Asthmatic patients with vitamin D deficiency: Can vitamin D supplementation make a difference

Asthma is a major public health concern due to its persistent inflammation of the airways. The intricate and widely variable epidemiology of asthma among nations and populations is a result of the interplay between genetic, environmental, and socioeconomic factors.

This study aims to investigate whether VitD supplementation can reduce the frequency of exacerbations (including the frequency of exacerbations requiring systemic corticosteroids and the frequency of exacerbations necessitating trips to the hospital or emergency room, or both) and improve pulmonary function (clinical indicators such as the FEV1% predicted value).

Computers were used to search Pubmed, Medline, ISI Web of Science, Embase, Cachrane Library, CNKI, CBM, VIP, and the Wanfang Database. Asthma/asthma, VitD/VitD, lung function/lung function, retrieval time is from database setup to October 8, 2021, to search all randomized controlled trials (RCTs) on the effect of VitD on human asthma and to retroactively incorporate references to literature were all included in the search criteria. After rigorous screening, quality evaluation, and data extraction of the included literature by two reviewers independently, heterogeneity tests and sensitivity analyses were performed.

The findings show that a total of 12 relevant studies meeting the inclusion criteria were finally included, including 649 cases in the experimental group and 646 cases in the control group. VitD intervention reduced the number of asthma exacerbations, including the rate of exacerbations requiring systemic corticosteroid therapy and the rate of acute exacerbations requiring emergency department or hospital visits or both.

In the outcome of lung function (FEV1% predicted value), it was shown that VitD supplementation improved lung function; in the outcome of serum 25-hydroxyVitD levels, it was shown that VitD supplementation increased serum 25-hydroxyVitD levels.