Vitamin D deficiency in patients with cystic fibrosis: a systematic review and meta-analysis

Aim Vitamin D is a prominent modulator of immunity and respiratory function. It plays a vital role in respiratory diseases such as cystic fibrosis (CF). S. However, there is a dearth of information on patients with CF. The purpose of the meta-analysis is to highlight the importance of following the existing guidelines regarding maintenance of Vitamin D serum levels in patients with CF. Methods The systematic search was conducted without utilizing any time or language limitations in original database from the beginning until March 2022. The meta-analysis was performed using a random-effects model. Heterogeneity was determined by I 2 statistics and Cochrane Q test. Results Pooled analysis using the random-effects model of the 8 case–control studies with 13 effect sizes revealed that the serum 25-OH-vitamin D in participants with cystic fibrosis was significantly lower than controls in pediatrics and adolescences (WMD: − 3.41 ng/ml, 95% CI − 5.02, − 1.80, p = < 0.001) and adults (WMD: − 2.60 ng/ml, 95% CI − 4.32, − 0.89, p = 0.003). Based on data from 12 studies (21 effect sizes) with a total of 1622 participants, the prevalence of vitamin D levels of 20–30 ng/ml in CF patients was 36% among pediatrics/adolescents and 63% among adults. In addition, 27% of pediatric/adolescent CF patients and 35% of adult CF patients had vitamin D levels of below 20 ng/ml. Conclusions As a result, according to the existing guidelines, our results proved the need to pay attention to the level of vitamin D in these patients.