Clinical Nutrition

Lesson 6: Vitamin A Deficiency

Vitamin A deficiency and immunocompetence

Vitamin A deficiency is described as a nutritionally acquired immune deficiency disorder. It is characterised by

• Pathological alteration of the mucosal epithelium of the respiratory, gastrointestinal and genitourinary tracts.
  
  
• Impaired antibody responses to protein antigens
  
  
• Altered cell mediated immunity
  
  
• Alterations in T cells

Some of the genes relevant to immunity are regulated by vitamin A and vitamin A supplementation is associated with increase in circulating lymphocytes.