Hypovitaminosis A

Hypovitaminosis A results from inadequate intake of vitamin A, fat malabsorption, or liver disorders and produces a variety of epithelial alterations.

Epidemiology

The World Health Organizatiοn currently estimates that 45-122 countries have a vitamin A deficiency of public health significance based on the prevalence of night blindness and biochemical vitamin A deficiency (serum retinol concentration <0.70 µmol/L), respectively, in preschool-age children.

Night blindness is estimated to affect 5.2 million preschool-age children (33.3% globally) and 9.8 million pregnant women (15.3% globally). Regions of Africa and South-East Asia were found to be the most affected.

Clinical presentation

Manifestations include:

• dry and scaly skin

• increased intracranial pressure

• ocular effects

  • xerophthalmia (dry eye) - common cause of blindness in young children in developing countries

  • poor night vision/night blindness

  • photophobia

  • Bitot spots

• skull hyperostosis ⁵

  • can lead to secondary compressive optic neuropathy ⁵

• decreased immunity

• renal tract stones from pelvic keratinisation

• in infancy

  • susceptibility to infection

  • anaemia

  • cranial nerve injury

  • growth retardation

Radiographic features

• slow bone development

• widening of the cranial sutures with bulging fontanelles

• skull hyperostosis ⁵

Treatment and prognosis

Administration of vitamin A given orally or parenterally, if malabsorption is the cause of the deficiency.

See also

• vitamin A excess