ABSTRACT Objective To estimate the prevalence of vitamin A deficiency and determine the socioeconomic and demographic factors associated with serum retinol levels in public school students. Methods This cross-sectional study included 245 students from the urban and rural areas of the city of Teresina, Piauí, Brazil. Socioeconomic data were collected using a form. Serum retinol level was determined by high-performance liquid chromatography and classified according to the cut-off points provided by the World Health Organization. All statistical tests had a significance level of 5%. Results The prevalence of vitamin A deficiency (retinol level <0.70µmol/L) was 9.8% (95%CI=7.9-10.0). The prevalences of low and acceptable retinol levels (<1.05mol/L) were higher in students aged 12-14 years living in households without piped water supply (p>0.05). Water well or other untreated water sources were the factors most strongly associated with low retinol levels (OR=3.28; 95%CI=1.48-7.28; p=0.003). Conclusion Vitamin A deficiency was characterized as a mild public health problem in the students, indicating the need of actions that address this issue in schools and of studies with larger samples to investigate the problem at the municipal and state levels. Untreated water intake, a possible source of waterborne illnesses, contributed to lower retinol levels.

ABSTRACT Objective To estimate the prevalence of vitamin A deficiency and determine the socioeconomic and demographic factors associated with serum retinol levels in public school students. Methods This cross-sectional study included 245 students from the urban and rural areas of the city of Teresina, Piauí, Brazil. Socioeconomic data were collected using a form. Serum retinol level was determined by high-performance liquid chromatography and classified according to the cut-off points provided by the World Health Organization. All statistical tests had a significance level of 5%. Results The prevalence of vitamin A deficiency (retinol level <0.70µmol/L) was 9.8% (95%CI=7.9-10.0). The prevalences of low and acceptable retinol levels (<1.05mol/L) were higher in students aged 12-14 years living in households without piped water supply (p>0.05). Water well or other untreated water sources were the factors most strongly associated with low retinol levels (OR=3.28; 95%CI=1.48-7.28; p=0.003). Conclusion Vitamin A deficiency was characterized as a mild public health problem in the students, indicating the need of actions that address this issue in schools and of studies with larger samples to investigate the problem at the municipal and state levels. Untreated water intake, a possible source of waterborne illnesses, contributed to lower retinol levels.