3 mcg of Retinol
• RE: Retinol equivalent (Vit A activity)
• 1mcg of retinol=1 RE=3.33IU Vit A
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3. Functions
• Formation of rhodopsin in Rods of retina. Helps
in dark adaptation
• Integrity of cellular structures specially
epithelial tissue ( respiratory, GI tract, GU tract,
skin)
• Role in immune defense mechanism
• Antioxidant property of free radical scavenging
• Skeletal growth
• Protects against certain cancers like bronchial
cancers 3
4. Sources
1. Animal Foods (retinol) : Liver, meat, kidney,
milk, fish, eggs. Richest source is fish liver oil.
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5. Sources
2. Plant foods ( carotenoids):
coloured fruits and vegetables.
- green leafy vegetables (
spinach, amaranth)
-yellow orange vegetable and
fruits( pumpkin, mango,
papaya, apricots, carrots)
- Carotene converted to Vit A in
small intestine.
- Pigments with no vit A activity:
Lycopene in tomatoes
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6. • Vit E protects it from oxidation
Destroyed by
• exposure to sunlight
• Heating for a long time
• Drying and dehydration
3. Fortified foods: vanaspati
margarine, milk
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7. Storage
• Liver
• Retinol palmitate mostly
• Well fed person has sufficient reserve for 6-9
months
• Retinol ( free) highly toxic. Transported in
blood with retinol binding protein ( produced
in liver)
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8. Requirements and recommendations
Groups Retinol RDA (mcg)
Adults ( Male/female)
Children >6 years
Adolescents
600
Children (1-6 years) 400
Infants (<12 months) 350
Pregnancy 800
Lactation 950
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9. Toxicity
• Induced by single dose of >200mg ( 200000RE)
• Chronic - >4000 RE (infants) to 7000 RE (adults) consumed
daily
• Persistent large dose > 100 times of required dose daily
overwhelm liver storage capacity and produced
intoxication
• Skin/mucous membrane changes
• Dry lips, dryness of nasal mucosa and eyes, erythema,
scaling, peeling of skin, hair loss and nail fragility
• Headache, nausea vomiting
• Toxic to fetus (teratogenic): craniofacial, CNS,
cardiovascular, thymic malformation
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11. Signs and symptoms
Dryness, itching and redness of conjunctiva
Night blindness ( inability to see in dim light)
Others signs of xerophthalmia: Bitot spots, corneal xerosis, keratomalasia
Dry rough itchy skin: rash
Dry brittle hair and nail
Loss of acuity of senses : smell and taste
Loss of appetite
Fatigue
Poor growth
Low immunity/ vulnerability to infections
Increased risk of certain cancers
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12. Vitamin A deficiency
• Leading cause of preventable blindness in
children
• Major cause of controllable public health and
nutrition problem in India
• 5.7 % children of India suffer from s/s
• Only 21 % children (12-35months age)
received Vit A supplementation
• Less than 10% coverage in Nagaland & UP
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13. Etiological factors
• Most common in 1-3 years age group
Weaning and infections:
• Mothers not conversant with correct weaning practices
• Low vit A diet: diluted milk, poor starchy food, no fruits,
butter, vegetables or animal food
• Ignorance and economic reasons
• Repeated infection during teething, weaning, exposure
to the outer world high demand
• PEM immunologically vulnerable
• High rate of diarrhoea, respiratory infections measles
compromised Vit A status
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14. Social factors
• Cultural belief on BF and weaning
• Discarding colostrum, early or late weaning,
restrictions of food items, excessive dilution of
milk, vegetarianism, unscientific management
of infection, belief in quacks
• Poverty
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15. Poor environmental sanitation Practices:
• Non availability of sanitary latrines
• Open air defecation
• Poor hygienic practices
• Lack of potable water
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17. Xerophthalmia
• DEFINITION: “an abnormal dryness of the
eyeball produced usually by Long-continued
inflammation and subsequent atrophy of the
Conjunctiva and cornea.”
• Ocular manifestation of Vit A deficiency in
various clinical forms
• Leads to blindness
but preventable
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18. Xerophthalmia as a public health problem
WHO classification Clinical condition Prevalence among pre
school children
XN Night blindness >1%
X1A Conjunctival xerosis -
X1B Bitot’s spot >0.5%
X2 Corneal xerosis -
X3A Corneal ulceration/Keratomalacia (involving
<1/3 of cornea)
>0.01%
X3B Corneal ulceration/Keratomalacia (involving
>1/3 of cornea)
>0.01%
XS Corneal scar >0.05%
XF Xerophthalmic fundus -
Bio chemical Plasma retinol <0.35 micro mol/L >5% 18
19. Night blindness
• First symptom
• Inability to see in dim light
• Due to impaired dark adaptation
• Can be diagnosed by mother when- in the
evening child strikes against a stone and
while play and fall down/ unable to see the
content of food plate and gropes for food/ in
a dimly lit classroom can’t see blackboard
• Reversible with Vit A
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20. Conjunctival Xerosis
• First clinical sign
• Cornea and tissue of the eye
become dry , wrinkled
(vertically folded) and
thickened
• Restricted to “exposed”
bulbar conjunctive
• Dryness looks like waxy paint
as lose of transparency and
shiny appearance
• loss of goblet cells /Less
mucin production Un
wettable cornea 20
21. Bitot’s Spot
• Triangular pearly
white/yellowish foamy spots
on bulbar conjunctiva
• Either side of cornea
• Due to hyper-keratinizing
metaplasia of epithelium &
accumulations of
seborrhoeic excretions.
• Diagnostic in children but
adult- inactive sequelae of
earlier disease. 21
22. Corneal xerosis
• Cornea appears dry dull and non wettable
• Serious condition
• May progress to corneal ulceration
• Ulcer may heal leaving a scar behind
• Affect vision
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23. Keratomalacia
• Liquefaction of cornea
• Grave medical emergency-process is rapid
• Cornea becomes soft and burst open
• Through this content of eye may extrude out
• Eye collapses & vision lost
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24. Extra ocular manifestations
• Follicular hyperkeratosis
• Growth retardation
• Anorexia
• Non specific & difficult to quantify
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25. Treatment schedule for xerophthalmia
for all age groups except women of
reproductive age
Timing Vit A dosage
Immediately on diagnosis (day 1)
-<6 months of age
-6-12 months
->12 months
-50000 IU
-100000IU
-200000IU (110 mg)
Next day ( day 2) Same age specific dose
At least 2 weeks later Same age specific dose
Vit A in oil/ Retinol Palmitate
http://apps.who.int/iris/bitstream/10665/41947/1/9241545062.pdf
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26. Women of reproductive age
• Daily oral dose of 5000-10000IU for 4 weeks
• Such daily dose should never exceed 10000IU
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28. XEROPHATHALMIA FUNDUS:
• Pale yellow spots near the course of the
retinal vessels and in the retinal periphery
• Disappear with 2- 4 months of vitamin A
therapy
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30. Prevention
1. Dietary modification
• Vit A or beta carotene rich food
2. Nutrition education
• Importance of vitamin rich diet, regular intake,
harmful effects of deficiency
• Fresh seasonal fruits and vegetables
• Healthy food preservation techniques
• Public meeting, schools and Mass media may be
used
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31. 3. Fortification
• Ghee, dalda, butter, margarine, dried skimmed milk
etc.
4. Periodic massive dosage
• NIS
• First dose- 100000 IU at 9th completed months along
with measles vaccine
• Then 200000IU at 16 months with DPT/OPV booster.
• Then same dose at 6 months interval up-to 5 years
• Total 9 mega-doses
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32. 5. Long term actions
• Continuous nutritional education
• Importance of immunization
• Environmental sanitation
• Breast feeding
• Early treatment of infection
• Good maternal and child health care
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