The Effect of Vitamin D Levels on Asthma Exacerbation in Asthmatic Patients in a Tertiary Hospital: Retrospective...

Asthma is a major global health issue, affecting over 260 million individuals and causing more than 450,000 deaths annually. A growing body of international and local research has investigated the link between Vitamin D levels and asthma outcomes. These studies suggest that Vitamin D may play a role in modulating immune responses, potentially influencing asthma control, the frequency of exacerbations, hospital visits, and overall disease severity. However, evidence remains contradictory, where other studies did not establish a direct link between vitamin D levels and asthma development given the limited real-world data from Saudi Arabia.

This study aims to investigate the effect of serum Vitamin D levels and asthma exacerbations among adults, adolescents, and children within a Saudi population.

A single-center retrospective cohort study was conducted at the National Guard Hospital in Riyadh, Saudi Arabia, involving 379 asthma patients with documented Vitamin D deficiency within the past 6 to 12 months. The primary outcome was the effect of serum Vitamin D levels and asthma exacerbations. The secondary outcome is defining the correlation between Vitamin D levels and asthma severity.

A significant difference in asthma exacerbation frequency was observed between the Vitamin D-deficient and adequate groups during both the 6- and 12-month periods, with the adequate group experiencing more frequent exacerbations (p = 0.030). Furthermore, significant associations were found between Vitamin D levels and emergency room visits (p < 0.001), as well as the need for rescue medication (p = 0.004).

Interestingly, the results revealed that individuals with adequate vitamin D had a significantly higher frequency of exacerbations compared to those in the deficient group. These findings could be due to several confounding factors. Although vitamin D may contribute to overall respiratory health, its impact on severe asthma events may be overshadowed by other critical factors, such as Age and BMI, comorbidities, adherence to controller medications, and exposure to environmental triggers.