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

ObjectivesThe aim of this study was to investigate the effect of vitamin D3 on physical performance in patients with heart failure (HF).BackgroundHF is associated with functional decline and frailty. Vitamin D deficiency is associated with loss of muscle strength and poor outcomes in patients with HF.MethodsSixty-four patients participated in a 6-month parallel-design, double-blind randomized controlled trial to test the hypothesis that oral vitamin D3 would improve physical performance. Vitamin D3 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.ResultsPatients’ 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.ConclusionsVitamin D3 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)