Impact of rapid correction of vitamin D deficiency in asthmatic patients

Asthma is one of the most common chronic diseases, which is a growing public health concern worldwide. In recent years, there has been an increasing number of interests in the relationship between vitamin D level and asthma control. Hence, the objective of this study was to assess the effect of high doses of vitamin D₃ injection on asthmatic patient's respiratory condition and quality of life.

This was a single arm, before and after interventional study involving 18 patients with moderate to severe asthma. Spirometry test, St George's respiratory questionnaire (SGRQ) and serum vitamin D assay were performed. Subjects with 25-hydroxyvitamin D₃ (25-(OH) D₃) < 20 ng/ml were deemed deficient (n = 18) and received 2 intramuscular injections of vitamin D₃ 300,000 IU at monthly intervals consecutively.

The mean changes of forced expiratory volume in the first second (FEV1) were significantly different in subjects who received vitamin D₃ injections (p = 0.008). Also, the mean changes in FEV1/forced vital capacity ratio (FEV1/FVC) were significant (p < 0.001) as well as maximum expiratory flow between 25% and 75% of FVC (MEF25-75) (p = 0.001). Interestingly, improvement in clinical parameters of SGRQ was also observed with significant differences in total score (p = 0.001). Naturally, serum vitamin D levels were increased in our patients following the injections (p < 0.001).

Our findings suggest that screening for serum 25-(OH) D₃ deficiency is important in asthmatic patients and correction of this deficiency with high doses of vitamin D₃ injection may lead to improvement in pulmonary function, symptoms and quality of life (QOL).