(61) High Dose (Stoss) Vitamin D Supplementation in Cystic Fibrosis: A Quality Improvement Project

Background: Deficiency of Vitamin D, a fat-soluble vitamin, is common in persons with CF (PwCF); the cause is multifactorial and related to exocrine pancreatic insufficiency (EPI) and intestinal inflammation causing fat maldigestion and malabsorption. Vitamin D deficiency can lead to poor bone health (osteomalacia) and has been associated with worsening lung disease in PwCF[1]. Despite this knowledge and prescription of daily vitamin D supplementation for PwCF, vitamin D deficiency has remained common in our adult and pediatric CF clinics. Use of high-dose vitamin D therapy (Stoss) has been shown to improve vitamin D levels [2, 3], and our adult and pediatric CF clinics participated in a regional (Northern New England Cystic Fibrosis Consortium) quality improvement initiative to implement Stoss vitamin D dosing into routine clinical care. The aims of this initiative were to 1.) Utilize Stoss dosing during clinic (in-person and telemedicine) visits and 2.) Achieve sufficient vitamin D levels (≥ 30 ng/mL) in 25% of our patients with vitamin D deficiency.

Methods: Quality improvement tools, including a swim lane diagram and plan-do-study-act (PDSA) cycles, were used to implement Stoss dosing into our usual clinic workflow. Patients ≥ 5 years of age with vitamin D deficiency (vitamin D < 30 ng/mL) followed in the pediatric and adult CF clinics at the University of Vermont Medical Center were included in this QI initiative. Baseline vitamin D levels were obtained as part of routine annual laboratory evaluation. The CF dietitian directly observed Stoss dosing during in-person and telemedicine clinic visits (in person and telemedicine). A high fat snack (with enzyme supplementation in patients with EPI) was ingested with vitamin D. Vitamin D levels were re-assessed according to Figure 1. PDSA cycles were reviewed at monthly multi-disciplinary QI meetings. This project was a Quality Improvement Initiative at the University of Vermont/University of Vermont Medical Center, and as such was not formally supervised by the Institutional Review Board per their policies.

Results: High dose (Stoss) vitamin D dosing was successfully implemented into our routine clinical care. 56 patients ≥ 5 years of age had a vitamin D level < 30 ng/mL; 35 (62%) had a vitamin D level ≥20-30 ng/mL, and 21 (38%) had a vitamin D level < 20 ng/mL (range 5-29.8 ng/mL). Forty-five patients received Stoss dosing, and 37 patients had a repeat vitamin D level (mean time post-Stoss dose 115 days, range 45-238 days). Following a single Stoss dose, 17/37 (46%) had a level ≥30, and 7 (19%) had a vitamin D level < 20 ng/mL (range 6-51 ng/mL). No adverse events (including vitamin D toxicity) were observed.

Conclusions: High dose (Stoss) vitamin D dosing can be successfully implemented into routine CF care and improves vitamin D status in PwCF and vitamin D deficiency.

Acknowledgements:

References: 1. McCauley LA, Thomas W, Laguna TA, Regelmann WE, Moran A, Polgreen LE. Vitamin D deficiency is associated with pulmonary exacerbations in children with cystic fibrosis. Ann Am Thorac Soc. 2014;11(2):198-204.

2. Shepherd D, Belessis Y, Katz T, Morton J, Field P, Jaffe A. Single high-dose oral vitamin D3 (stoss) therapy--a solution to vitamin D deficiency in children with cystic fibrosis? Journal of cystic fibrosis: official journal of the European Cystic Fibrosis Society. 2013;12(2):177-82.
3. Janzen KM, Sakon C, Lehman A, Sommer B, Brown C. High-dose Cholecalciferol Supplementation in Adults with Cystic Fibrosis. Pharmacotherapy. 2019;39(9):874-80.