Vitamin A deficiency among Brazilian school-aged children in a healthy child service

Abstract

Background/Objectives: Vitamin A deficiency (VAD) is a world public health problem contributing to the increase in childhood morbidity and mortality in developing countries and severe deficiency of vitamin A may lead to xerophthalmia and blindness. The objective of this study was to determine the prevalence of VAD among Brazilian school-aged children attended at a primary health unit and to verify if some considered risk factor was associated with VAD in this group. Subjects/Methods: A descriptive prospective transverse study was conducted on 103 randomly selected children. A total of 54 boys and 49 girls aged 5.5-11 years had the relative dose-response (RDR) test performed on. Possible ocular alterations related to vitamin A and the status of anemia, serum zinc, some acute-phase proteins, and anthropometric situation were determinate by an analytic design. Results: No child presented xerophthalmia. Serum retinol values lower than 1.05 and 0.7 mmol l À1 , respectively were found in 26.2 and 5.8% of the children. The prevalence of hypovitaminosis detected by RDR test was 20.4%. The following variables and their relationship with VAD were evaluated: sex (P ¼ 0.33; 95% confidence interval 0.61-4.34), weight and height (PX0.5), hemoglobin (P ¼ 0.15), C-reactive protein (P ¼ 0.56; 95% confidence interval 0.75-18.26), a-1-acid-glycoprotein (P ¼ 0.56; 95% confidence interval 0.15-15.42) and serum zinc (P ¼ 0.31). None of these variables was related to VAD. Conclusions: In this population, the prevalence of VAD detected could be considered a public health problem. School-aged children can be considered at risk for VAD mainly of a subclinical level, even without some associated risk factors.

Vitamin A deficiency and factors associated with retinol levels in public school students

“…Nevertheless, that frequency is lower than the percentages reported by nearly all studies on schoolers from other Brazilian regions [8][9][10][19][20][21]. Only Mariath et Table 2.…”

“…Serum retinol levels A B five to 18 years from a rural area of the Federal District by using HPLC, which is considered the gold standard, and defining inadequate serum retinol level as <20μg/dL (<0.07μmol/L); Custódio et al [9] found prevalences of 26.2% and 5.8% of serum retinol level <1.05μmol/L and <0.70μmol/L, respectively, in children aged five to 11 years by using the Relative DoseResponse method; and finally, more recently, Ribeiro-Silva et al [10] found a VAD prevalence of 27.8% in children and adolescents of a public school in Salvador (BA), by using a cut-off point of <30g/dL or <1.05μmol/L and HPLC.…”

“…Some Brazilian studies conducted in the last decade found that VAD also affects a considerable proportion of school-aged children and adolescents [8][9][10], groups that are not classically recognized as priorities regarding vulnerability to this deficiency. Nevertheless, the findings are justified by the fact that vitamin A is strongly involved in physical growth, which can be intense in children and adolescents undergoing a growth spurt, a period that requires more vitamin A [1,2,11] Additionally, children and adolescents are susceptible to cultural, social, and environmental influences, possibly promoting inappropriate eating habits and lower intake of dietary sources of vitamins and minerals [12] and contributing to the development of important deficiency-related conditions.…”

Brazilian studies on zinc deficiency and supplementation: emphasis on children

“…The quality criteria in which articles presented the greatest limitation were, in particular, proof of representativeness of the sample studied in relation to the study population (in observational and experimental studies); definition of main confounding factors (in observational studies) and description of loss of participant (in observational and experimental studies). Considering that all the articles had an average or high quality and that the main risks of bias were associated with the analysis of loss of participants and confounding factors, without negative effects on the objectives of the review, we decided to systematize all the studies The analysis of sample representativeness indicates that 15 studies 16,17,19,20,29,31,34,36,[38][39][40]42,[44][45][46] used a representative sample and random selection of participants, five 15,18,21,22,37 studied a large population percentage and ten 23,24,26,27,30,32,33,35,41,43 studied populations with no characteristic of representativeness. With the exception of two studies, 25,30 representativeness was guaranteed in all others that focused on preschool children (Tables 1 and 2).…”

“…15,[16][17][18][19][20][21][22][23]25,29,30 The Southeast Region concentrated most of the studies (n = 10), 18,19,[21][22][23][24][25][26][27]30 while the other regions had a maximum of four studies. The most commonly used biochemical indicators of zinc nutritional status were plasma zinc (n = 6), 15,18,24,27,28,30 serum zinc (n=5) 17,19,[21][22][23] and erythrocyte zinc (n = 3). 15,20,23 In order to evaluate dietary zinc intake, the 24-hour recall was the most commonly used instrument.…”