This presentation discusses vitamin A deficiency. It begins by defining vitamins and describing the different types, including fat-soluble vitamins like vitamin A. Vitamin A plays important roles in vision, growth, immune function, and reproduction. Deficiency can cause night blindness, dry eyes, corneal ulceration and blindness. It is prevalent in developing nations and affects children's growth, immune function, and risk of infection. The presentation outlines signs and symptoms of deficiency, as well as measures to prevent and treat it, including dietary sources of vitamin A and supplements. It concludes by discussing toxicity which can damage the liver and bone health in high doses.

1. Presentation on vitamin A
deficiency
PRESENTED BY
MD. IRFANUR RAHMAN
BDS 3RD YEAR
DDC (D-54)

2. Vitamin
Vitamins are organic nutrients required in small
quantities for a variety of biochemical reactions to
support normal growth , maintenance and
reproduction.

3. Types of vitamins
Fat soluble vitamins
 Vitamin A
 Vitamin D
 Vitamin E
 Vitamin K
Water soluble vitamins
 Vitamin B complex
 Vitamin C

4. Vitamin A
 Chemical name:
 Retinol
 Retinal
 Retinoic acid
 Active form:
 Retinol
 Retinal
 Retinoic acid

5. Sources of Vitamin A

6. Functions of vitamin A
 Helps in vision by synthesizing visual pigments in
photoreceptors (rods and cones) of retina.
 promotion of growth and differentiation of tissue.
 Maintenance and differentiation of immune system cells,
epithelial cells and mucous secreting cells for providing
resistance to infection.
 Maintenance of reproduction

7. Metabolism and transport of vitamin A

8. Requirement of vitamin A
People with certain health conditions may need a higher
amount of vitamin A. In countries where vitamin A
deficiency is endemic, pregnant women should be
advised to eat dark-green, leafy vegetables and yellow
fruits and infants should fed the same. However, most
healthy adults need 700–900 mcg per day.

9. Deficiency of vitamin A
 Globally, the most important consequence of vitamin
A deficiency is irreversible blindness in young
children.
 Vitamin A deficiency is prevalent in developing
nations (Asia is notably affected) but rare in
developed nations.

10. Endemic areas of
vitamin A deficiency

11. Deficiency symptoms of vitamin A

12. Ocular Manifestations
 Night blindness (nyclatopia): It is the earliest symptom
caused by the interference of vision in dim light.
 Xeropthalmia : It occurs due to keratinization of lacrimal
glands and stoppage of tear secretion. Xeropthalmia is
characterized by-
 Dryness of conjunctiva and cornea.
 Keratinization of cornea
 Bilot’s spot

13.  Keratomalacia:
It is characterized by-
 softening of cornea.
 Photophobia
 Ulceration of cornea
 Fibrosis & scarring of cornea leading to blindness

14. Vulnerability to infection
Frequent infections, especially in the throat or chest, may
be a sign of vitamin A deficiency. Vitamin A supplements
may protect underweight children from infections but
increase the risk of infection in other groups. Adults with
high blood levels of vitamin A may experience fewer throat
and chest infections.

15. Dryness of skin
 Not getting enough vitamin A may be to blame for the
development of eczema and other skin problems.
 Xerosis and keratinization of skin happens due to
squamous metaplasia of epithelial cell.

16. Infertility and trouble conceiving
 Both men and women who do not get adequate
vitamin A can have fertility issues.
 Low vitamin A in parents may also lead to
miscarriages or birth defects.

17. Delayed growth
 Vitamin A deficiency can cause stunted growth in
children.
 Supplementing with vitamin A in combination with
other nutrients may improve growth

18. Biochemical assessment for vitamin A
deficiency
 Serum retinol : may be low in deficiency.
 Serum retinyl esterase: when vitamin A toxicity is
suspected.

19. Measures for
preventing vitamin A
deficiency

20.  According to WHO, single prophylactic oral doses of 60
mg retinyl palmitate should be given to pre-school children
of endemic areas.
 In endemic areas people should include meat, dairy and
eggs, as well as red, orange, yellow and green plant
foods, also small fishes in their daily diet.

21. Vitamin A Toxicity

22. Hypervitaminosis A or vitamin A toxicity typically results from
taking high-dose supplements over long periods of time and causes:
 Dry & pruritic skin
 Hepatomegaly
 Cirrhosis of liver
 Raised ICP
 Teratogenesis
 Decreased BMD (bone mineral density)
 Increased risk of bone fracture