Pilot Study of Vitamin D Supplementation in Heart Failure

This study is being conducted as a pilot project to determine the feasibility of the methods to inform the conduct of a future larger study. This double-blind randomized controlled trial will examine the relationship between vitamin D status, Quality of Life (QOL), pain and functional capacity of individuals living with heart failure (HF) pre and post vitamin D supplementation. The study outcome measures include: the rate of recruitment, retention and compliance with the study procedures. Quality of life will be measured by the EQ-5D™ questionnaire; the Brief Pain Inventory (BPI) will be used to evaluate subject pain. The 6-minute walk test (6MWT) will evaluate functional capacity. Serum 25-hydroxyvitamin D (25OHD) levels will quantify the adequacy of vitamin D dosing to achieve target 25OHD levels.

A convenience sample of 40 subjects (20 per treatment group) will be prospectively recruited from the Royal Columbian Hospital (RCH) Heart Function (HFx) Clinic. Subjects will be randomized to receive either vitamin D3 (cholecalciferol) or a matching placebo at a dose of 20,000 IU daily for 30 days followed by 20,000 IU once weekly for 8 weeks. Subjects will have their 25OHD levels measured, self-administer the EQ-5D™ and BPI questionnaires and perform the 6MWT at the study entry and again at the completion of the study (12 weeks after entry).

Descriptive statistics (mean, standard deviation and proportion as appropriate) will be used to describe the data. The feasibility of all study procedures will be reported by percentage and compared to the standard set by the team of 80%.