Pleiotropic effect of vitamin D in cystic fibrosis.

Cystic fibrosis - CF - is the most common recessively autosomally and inherited disorder in the Caucasian population. It is incurable, multi-systemic disease with progressive course. CF is caused by CFTR gene mutation, the product of which is Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). CF patients are exposed to fat-soluble vitamins deficiency, including vitamin D. It is due to the fat malabsorption (caused by exacerbation exocrine pancreatic insufficiency), decreased sun exposure (caused by receiving antibiotics photophobia), reduction of adipose tissue and insufficient supply with food. The discovery of vitamin D receptor (VDR) presence outside the skeletal system allowed to conclude, that vitamin D is responsible not only for mineral economy, but also for immunological processes, respiratory status, intestial microflora and cystic fibrosis - related diabetes (CFRD) course. Based on literature data, it is suggested that vitamin D plays an important role in the prevention of diseases coexisting with CF. The right dosage of vitamin D allows to maintain a better lung function and prevent chronic pulmonary infections. It has also been shown that normal levels of vitamin D may be important in increasing the chances of successful lung transplant surgery. Taking the wide spectrum of vitamin D effect into account, it is recommended to maintain serum concentrations above the minimum in patients with CF. In summary, maintaining the proper vitamin D levels in patients with CF is important because of its pleiotropic effect. It can be achieved through regular monitoring of vitamin D levels and individual supplementary dose for each patients.