What is the recommended dosing for vitamin A (International Units) in patients with suspected vitamin A deficiency, considering factors such as age, liver disease, and malabsorption disorders?

Vitamin A Dosing for Suspected Deficiency

For adults with suspected vitamin A deficiency, initiate treatment with 10,000-25,000 IU oral vitamin A daily for 1-2 weeks, then recheck levels at 3 months and transition to maintenance dosing based on underlying risk factors. 1, 2

Age-Specific Treatment Dosing

Adults (≥18 years)

• Treatment dose: 10,000-25,000 IU oral vitamin A daily for 1-2 weeks when deficiency is clinically suspected based on symptoms (night blindness, dry eyes) or risk factors (malabsorption, dietary restriction) 1, 2
• Recheck vitamin A levels at 3 months after initiating treatment 1, 2
• Monitor for clinical improvement in night vision and other symptoms within 1-2 weeks 1, 2

Children with Clinical Deficiency (Xerophthalmia)

For children with eye signs of vitamin A deficiency (xerosis, Bitot's spots, keratomalacia, corneal ulceration), use the following emergency treatment schedule: 3

• Day 1: 200,000 IU oral vitamin A 3, 2
• Day 2: 200,000 IU oral vitamin A 3, 2
• 1-4 weeks later: 200,000 IU oral vitamin A 3, 2
• Infants <12 months: Use half doses (100,000 IU per dose) 3, 2

Children with Severe Malnutrition

• All children with severe malnutrition (weight-for-height Z-score <-3) should receive the full treatment schedule above, even without eye signs 3

Preventive Supplementation in High-Risk Populations

Children in Endemic Areas

• Children 12 months to 5 years: 200,000 IU every 3 months 3, 2
• Infants <12 months: 100,000 IU every 3 months (total 400,000 IU in first year) 3, 2
• Alternative if 3-month dosing impractical: 200,000 IU every 6 months 3

Postpartum Women

• 200,000 IU within 2 months of giving birth to provide adequate vitamin A in breast milk 3, 2
• If postpartum dosing not feasible: 100,000 IU during third trimester of pregnancy 3

Maintenance Dosing After Treatment

Standard Maintenance

• After initial 1-2 week treatment course: 6,000 IU daily as part of a multivitamin for patients with confirmed deficiency but no ongoing malabsorption 1, 4

Malabsorption Disorders

• Post-bariatric surgery (RYGB, BPD/DS): 10,000 IU daily long-term 3, 1, 4
• Start at 10,000 IU (3,000 μg) daily and adjust based on monitoring 3
• Consider water-miscible forms of vitamin A to improve absorption after malabsorptive procedures 3

High-Risk Populations Requiring Screening and Supplementation

Actively seek vitamin A deficiency in the following populations: 3

Liver Disease

• Chronic liver disease patients show high prevalence of deficiency, with severity correlating to disease progression 3
• Liver transplant candidates have 69.8% prevalence of deficiency 3
• Chronic alcohol consumption depletes liver stores despite potentially normal serum levels 3

Malabsorption Syndromes

• Short bowel syndrome, cystic fibrosis, celiac disease, chronic diarrhea all increase deficiency risk 3
• Fat malabsorption from any cause warrants screening and supplementation 3

Chronic Kidney Disease

• Do NOT routinely supplement in CKD - these patients often have elevated serum retinol levels 3
• Monitor regularly as liver stores can become depleted despite elevated serum levels 3

Administration Considerations

Optimizing Absorption

• Administer vitamin A with lipid-containing meals or lipid emulsion to optimize absorption 1, 4
• For parenteral nutrition, use light-protecting material as vitamin A is photosensitive 3, 4
• Avoid adsorption losses to infusion bags during IV administration 3

Special Populations

• Women of childbearing age: Exclude pregnancy or use beta-carotene form instead of retinol if pregnancy is possible 1, 4
• Upper limit for women of childbearing age is 10,000 IU daily 3, 4

Treatment Failure and Specialist Referral

If no response to oral treatment after 1-2 weeks, refer to specialist for: 1, 2

• Assessment of underlying causes of persistent deficiency 2
• Consideration of intramuscular vitamin A injections 1, 2
• Investigation for severe malabsorption or other complicating factors 2

Safety Thresholds and Toxicity

Acute Toxicity

• Occurs with >300,000 IU (adults) or >60,000 IU (children) within hours to days 3
• Symptoms: increased intracranial pressure, nausea, headaches, joint/bone pain 3

Chronic Toxicity

• Daily amounts >25,000 IU for >6 years or >100,000 IU for >6 months 3, 4
• Hepatotoxic effects occur above 14,000 mg/day for prolonged periods 3
• Upper limit set at 10,000 IU daily for women of childbearing age 3, 4

Treatment Dose Safety

• The recommended treatment dose of 10,000-25,000 IU for 1-2 weeks is safe for short-term use 1, 2
• No recognized treatment for vitamin A toxicity exists - stop supplementation if toxicity occurs 3

Common Pitfalls to Avoid

Underdosing

• Do not use prophylactic doses (6,000 IU daily) when deficiency is clinically suspected - this underdoses the patient and delays recovery 1
• Treatment requires 10,000-25,000 IU daily, not maintenance doses 1, 2

Prolonged High-Dose Use

• Avoid prolonged high-dose supplementation beyond 1-2 weeks without reassessment 1
• Transition to maintenance dosing after initial treatment course 1, 4

Pregnancy Risk

• Never give >10,000 IU daily to pregnant women or those who may become pregnant due to teratogenic effects 4, 5
• Use beta-carotene form for women of childbearing age when pregnancy cannot be excluded 1, 4

Drug Interactions

• Excessive vitamin A can exacerbate vitamin K deficiency and affect coagulation 4
• Monitor patients on anticoagulants more closely 4

Inappropriate Supplementation

• Do not routinely supplement patients with chronic kidney disease - they often have elevated serum levels despite potential total body deficiency 3, 4

Documentation

• Document all vitamin A doses on the child's growth record chart 3, 2
• Track clinical response and laboratory values for ongoing management 1, 2