Association between vitamin A supplementation and stunting and anemia in socially vulnerable Brazilian children.

Purpose: Vitamin A is related to concentrations of insulin-like growth factor type 1, a protein produced in response to growth hormone, and to increased mobilization of body iron stores. Thus, vitamin A aids in increased hematopoiesis and may be useful in preventing stunting and anemia. This study aimed to identify the association between vitamin A supplementation from the National Vitamin A Supplementation Program instituted in Brazil and stunting and anemia in socially vulnerable Brazilian children.

Methods: This is a Cross-sectional population-based study. Children aged 6-59 months old, living in favelas of a capital city in the Northeast of Brazil, were included. Sociodemographic variables were collected. Vitamin A supplementation was also evaluated using the child's vaccination card information. Anthropometric and capillary hemoglobin evaluations were performed to identify the presence of stunting and anemia, respectively. The association analysis was performed using Poisson regression with robust variance estimation.

Results: 598 children participated in this study; 11.3% and 55.6% had stunting and anemia, respectively. As for vitamin A supplementation, 59.5% had taken at least one dose of the supplement,and 3.5% were on the complete supplementation scheme. In the adjusted association analysis, vitamin A supplementation decreased the likelihood of children having stunting and anemia by 8% (RP:0.86; 95% IC 0.86-0.98; p = 0.014) and 31% (RP:0.69; 95% IC 0.53-0.89; p = 0.004), respectively. Children who were fully supplemented were 58% (RP:0.42; 95% IC 0.24-0.77; p = 0.008) less likely to have anemia.

Conclusion: Thus, vitamin A supplementation is a protective tool against stunting and anemia in children living in a situation of social vulnerability.