Efficacy of a single oral dose of 200,000 IU of oil-soluble vitamin A in measles-associated morbidity.

The authors assessed the efficacy of the World Health Organization (WHO) recommendation of 200,000 IU of vitamin A in oil to treat acute non-xerophthalmic measles patients. Acute measles patients who did not require hospitalization were enrolled in a randomized, double-masked, clinical trial of vitamin A (n=90) versus placebo (n=110) carried out in Ndola, Zambia, in 1991. Measles-associated morbidity was defined by the presence of signs and symptoms of acute respiratory infection. Daily evaluations for the first 3 days were followed by weekly visits for a month at urban health centers. Baseline demographic, clinical, and biochemical characteristics were similar in both groups. Cross-sectional analysis of morbidity status, by group, at each weekly evaluation showed no significant differences until week 4, when more placebo-treated patients had cough or pneumonia (p=0.005). However, longitudinal analysis, which looked at changes among individuals and controlled for initial health status, showed more equivocal results. The odds ratio for the development of pneumonia in patients with measles cough in vitamin A-treated subjects was 0.73 (95% confidence interval (Cl) 0.30-1.80). The odds ratio for the development of measles-associated cough or pneumonia in asymptomatic measles patients was 0.52 (95% Cl 0.24-1.13), in favor of vitamin A, but the odds ratio for failing to improve from pneumonia in vitamin A-treated subjects was 1.23 (95% Cl 0.68-2.3), a result in favor of placebo. These results suggest that the evidence for the efficacy of one dose of vitamin A in oil to prevent measles complications is not as strong as that previously shown for two 200,000 IU doses of water-miscible vitamin A, and that the WHO recommendation may need to be reexamined.