A Randomized Controlled Trial of High-Dose Vitamin D3 in Patients With Heart Failure

Objectives The aim of this study was to investigate the effect of vitamin D-3 on physical performance in patients with heart failure (HF). Background HF is associated with functional decline and frailty. Vitamin D deficiency is associated with loss of muscle strength and poor outcomes in patients with HF. Methods Sixty-four patients participated in a 6-month parallel-design, double-blind randomized controlled trial to test the hypothesis that oral vitamin D-3 would improve physical performance. Vitamin D-3 50,000 IU or placebo was given weekly; all patients received daily calcium. Patients were included, regardless of ejection fraction, if they had 25 hydroxyvitamin D (25[OH]D) levels <= 37.5 ng/ml. The primary outcome was peak oxygen uptake, and secondary outcomes were 6-min walk distance, timed get up and go, and knee isokinetic muscle strength. Between-group comparisons were made using analysis-of-covariance models that adjusted for baseline measures. Results Patients' mean age was 65.9 +/- 10.4 years, 48% were women, 64% were African American, the mean ejection fraction was 37.6 +/- 13.9%, 36% were in New York Heart Association functional class III, and the remainder were in functional class II. At baseline, the vitamin D group's mean 25(OH)D level was 19.1 +/- 9.3 ng/ml and increased to 61.7 +/- 20.3 ng/ml; in the placebo group, the mean baseline 25(OH)D level was 17.8 +/- 9.0 ng/ml and decreased to 17.4 +/- 9.8 ng/ml at 6 months (between-groups p < 0.001). There was no significant change from baseline to 6 months in peak oxygen uptake, 6-min walk distance, timed get up and go, or isokinetic muscle strength. Conclusions Vitamin D-3 did not improve physical performance in patients with HF despite a robust increase in serum 25(OH)D levels. Vitamin D repletion in patients with HF should conform to standard adult guidelines for vitamin D supplementation. (A Trial of Vitamin D Therapy in Patients With Heart Failure; NCT01125436) (C) 2013 by the American College of Cardiology Foundation