Serum levels of vitamin A and 25-hydroxyvitamin D3 (25OHD3) as reflectors of pulmonary function and quality of life (QOL) in children with stable asthma: A case–control study

BACKGROUND: This study aims to explore the relationship between serum vitamin A and 25-hydroxyvitamin D3 (25OHD3) levels with pulmonary function and quality of life (QOL) in children with stable asthma. METHODS: A total of 117 cases of children with stable asthma were assigned into the case group and 129 healthy children underwent physical examination during the same period into the control group. Electrochemiluminescence was employed to determine serum vitamin A and 25OHD3 levels. The children with stable asthma were further divided into the mild, moderate, and severe groups according to their degree of asthma. A pulmonary function meter was used to assess the pulmonary function indexes: percentage of forced expiratory volume in 1 sec/predictive value (FEV(1)%pred), forced vital capacity (FVC), forced expiratory volume in 1 sec/forced vital capacity (FEV(1)/FVC), peak expiratory flow (PEF), and maximal voluntary ventilation (MVV). The children's quality (QOL) of life with asthma was evaluated by their activities of daily living (ADLs) and Medical Research Council (MRC) scores. Pearson correlation analysis was applied to analyze the correlations of serum vitamin A and 25OHD3 levels with FEV(1)%pred, FVC, FEV(1)/FVC, PEF, MVV, ADL, and MRC. RESULTS: Serum vitamin A and 25OHD3 levels were lower in children with stable asthma than those who were in the control group (P < .05). The severe group showed the lowest FEV(1)%pred, FVC, FEV(1)/FVC, PEF, MVV, and ADL scores, and the highest MRC score compared to the mild and moderate groups (all P < .05). Serum vitamin A and 25OHD3 levels were positively correlated with pulmonary function and ADL score in children with stable asthma, while serum vitamin A and 25OHD3 levels were negatively correlated with MRC score (all P < .05). In the case group, serum vitamin A and 25OHD3 levels were positively correlated with serum calcium and phosphorus levels (all P < .05). CONCLUSION: These findings indicate that increased serum vitamin A and 25OHD3 levels reflect good pulmonary function and good QOL in children with stable asthma.