Correlation between serum vitamin D status and childhood asthma: An analytical study from Eastern India

Background: Epidemiological studies determining the influence of vitamin D status on childhood asthma remain inconclusive and data are scarce from eastern India.
Objectives: To evaluate the serum vitamin D status in children with asthma and investigate its association with disease control
Method: This cross-sectional analytical study included 90 asthmatics and 90 healthy children, aged 5-12 years over one year. Serum 25-hydroxyvitamin D was measured via a chemiluminescence method. Univariate and multivariate analyses were performed to investigate the risk factors for childhood asthma and its level of control. Pearson correlation analysis was applied to identify the correlation between serum vitamin D concentration and spirometry parameters.
Results: The proportion of vitamin D deficiency and insufficiency among asthmatics and healthy children was 32.2% vs 14.4% and 41.1% vs 31.1%, respectively (p<0.001). Mean serum vitamin D level was significantly low in children with uncontrolled asthma (12.59±3.56 ng/mL) compared to those with partially (25.05±5.32 ng/mL) or well-controlled (25.54±5.49 ng/mL) diseases. In multivariate analysis, vitamin D deficiency (AOR: 4.37, 95% CI: 2.31–5.63) and family history of asthma (AOR:2.35, 95% CI:1.33–3.99) were found to be statistically significant predictors of childhood asthma. The FEV1 and PEFR were positively correlated with serum vitamin D levels.
Conclusions: There was a high prevalence of vitamin D deficiency/ insufficiency in Eastern Indian children with asthma. Vitamin D deficiency was also associated with an increased risk of childhood asthma as well as its level of control.