Vitamin A deficiency can cause night blindness, impaired vision, and even blindness. It is caused by poor intake of vitamin A rich foods, poor nutritional status, intestinal parasites like measles, and malabsorption disorders. Clinical features range from mild conjunctival dryness to corneal ulceration and melting. Treatment involves high dose vitamin A supplements based on age and severity of symptoms. Both short term treatment of symptomatic cases and long term prevention through improved nutrition, immunization, and control of diseases like measles and diarrhea are needed to control vitamin A deficiency.

1. Vitamin A deficiency
disorder
Dr Meseret
Lectures for medical students

2. Vitamin A
Outlines
• Functions of vit. A
• Causes of vit. A deficiency
• Ophthalmic features of vit. A deficiency
• Management of vit. A deficiency
• Prevention of vit. A deficiency

3. Functions of vit A
• Formation of visual pigments –Rods
• Regulates cellular differentiation:
Embryonic
Epithelial (eg, conjunctival, tracts)
Immune stem cells
Hematopoietic
Osteoid (osteoblasts, -clasts)

4. Adequacy
• Bone growth
• Reproduction
• Embryogenesis
• Rod vision
• Cell differentiation
• Immunity
Deficinecy
• Growth retardation
• Dysfunction (M&F)
• Teratogenesis
• Night blindness
• Epithelial metaplasia
• Impaired innate & acquired
defensesy

5. Causes of vitamin A deficiency
• 1. Poor intake of vita
A rich food stuffs
• 2. PEM
• Malabsorption
disorders ex diarrhea
• Intestinal parasites
Associated Measles
infection compounds
the risk of corneal
ulcer and perforation
VADD Reflect a Gradient of
Health Consequences

6. Grading of Xerophthalmia
• XN –Night blindness
• X1A- conjunctival xerosis
• X1B –bitot’s spots
• X2 - corneal xerosis
• X3A - Corneal ulcer, less
than 1/3 of cornea
• X3B - Corneal ulcer, 1/3
or more of cornea
• XF – xerophthalmic
fundus
• XS - Corneal scar

7. Clinical feautres
• Conjunctival xerosis
• Loss of goblet cells
(mucin) &
keratinisation
• Squamous
metaplasia
• Improves after 2-4
days of treatment

8. Clinical feautres…
Foamy lesion (Bitot’s
spots)
usually temporal
Keratinisation &
corynebacteria xerosis
Takes 2.5 days to
disappear

9. Clinical feautres…
• X2: dry cornea
(corneal xerosis)
due to keratinisation
(reversible with
treatment)

10. Clinical feautres…
- In keratomalacia, the
cornea melts due to
stromal
necrosis.
- It can occur very
rapidly without
warning signs and
eye
ball may rapture.
- Young children (1-5
yrs) most affected

11. Clinical features…
• Coneal Opacity
Not treatable
Corneal blindess if it
is central

12. Clinical feautres…
• Xerophthalmic
fundus
• Multiple round,
whitish lesions in the
fundus

13. Control of VADD
Shot term measures
• Treat cases: 200,00iu stat the day 2 then after 4 weeks
(half the dose for children <1yr or <8Kg)
• Treat those at risk (prophylaxis): sick children (fever,
diarrhea, malnutrition etc) and pregnant/breast feeding

14. Treatment of xerophthalmia
Timing Malnutrition Measles Xerophth.
Infants and children:
- 0-5 months (50,000 IU)
- 6-11 months (100,000 IU)
- males >12 months (200,000
IU)
- females>12 mo-12 ys; >49 ys
Day 1
Day 1
Day 1
Day 1
Day 1, 2
Day 1, 2
Day 1, 2
Day 1, 2
Day 1,2 and 14
Day 1,2 and 14
Day 1,2 and 14
Day 1,2 and 14
200,000 day 1,2,14
Women (aged 13-49 years)
- XN and/or Bitots spot
- X3a or X3b (rare)
10,000 daily for 3 mo
or
25,000 weekly for 3
wks

15. Control of VAD
Mid term measures
• Measles immunization
• Fortify foods
• Control diarrhoeal diseases

16. Control of VAD
Long term measures
• Improve nutrition of mothers and children
• Kitchen gardens
• Nutrition health education
• NB. Macro and micro economic policies formulations.