Vitamin A deficiency in children aged 6 to 24 months in S~ao Paulo State, Brazil

Abstract

Vitamin A deficiency (VAD), mainly the subclinical form, is endemic in several areas of the Brazilian Northeast. However, studies concerning its prevalence and etiology (risk factors) in urban areas of São Paulo State are lacking. The objective of the present study was to identify VAD and the risk factors among children attending a Child Care outpatient clinic in Ribeirão Preto city, São Paulo State, Brazil. A total of 103 children aged 6 to 24 months without any diarrhea or fever illness were selected from a pediatric outpatient clinic. A careful clinical history and physical examination provided information about breast-feeding, parental education, family income, family size, birth weight and anthropometric data. The children also underwent ophthalmologic examination to check for signs of xerophthalmia and were submitted to blood tests in order to determine hemoglobin and serum iron, zinc and retinol levels. Serum retinol levels £ 0.70 μmol/l are considered to be deficient by the World Health Organization. Retinol levels, determined by high performance liquid chromatography (HPLC), were £? 0.70 μ?mol/l in 22 children (21.4%). No child had xerophthalmia. The overall mean serum zinc level was 108.9 μg% (2SD ± 43.1 μg%) and the values for children with and without VAD were 105.1 μg% (2SD ± 44.1 μg%) and 110.0 μg% (2SD ± 43.2 μg%) respectively, with no child presenting serum zinc levels below the normal range. None of them showed a <? -2 Z score for height/age or weight/height compared to reference values. No significant differences were observed between children with or without VAD concerning parental education, family income, family size and hemoglobin, or serum iron and zinc levels, but low birth weight (<? 2,500 g) was more frequent among children with VAD. Moreover, children without VAD were breast-fed for a significantly longer time than children with VAD (p<0.05). Children with VAD presented a history of low birth weight more frequently than children without VAD and breast-feeding was protective against VAD. This study showed that VAD is an important problem in children attending a Child Care outpatient clinic and that studies are needed in order to identify it and plan actions to combat it, mainly by encouraging breast-feeding practices.