Effect of vitamin D supplementation on asthma control in patients with vitamin D deficiency: the ACVID randomised clinical trial.

BACKGROUND: The relationship between asthma and vitamin D deficiency has been known for some time. However, interventional studies conducted in this regard have shown conflicting results. OBJECTIVE: To evaluate the efficacy of vitamin D supplementation in asthmatic patients in improving the degree of control of asthma. METHODS: Randomised, triple-blind, placebo-controlled, parallel-group study in adult asthmatic patients with serum 25-hydroxyvitamin-D3 <30 ng/mL. The intervention group received oral supplementation with 16 000 IU of calcifediol per week, and the control group had placebo added to their usual asthma treatment. The study period was 6 months. The primary endpoint was the degree of asthma control as determined by the asthma control test (ACT). Secondary endpoints included quality of life measured using the mini Asthma Quality of Life Questionnaire, the number of asthma attacks, oral corticosteroid cycles, the dose of inhaled corticosteroids, number of emergency visits, unscheduled consultations with the primary care physician and hospitalisations for asthma. RESULTS: One hundred and twelve patients were randomised (mean age 55 years, with 87 (78%) being women). Of the 112 patients, 106 (95%) completed the trial. Half the patients (56) were assigned to the intervention group and the other half to the control group. A statistically significant clinical improvement was observed in the intervention group (+3.09) compared with the control group (-0.57) (difference 3.66 (95% CI 0.89 to 5.43); p<0.001) as measured using ACT scores. Among the secondary endpoints, a significant improvement in the quality of life was found in the intervention group (5.34), compared with the control group (4.64) (difference 0.7 (95% CI 0.15 to 1.25); p=0.01). CONCLUSION: Among adults with asthma and vitamin D deficiency, supplementation with weekly oral calcifediol compared with placebo improved asthma control over 6 months. Further research is needed to assess long-term efficacy and safety. TRIAL REGISTRATION NUMBER: NCT02805907.

Calcifediol for Use in Treatment of Respiratory Disease.

Calcifediol is the prohormone of the vitamin D endocrine system (VDES). It requires hydroxylation to move to 1,25(OH)2D3 or calcitriol, the active form that exerts its functions by activating the vitamin D receptor (VDR) that is expressed in many organs, including the lungs. Due to its rapid oral absorption and because it does not require first hepatic hydroxylation, it is a good option to replace the prevalent deficiency of vitamin D (25 hydroxyvitamin D; 25OHD), to which patients with respiratory pathologies are no strangers. Correcting 25OHD deficiency can decrease the risk of upper respiratory infections and thus improve asthma and COPD control. The same happens with other respiratory pathologies and, in particular, COVID-19. Calcifediol may be a good option for raising 25OHD serum levels quickly because the profile of inflammatory cytokines exhibited by patients with inflammatory respiratory diseases, such as asthma, COPD or COVID-19, can increase the degradation of the active metabolites of the VDES. The aim of this narrative revision is to report the current evidence on the role of calcifediol in main respiratory diseases. In conclusion, good 25OHD status may have beneficial effects on the clinical course of respiratory diseases, including COVID-19. This hypothesis should be confirmed in large, randomized trials. Otherwise, a rapid correction of 25(OH)D deficiency can be useful for patients with respiratory disease.