Vitamin A deficiency can occur due to inadequate intake or impaired absorption of vitamin A. It leads to night blindness as vitamin A is essential for rhodopsin and visual pigments. Long term deficiency results in xerophthalmia and squamous metaplasia where respiratory and urinary tract linings are replaced by keratinizing squamous cells, increasing risk of infection. Oral manifestations include desquamation of oral mucosa, keratosis, increased risk of candidiasis, gingival hypertrophy and inflammation, leukoplakia, decreased taste sensitivity and xerostomia. Deficiency also impacts enamel and dentine formation, raising risk of cavities.

1. VITAMIN
DEFICIENCY
VITAMIN A - CHEMISTRY
RETINOL
RETINAL
RETINOIC
ACID

2. RDA(RECOMMENDED DAILY ALLOWANCE) -
MALE [ADULT] - 1000 ru/day
FEMALE (ADULT) -800 ru/day
PREFORMED
VITAMIN A
PRO VITAMIN

3. VITAMIN A - METABOLISM
SI
TRANSPORTABSORPTION
chylomicrons
STORAGE
LIVER
RBP

4. FUNCTIONS
VISION IN LOW LIGHT ANTIOXIDANT
DEVELOPMENT
OF TEETH &
SKELETAL TISSUE
EPITHELIAL CELL DIFFERENTIATION MAINLY
MUCUS SECRETING CELLS
ENHANCING
IMMUNITY

5. CAUSES ????
• Prolonged INADEQUATE INTAKE of vitamin A.
• IMPAIRED ABSORPTION. This may occur in a variety of
illnesses, including:
• Coeliac disease.
• Crohn's disease.
• Giardiasis - an infection of the gut (bowel).
• Cystic fibrosis-Diseases affecting the pancreas.
• Obstruction of the flow of bile from liver and gallbladder
into gut.

7. SQUAMOUS METAPLASIA
Vitamin A deficiency can lead to
replacement of lining of upper respiratory
passage & urinary tract by keratinizing
squamous cells.
Loss of mucociliary epithelium of the airway
predisposes affected patients to pulmonary
infection.

8. XEROPHTHALMIA

9. PRIMARY SIGNS ?????

10. NIGHT BLINDNESS
It’s a component of rhodopsin and other visual
pigments
WALD’S VISUAL CYCLE
Isomerization

11. ORAL MANIFESTATIONS
 Inadequate cell differentiation-impaired
healing & tissue regeneration;
 Desquamation of oral mucosa;
 keratosis;
 Increased risk of candidiasis;
 Gingival hypertrophy & inflammation;
 Leukoplakia;
 Decreased taste sensitivity;
 Xerostomia;

12. GINGIVAL
HYPERTROPHY
• Disturbed or arrested enamel
development;
• Irregular tubular dentine formation and
increased caries risk.
KERATOSIS

13. CANDIDIASAIS LEUKOPLAKIA

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