Effects of Vitamin A supplementation on child morbidity: A twenty-year time series analysis in the northeastern region of Brazil

Abstract

The present study aimed to determine the prevalence of supplementation between 1987 and 2007, and to measure the impact of this on morbidity. Five sequential cross-sectional studies in a 20-year time span were analyzed. Each had a sample of 8,000 domiciles representative of Ceará, in northeastern Brazil. Data were analyzed with descriptive statistics, followed by bivariate and multivariate analyses. Increases in coverage, ranging from 9.6 to 65.8 % were verified, and the study found that the impact of supplementation in reducing morbidity may not be significant. The study also found that supplementation may be associated with higher frequency of certain morbidities (OR 1.8, CI 95 % 1.20-2.95). When the supplementation variable was adjusted for socioeconomic factors, the risk was higher for diarrhea (OR 5.56, CI 95 % 2.63-11.75). The study concluded that in Brazil, vitamin A supplementation may have little benefit in reducing morbidity.

Interaction between vitamin A supplementation and chronic malnutrition on child development

“…It found a non-significant mortality rate reduction of 4%, (95% CI 0•89-1•03, p = 0•22), with no specific causes of mortality averted. Other evaluations of the effectiveness of supplementation have found contradictory results, depending largely on the presence of confounding conditions 22,25 . This can be attributed to the immunity modulator effect, or to subgroup effects of vitamin A (known as non-specific effects) 35 .…”

“…Supplementation at birth has tended to show a small positive effect on child development at three years of age 17 ; however this effect was not statistically significant, and when vitamin A was administered to very low birth weight babies, no effect was observed 18 . In animal models, it was found that the use of megadoses of vitamin A can lead to brain damage 19,20 , injury to motor functions 21 , and modulation of immunity 22 (effects associated with increased oxidative stress [19][20][21]23,24 ). In other studies, vitamin A supplementation has reduced morbidity and mortality in populations with a high prevalence of malnutrition 22,25 .…”