Vitamin D and its binding protein in children with cystic fibrosis: A single center study

AimTo measure the level of VDBP (vitamin D binding protein) and serum 25-hydroxy vitamin D (25OHD) in order to assess its role as a nutritional marker in cystic fibrosis (CF). The relationship between vitamin DBP and immunoglobulin G (IgG) levels was assessed as well.MethodsThis is a cross-sectional observational study recruiting 50 patients diagnosed as having CF from the Allergy and Pulmonology Unit, Children’s Hospital, Cairo University, from May 2012 until May 2013, twenty age- and sex-matched healthy children were included as a control group. Vitamin DBP and 25OHD were measured using Elisa technique and total IgG was measured using the nephelometer method.ResultsThe CF group had significantly lower serum concentrations of DBP (p < 0.012) and 25OHD (p < 0.001) while IgG levels were within normal values (p < 0.216) compared to the control group, patients with failure to thrive (FTT) have significantly lower levels of 25OHD and significantly higher levels of VDBP and nearly the same level of IgG. Patients with pancreatic insufficiency have significantly higher serum levels of VDBP.ConclusionsThe present study has demonstrated that the levels of 25OHD and VDBP are decreased in CF patients while IgG levels are within normal values. In addition, the serum level of 25OHD was significantly lower in patients with FTT, also significant relations of VDBP with failure to thrive and pancreatic insufficiency were noted, emphasizing its role as a marker for the nutritional status in CF patients. As a component of anti-inflammatory and nutritional therapy, vitamin D is a predictor for clinical outcomes.