Why Vitamin A is Given in Measles
Vitamin A supplementation reduces measles mortality and complications because measles depletes vitamin A stores and impairs immune defenses, making vitamin A the only evidence-based intervention proven to decrease death rates, particularly in children under 2 years. 1, 2
The Mechanism: Why Measles and Vitamin A Are Linked
Vitamin A functions as an "anti-infective" vitamin because many of the body's defenses against infection depend on adequate vitamin A supply, and measles can become severe in vitamin A-deficient children. 3
Measles infection actively depletes vitamin A stores through rapid destruction of epithelial surfaces, increasing the body's utilization and creating a functional deficiency even in previously adequate children. 4
The immune defect from vitamin A deficiency may result from alterations in lymphocyte membrane glycoproteins, adverse effects on helper T-cell function, and compromised epithelial tissue integrity. 4
The Evidence: Mortality and Morbidity Reduction
Two doses of 200,000 IU vitamin A reduce overall mortality by 64% (RR=0.36; 95% CI 0.14 to 0.82) compared to placebo in children with measles. 5
Pneumonia-specific mortality decreases by 67% (RR=0.33; 95% CI 0.08 to 0.92) with two-dose vitamin A supplementation. 5
Children under 2 years experience an 82% reduction in mortality risk (RR=0.18; 95% CI 0.03 to 0.61) when given two doses of vitamin A. 5, 6
Meta-analysis confirms vitamin A supplementation in hospitalized measles patients is highly protective against mortality (odds ratio 0.39; 95% CI 0.22 to 0.66; P=0.0004). 7
Standard Dosing Protocol
For all children with clinical measles:
- Children ≥12 months: 200,000 IU orally on day 1 3, 1, 2
- Children <12 months: 100,000 IU orally on day 1 3, 1, 2
- Adults: 200,000 IU orally (same as children ≥12 months) 1
For complicated measles (pneumonia, otitis, croup, diarrhea with dehydration, or neurological problems):
For eye symptoms of vitamin A deficiency (xerosis, Bitot's spots, keratomalacia, corneal ulceration):
- Day 1: 200,000 IU (100,000 IU if <12 months) 3, 1
- Day 2: 200,000 IU (100,000 IU if <12 months) 3, 1
- 1-4 weeks later: 200,000 IU (100,000 IU if <12 months) 3, 1
Additional Benefits Beyond Mortality
Croup incidence decreases by 47% (RR=0.53; 95% CI 0.29 to 0.89) with vitamin A supplementation. 5
Duration of diarrhea reduces by nearly 2 days (WMD -1.92; 95% CI -3.40 to -0.44). 5
Otitis media incidence drops by 74% (RR=0.26; 95% CI 0.05 to 0.92). 5
Hospital stay shortens significantly (mean 10 versus 13 days; P<0.001) and intensive care requirements decrease (4.3% versus 10.5%; P<0.001). 8
Critical Clinical Considerations
Do NOT withhold vitamin A if the child received it in the previous month for complicated measles or eye symptoms—these situations require immediate dosing regardless. 3
Undernutrition is a strong indication for vaccination, not a contraindication, and similarly should prompt aggressive vitamin A supplementation. 3
Fever, respiratory infection, and diarrhea are NOT contraindications for vitamin A administration in measles patients. 3
Water-based formulations show superior mortality reduction (81% reduction, RR=0.19) compared to oil-based preparations (48% reduction, RR=0.52), though both are beneficial. 5
Common Pitfalls to Avoid
Single-dose regimens (200,000 IU once) show no significant mortality benefit (RR=0.77; 95% CI 0.34 to 1.78), so the two-dose protocol is essential for complicated cases. 5
Do not delay vitamin A administration while waiting for laboratory confirmation of vitamin A deficiency—91% of measles patients have serum vitamin A <0.56 μmol/L at baseline. 6
Vitamin A supplementation is safe with no observed adverse effects in clinical trials, making the risk-benefit ratio overwhelmingly favorable. 8