Impact of vitamin D supplementation on markers of inflammation in adults with cystic fibrosis hospitalized for a pulmonary exacerbation

Abstract

Patients with cystic fibrosis (CF) suffer from chronic lung infection and inflammation leading to respiratory failure. Vitamin D deficiency is common in patients with CF, and correction of vitamin D deficiency may improve innate immunity and reduce inflammation in patients with CF. We conducted a double-blinded, placebo-controlled, randomized clinical trial of high-dose vitamin D to assess the impact of vitamin D therapy on antimicrobial peptide concentrations and markers of inflammation. We randomized 30 adults with CF hospitalized with a pulmonary exacerbation to 250,000 IU of cholecalciferol or placebo, and evaluated changes in plasma concentrations of inflammatory markers and the antimicrobial peptide LL-37 at baseline and 12 weeks post intervention. In the vitamin D group, there was a 50.4% reduction in tumor necrosis factor-α (TNF-α) at 12 weeks (P<0.01), and there was a trend for a 64.5% reduction in interleukin-6 (IL-6) (P=0.09). There were no significant changes in IL-1β, IL-8, IL-10, IL-18BP and NGAL (neutrophil gelatinase-associated lipocalin). We conclude that a large bolus dose of vitamin D is associated with reductions in two inflammatory cytokines, IL-6 and TNF-α. This study supports the concept that vitamin D may help regulate inflammation in CF, and that further research is needed to elucidate the potential mechanisms involved and the impact on clinical outcomes.

Conflict of interest statement

CONFLICT OF INTEREST

Dr Tangpricha received an unrestricted research grant from BTR, Group (a vitamin D supplement company). The remaining authors declare no conflict of interest.

Figures

Figure 1

Mean change in plasma concentrations of TNF-α (tumor necrosis factor-α) and IL-6 (interleukin-6) at baseline, 1 week and 12 weeks in CF (cystic fibrosis) adults randomized to 250 000 IU cholecalciferol or placebo. (a) Mean change in TNF-α plasma concentrations. In the vitamin D group, TNF-α decreased 3.56 and 27.83 pg/ml at 1 week and 12 weeks (P = 0.6, 0.0002); TNF-α remained unchanged in the placebo. (SEM bars). (b) Mean change in plasma concentrations of IL-6. In the vitamin D group, IL-6 decreased 12.39 and 5.16 pg/ml at 1 week and 12 weeks (P = 0.004, 0.35); IL-6 remained unchanged in the placebo (SEM bars).