When to check vitamin A levels in patients with suspected vitamin A deficiency?

From the Guidelines

Vitamin A levels should be checked in patients with suspected vitamin A deficiency when there are clinical concerns, such as symptoms of deficiency or excess, or in individuals at high risk for abnormal levels. Signs of deficiency include night blindness, dry eyes, skin problems, frequent infections, and poor wound healing. Testing is recommended for those with malabsorption conditions (like celiac disease, Crohn's disease, or after bariatric surgery), chronic liver disease, cystic fibrosis, or those on long-term restrictive diets 1.

Key Indications for Testing

• Symptoms of deficiency, such as night blindness or protein malnutrition
• Malabsorptive procedures, such as BPD/DS, where routine monitoring of serum vitamin A levels is recommended 1
• Clinical concerns, such as deterioration in night vision, dry eyes, or protein–energy malnutrition 1

Testing and Monitoring

• The test involves a simple blood draw, typically performed after fasting, and measures serum retinol levels
• Regular monitoring may be necessary for those on vitamin A supplements or with chronic conditions affecting vitamin A status, as both deficiency and toxicity can have serious health consequences 1

Treatment and Referral

• For treatment of vitamin A deficiency in adults, oral supplementation with vitamin A, 10 000–25 000 IU d−1 for 1–2 weeks for clinical improvement is recommended 1
• Referral to a specialist should be considered if there are concerns about vitamin A deficiency or if the patient does not respond to treatment 1

From the Research

Vitamin A Deficiency Diagnosis

Vitamin A levels should be checked in patients with suspected vitamin A deficiency, particularly those with:

• Severe liver disease or other conditions causing malabsorption 2, 3
• Night blindness or loss of night vision 2, 3, 4, 5
• History of bile duct strictures after liver transplantation 3
• Malabsorption secondary to medical interventions, such as bowel resection or medication 4
• Cystic fibrosis, especially with abnormal liver function tests 5

Patient Profiles

Patients who may require vitamin A level checks include:

• Those with chronic, severe liver disease 2
• Post-orthotopic liver transplant patients with bile duct strictures 3
• Patients with a history of bariatric surgery, small bowel resection, or octreotide treatment 4
• Adolescents with cystic fibrosis, particularly those with liver disease or non-adherence to daily vitamin supplements 5

Diagnostic Criteria

Vitamin A deficiency can be diagnosed based on:

• Serum vitamin A levels below 20 micro g/dL (0.7 micro mol/L) 6
• Clinical symptoms, such as night blindness, conjunctival xerosis, or xerophthalmia 2, 3, 5, 6