Association of 25-hydroxy vitamin D with asthma and its severity in children: a case–control study

Abstract

Background Universally, asthma has high prevalence rates and this has led numerous studies done into its causes. Despite extensive study on asthma the association between 25-Hydroxy Vitamin D (25(OH) vit. D) and asthma remains uncertain. In this study, the associations of 25(OH) vit. D levels with asthma and with the severity of asthma were evaluated. Methods This was a case–control study performed in 2015 in the city of Isfahan. In this study 520 children were studied. Children with asthma were classified as cases and children who were referred for reasons other than respiratory problems and asthma were considered as controls. Serum 25 (OH) vit. D levels were then examined and compared between the two groups. Differences among groups were stated to be statistically significant when P-values < 0.05. Results There were 260 asthmatic children and 260 controls in the present study. The mean 25 (OH) vit. D levels in the case group was 25.5 ± 16.62 and 16.76 ± 31.40 the control group and this difference was statistically significant (P < 0.05). 25(OH) vit. D levels were found to be 28.05 ± 16.98 in non-severe asthma and 21.41 ± 15.20 in severe asthma. Consequently 25(OH) vit. D level had inverse relationship with asthma severity (P = 0.002). Conclusions As the results of this study showed, the lower level of 25(OH) vit. D correlated with the higher severity of asthma manifestations. Therefore, it is recommended that 25(OH) vit. D levels get routinely checked especially in severe asthma cases and if the deficiency presents, appropriate therapeutic measures be used to reduce the asthma severity.

Genetic Diversity in Bronchial Asthma Susceptibility: Exploring the Role of Vitamin D Receptor Gene Polymorphisms in Varied Geographic Contexts

“…Diet was not considered in our study but may have been critical in maintaining vitamin D balance in this case. Various case-control studies have found differences in vitamin D levels between patients with asthma and healthy controls, particularly decreased vitamin D levels in a cohort of patients with asthma [51,52]. In the LT population, the mean 25(OH)D level was significantly elevated in the controls compared to the patients with BA group (p < 0.0001) and differed between the groups stratified by deficiency and sufficiency (p < 0.0001).…”

Asthma and Vitamin D Deficiency: Occurrence, Immune Mechanisms, and New Perspectives

“…The level of vitamin D in the serum was not in associated with the severity of asthma in some studies [32]. However, there have also been reports of correlation between the vitamin D level and asthma severity in contrast [14,33].…”

“…Vitamin D might play a role in asthma pathogenesis by affecting the development of the lungs, regulating the immune responses and remodeling of airway smooth muscle (ASM) [13]. The lower levels might be associated with severe forms and more severe manifestations [14].…”

Vitamin D [Serum 25(OH) cholecalciferol] Insufficiency is Associated With Childhood Asthma: Recent Case-Control Findings From Bangladesh

“…The study design (case-control) that we followed to conduct this study remains like many others. This design was used in similar studies looking into the relationship between Vitamin D and asthma, conducted in Qatar, 5 USA, 10 Egypt, 11 Iran, 12 - 14 and India. 15 , 16 Age of both asthmatic (n = 87: cases) and non-asthmatic (n = 90: controls) ranged between 2 and 12 years, with a mean age of 6.05 ±2.05 in cases and 6.75±3.09 in controls which remains consistent to other studies in Iran, 12 , 14 India, 15 , 16 Turkey, 17 Israel, 18 USA, 10 and Bangladesh, 6 though we purposively excluded <2 years-old children since they reportedly suffer more from bronchiolitis as reported by Hassan et al 2 Bangladesh.…”