Background: Low 25-hydroxyvitamin D levels, commonly found in older patients with heart failure, may contribute to the chronic inflammation and skeletal myopathy that lead to poor exercise tolerance. We tested whether vitamin D supplementation of patients with heart failure and vitamin D insufficiency can improve physical function and quality of life.
Methods and results: In a randomized, parallel group, double-blind, placebo-controlled trial, patients with systolic heart failure aged >or=70 years with 25-hydroxyvitamin D levels <50 nmol/L (20 ng/mL) received 100,000 U of oral vitamin D2 or placebo at baseline and 10 weeks. Outcomes measured at baseline, 10 weeks, and 20 weeks were 6-minute walk distance, quality of life (Minnesota score), daily activity measured by accelerometry, Functional Limitations Profile, B-type natriuretic peptide, and tumor necrosis factor-alpha. Participants in the vitamin D group had an increase in their 25-hydroxyvitamin D levels compared with placebo at 10 weeks (22.9 versus 2.3 nmol/L [9.2 versus 0.9 ng/mL]; P<0.001) and maintained this increase at 20 weeks. The 6-minute walk did not improve in the treatment group relative to placebo. No significant benefit was seen on timed up and go testing, subjective measures of function, daily activity, or tumor necrosis factor. Quality of life worsened by a small, but significant amount in the treatment group relative to placebo. B-type natriuretic peptide decreased in the treatment group relative to placebo (-22 versus +78 pg/mL at 10 weeks; P=0.04).
Conclusions: Vitamin D supplementation did not improve functional capacity or quality of life in older patients with heart failure with vitamin D insufficiency. Clinical Trial Registration- www.controlled-trials.com. Identifier: ISRCTN51372896.