A new insight into the immune regulatory functions of vitamin A in children and adolescents

Abstract

Background/Aim Vitamin A deficiency (VAD) is a serious and widespread public health problem. Vitamin A has an important role in regulating human immune function. It increases rates and severity of infections in young children mainly in developing countries. The present study aims to assess the effect of vitamin A on cluster of differentiation 4 (CD4) and thymosin β4 (Tβ4) levels as indicators of adaptive immunity. Moreover, we evaluate the association between serum vitamin A concentration and BMI among Egyptian children and adolescents.Patients and methods This cross-sectional survey was conducted on 46 apparently healthy participants, including 19 girls and 27 boys aged from 3 to 17 years. We assessed weight and height using standard techniques. Serum vitamin A, CD4, and Tβ4 concentrations were assessed by using enzyme-linked immunosorbent assay kits. We planned to divide the participants into vitamin A-sufficient and vitamin A-deficient groups according to its level.Results Cutoff for VAD was 44 μg/dl. It was detected in 56.6% of the enrolled participants. Vitamin A was significantly lower in teenagers comparative with children (P=0.04). Vitamin A and Tβ4 levels were significantly decreased in deficient group in comparison with sufficient one at P values of 0.002 and 0.017, respectively, whereas CD4 level was nonsignificantly decreased in vitamin A-deficient patients compared with the sufficient ones. A significant positive correlation was detected between vitamin A and both of CD4 (r=0.348, P=0.018) and Tβ4 (r=0.392, P=0.007). A significant positive correlation was found between vitamin A and BMI (r=0.311, P=0.035).Conclusion Vitamin A may influence Tβ4 and CD4 levels. This study is the first to explore the effect of vitamin A on Tβ4 level in children and adolescents and correlate it with CD4 level. This finding must be verified using large-scale studies.