The association of serum 25-OH vitamin D with asthma in Saudi adults

The study aimed to assess the differences and associations of serum 25(OH) D levels in Saudi adults with and without asthma. A total of 1070 Saudi adults aged 22 to 28 years (359 with known asthma and 711 matched nonasthmatic controls) were selected randomly from the Riyadh Cohort, Saudi Arabia. Serum 25(OH) D serum levels were measured. Asthma diagnosis was taken from questionnaires. In all participants, 359 (33.6%) were known asthmatic and 711 (66.5%) were nonasthmatic. The overall incidence of vitamin D deficiency (serum 25(OH) D <25 nmol/L) was 29.6% in controls and 35.6% in asthma group (P=.01). The asthma group have a significantly lower serum 25(OH) D than the control group (P=.01) but lost significance after adjusting for age, body mass index (BMI), and sex. Nonasthmatic and asthmatic females had a higher incidence of vitamin D deficiency (33% and 46%) than nonasthmatic and asthmatic males (17% and 33%). Vitamin D deficiency is significantly high among Saudi adults with asthma, but more so among women. Whether vitamin D deficiency exacerbates asthma attack remains to be proven in this population.