Laura Norton1, Sarah Page1, Melissa Sheehan2, Vera Mazurak3, Kim Brunet-Wood2, Bodil Larsen4. 1. Faculty of Agriculture, Life and Environmental Sciences, University of Alberta, Edmonton, Alberta, Canada Alberta Health Services, Edmonton, Alberta, Canada. 2. Alberta Health Services, Edmonton, Alberta, Canada. 3. Faculty of Agriculture, Life and Environmental Sciences, University of Alberta, Edmonton, Alberta, Canada. 4. Alberta Health Services, Edmonton, Alberta, Canada bodil.larsen@albertahealthservices.ca.
Abstract
BACKGROUND: This study aimed to determine the prevalence of inadequate serum 25-hydroxyvitamin D (25(OH)D) levels in a pediatric Canadian cystic fibrosis (CF) population and to assess the effectiveness of a vitamin D supplementation protocol on improving vitamin D status. A secondary objective was to analyze factors that may be associated with inadequate 25(OH)D levels. METHODS: Vitamin D supplementation, 25(OH)D levels, and factors hypothesized to be associated with 25(OH)D levels were collected through a retrospective chart review (2010 and 2011) of 96 patients (1-18 years) at one CF clinic in Canada. Adequacy of 25(OH)D was set at ≥75 nmol/L. Patients with inadequate 25(OH)D levels in 2010 were prescribed an additional 1000 IU/d for levels <60 nmol/L or 400 IU/d for levels 60-75 nmol/L. RESULTS: Inadequate 25(OH)D levels were observed in 26% of patients in 2010 and 23% in 2011. After supplementation was increased for those with inadequate 25(OH)D levels in 2010 (n = 20), a significant increase in 25(OH)D levels was observed in 2011 (P = .03). Adequate status was achieved in 50% of these patients (n = 10). Age was significantly negatively associated with 25(OH)D levels in both years (P = .002). Percentage of forced expiratory volume in 1 second was significantly positively associated with 25(OH)D levels in 2011 (P = .03). CONCLUSION: While vitamin D supplementation was effective at increasing serum 25(OH)D, this protocol did not achieve optimal serum 25(OH)D levels in 25% of the population. Increasing age had the strongest association with 25(OH)D. Current supplementation protocols may require reevaluation based on emerging evidence and revised Cystic Fibrosis Foundation guidelines.
BACKGROUND: This study aimed to determine the prevalence of inadequate serum 25-hydroxyvitamin D (25(OH)D) levels in a pediatric Canadian cystic fibrosis (CF) population and to assess the effectiveness of a vitamin D supplementation protocol on improving vitamin D status. A secondary objective was to analyze factors that may be associated with inadequate 25(OH)D levels. METHODS:Vitamin D supplementation, 25(OH)D levels, and factors hypothesized to be associated with 25(OH)D levels were collected through a retrospective chart review (2010 and 2011) of 96 patients (1-18 years) at one CF clinic in Canada. Adequacy of 25(OH)D was set at ≥75 nmol/L. Patients with inadequate 25(OH)D levels in 2010 were prescribed an additional 1000 IU/d for levels <60 nmol/L or 400 IU/d for levels 60-75 nmol/L. RESULTS: Inadequate 25(OH)D levels were observed in 26% of patients in 2010 and 23% in 2011. After supplementation was increased for those with inadequate 25(OH)D levels in 2010 (n = 20), a significant increase in 25(OH)D levels was observed in 2011 (P = .03). Adequate status was achieved in 50% of these patients (n = 10). Age was significantly negatively associated with 25(OH)D levels in both years (P = .002). Percentage of forced expiratory volume in 1 second was significantly positively associated with 25(OH)D levels in 2011 (P = .03). CONCLUSION: While vitamin D supplementation was effective at increasing serum 25(OH)D, this protocol did not achieve optimal serum 25(OH)D levels in 25% of the population. Increasing age had the strongest association with 25(OH)D. Current supplementation protocols may require reevaluation based on emerging evidence and revised Cystic Fibrosis Foundation guidelines.