Vitamin D Supplementation Doesn't Lengthen Walk Distance in Patients with Chronic Heart Failure

Vitamin D deficiency has been linked to developing chronic heart failure (HF), and patients with chronic HF often are vitamin D–deficient. However, studies of vitamin D supplementation in such patients have yielded inconsistent results. In this study, investigators randomized 223 patients (80% men) with chronic HF and vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] level <20 ng/mL) to vitamin D₃ (4000 IU daily) or placebo for 1 year. Enrollment was restricted to those with New York Heart Association class II–III symptoms and left ventricular ejection fractions (LVEFs) ≤45%. The primary outcome was change in 6-minute walk distance at 12 months (compared with the baseline mean of about 290 m).

At 1 year, median 25(OH)D levels were 46…