Vitamin D Supplementation Protocol in Osteoporosis: Chart Review

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 238-262-Vitamin D Action, Deficiency & Disorders
Bench to Bedside
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-256
Vithika Sivabalasundaram*1, Sandra Ann Kim2, Ina Radziunas3 and Sophie Jamal*4
1University of Toronto, Toronto, ON, Canada, 2Univ of Toronto, Toronto, ON, Canada, 3Women's College Hospital, 4University of Toronto, Toronto, Canada
Introduction: There is strong evidence that vitamin D supplementation prevents against fractures, and many treatment options for osteoporosis require adequate vitamin D stores for improved efficacy. Current guidelines recommend supplementation to a target of 75 nmol/L. The ideal dosing strategy to achieve this target however remains undetermined. In addition, given the high cost of vitamin D serum testing, a cost effective method of replacing and monitoring vitamin D is required. The purpose of this study is to evaluate the efficacy of a newly developed dosing protocol to guide vitamin D supplementation and testing.

Methods: This chart review gathered clinical information from 376 subjects seen in the Osteoporosis Program at Women’s College Hospital who were found to be vitamin D deficient (<50 nmol/L) or insufficient (50-74 nmol/L) and underwent treatment with the Vitamin D Protocol. This protocol outlined a specific algorithm for physicians to replace vitamin D. Patients were instructed to repeat blood work in 6 months. Patient with the following medical comorbidities were excluded: renal failure, hypercalcemia, hypercalciuria, renal calculi and teriparatide therapy.  

Results: 376 charts were reviewed and of the 325 eligible subjects, 169 (52%) completed post-protocol blood work. The mean increase in vitamin D after treatment was 23.0 +/- 31.1 nmol/L. 56% of subjects achieved the target Vitamin D level of 75 nmol/L or greater following the protocol. Patients with a post-protocol vitamin D level <75 nmol/L were more likely to have a malabsoprtion syndrome (18.9% vs 7.4%, p=0.02) and took longer to complete their post protocol bloodwork (9.3 vs 7.9 months, p=0.002). Other demographic and clinical factors such as gender, age, BMI, baseline BMD and history of fragility fracture were similar in both groups. 28 patients in the group which did not achieve target had in fact a lower vitamin D level after the protocol than baseline.

Conclusion:This is the first protocol for vitamin D supplementation to be studied and demonstrates a significant improvement in vitamin D levels by nearly 50%. Compliance in our study was low with 52% of patients completing blood work. While only 56% of patients achieved the target vitamin D level, there is likely a large component of laboratory variability in testing results, given that 17% of patients had a lower vitamin D level following treatment with the protocol.

Disclosure: SJ: Speaker, Bristol-Myers Squibb, Speaker, Shire, Consultant, Genzyme Corporation, Advisory Group Member, Warner Chilcott, Advisory Group Member, Novartis Pharmaceuticals, Advisory Group Member, Amgen, Speaker, Sanofi, Consultant, Cytochroma. Nothing to Disclose: VS, SAK, IR

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm