Recurrent respiratory infections and vitamin A levels: a link? It is cross-sectional.

Respiratory tract infections are common illnesses in children, causing significant morbidity and negatively affecting their health. Vitamin A protects against infections and maintains epithelial integrity. The goal of this study was to determine the correlation between vitamin A deficiency and recurrent respiratory tract infections (RRTIs). Participants in this cross-sectional study were divided into 3 groups: RRTIs (including patients with history of RRTIs presenting with respiratory tract infection symptoms), RTI (including patients without history of RRTIs presenting with respiratory tract infection symptoms), and control (including children who came for a routine health checkup without a history of RRTIs or respiratory tract infection symptoms). The vitamin A assay was performed using high-performance liquid chromatography. The study included 550 children aged 6.64 ± 2.61 years. The RRTIs group included 150 children (27.3%), the RTI group included 300 children (54.5%), and the control group included 100 children (18.2%). Subclinical vitamin A deficiency and vitamin A deficiency affected 3.1% and 1.3% of subjects, respectively. Subclinical vitamin A deficiency and vitamin A deficiency were higher in children with RRTIs than in those with RTI (8% vs 1.3%, P = .001 and 4% vs 0.3%, P = .006). Additionally, children with RRTIs had significantly higher rates of subclinical vitamin A deficiency and vitamin A deficiency than those in the control group, which had 1% subclinical vitamin A deficiency (P = .017) and no cases of vitamin A deficiency (P = .043). The RRTIs group had higher rates of otitis media (27.3%), sinusitis (20%), and pneumonia (4.7%) than the RTI group (P = .002). Vitamin A insufficiency was associated with RRTIs in children.