What are the symptoms of vitamin A deficiency?

Symptoms of Vitamin A Deficiency

The primary symptoms of vitamin A deficiency include night blindness, increased susceptibility to respiratory infections, impaired intestinal immune and barrier function, and in severe cases, xerophthalmia which can progress to blindness. 1

Early Signs and Symptoms

• Night blindness (nyctalopia) - Often the earliest detectable functional sign due to insufficient rhodopsin synthesis 1, 2
• Increased susceptibility to infections - Particularly respiratory tract infections 1
• Impaired intestinal immune and barrier function 1
• Impaired growth - Especially in children 3
• Compromised immune response - Leading to higher morbidity from common infections 3, 4

Progressive Ocular Manifestations

As vitamin A deficiency worsens, the following eye symptoms may develop in sequence:

1. Conjunctival xerosis - Dryness of the conjunctiva 1, 2
2. Bitot spots - Gray/white, foamy appearances on the conjunctiva 1
3. Keratomalacia - Keratin deposits with spreading inflammation 1
4. Xerophthalmia - Maceration of the cornea 1
5. Secondary infection - Can lead to corneal ulceration 1
6. Blindness - The ultimate consequence of untreated severe deficiency 1, 4

Other Clinical Manifestations

• Follicular hyperkeratosis - Rough, dry skin with small bumps 1
• Poor bone growth - Affecting skeletal development 1
• Decreased resistance to infection - Making common illnesses more severe 1, 4

High-Risk Populations

Vitamin A deficiency should be actively sought in patients with:

• Liver disease - Especially chronic liver disease, with severity correlating with deficiency 1
• Chronic alcohol consumption - Results in depletion of vitamin A liver stores 1
• Liver transplantation candidates - Nearly 70% show deficiency 1
• Chronic kidney disease - Requires monitoring as levels can fluctuate 1
• Malabsorption conditions - Including:
  • Short bowel syndrome 1
  • Cystic fibrosis 1, 2
  • Celiac disease 1
  • Chronic diarrhea 1
• Obesity - Can affect retinol-RBP ratio 1
• Prolonged hypermetabolic conditions - Especially in patients on parenteral nutrition 1

Special Considerations

• Vitamin A deficiency is a significant public health problem in developing countries, particularly affecting children and pregnant women 1, 4, 5
• Clinical deficiency symptoms may be rare in developed countries but subclinical deficiency can still impact health 6
• Inflammation can decrease serum retinol concentrations, complicating assessment during acute infections 1
• Adolescents with cystic fibrosis are particularly susceptible to developing night blindness and conjunctival xerosis, especially if they have liver disease or don't take vitamin supplements 2

Diagnostic Considerations

• Serum retinol levels should be measured when investigating malabsorption 1
• Retinol levels may not correlate well with tissue concentrations and should not be assessed during acute infections 1
• Inflammation biomarkers (CRP, AGP) should be considered when interpreting vitamin A levels 1

Vitamin A deficiency remains a preventable cause of visual impairment, increased susceptibility to infections, and mortality, particularly in developing countries. Early recognition of symptoms and appropriate supplementation can prevent progression to severe manifestations and improve overall health outcomes.