Objectives: Studies have suggested a significant link between vitamin
D status and asthma. We sought to determine the cutoff level of25
hydroxy (25-OH) vitamin D that is significantly linked to asthma
status in children. Methods: Our cross-sectional study comprised 90
asthmatic children, aged 2-18 years. They were evaluated clinically
and classified according to asthma severity and control. Asthma
control test (ACT) was performed in those aged above 4 years.
Pulmonary functions were performed in cooperative children (n=59).
Serum 25-OH vitamin D levels were measured by ELISA in all
patients. Results: The study comprised 52 boys (57.7%) and 38 girls
(42.3%) with mean age 7.03±4.36 years. Thirty-six patients (40%)
had mild asthma, 37 (41%) moderate asthma and 17 (19%) had
severe asthma. Forty-two patients (46.6%) had controlled asthma; 14
(15.6%) partially controlled and 34 (37.8%) had uncontrolled asthma.
ACT score ranged: 11-26, with mean score: 18.9 ± 4.3 SD. Serum 25-
OHvitamin D levels ranged between 2-48 ng/ml (mean± SD: 12.2 ± 9
ng/ml); levels were comparable among different grades of asthma
severity (f= 1.975, p=0.145), while the uncontrolled asthma group
showed the lowest levels (f=8.511, p <0.001). 25-OH vitamin D levels
correlated positively with ACT score (r= 0.369, p= <0.001) but not
with inhaled steroids doses or any of the pulmonary function
parameters. A level of 7.5 ng/ml was associated with partial/complete
uncontrol of asthma with 81 % sensitivity and 53 % specificity.
Conclusion: 25-OH vitamin D levels below 7.5 ng/ml are associated
with poor asthma status in children.