Effects of Vitamin D on Left Ventricular Ejection Fraction in Patients with Systolic Heart Failure: A Double-Blind Randomized Clinical Trial

Background: Heart failure is a pathophysiologic state in which the cardiac output is not able to supply the body with enough oxygen and nutrients. The prevalence of heart failure has increased dramatically over the last decades. Vitamin D levels in patients with chronic heart failure are lower than healthy controls, and vitamin D deficiency has a direct relationship with mortality. Objectives: This study aimed to evaluate the effect of vitamin D on the improvement of left ventricular ejection fraction in patients with systolic heart failure. Methods: In this case-control clinical trial, 142 patients with chronic systolic heart failure were identified. Based on the inclusion and exclusion criteria, 114 patients were enrolled in the study and randomly divided into two groups. One group (n = 58) received 50,000 units of vitamin D capsules weekly for eight weeks, and the patients in the other group (n = 56) received a placebo. After excluding 15 patients from the placebo group and 17 patients from the intervention group during the study, according to the exclusion criteria, 41 patients were evaluated in both groups for ejection fraction changes after two months. Results: According to the results of this research, there were no statistically significant differences in the baseline parameters between the two studied groups. The intervention group consisted of 18 female and 23 male patients with a mean age of 61.68 ± 19.8 years. Moreover, the placebo group included 21 female and 20 male patients with a mean age of 62.12 ± 18.2 years. After a 2-month follow-up, the intervention group showed statistically significant changes in ejection fraction, end-diastolic volume, and heart failure class compared to the placebo group. Also, the serum level of albumin and vitamin D in the intervention group was significantly higher than the placebo group. Conclusions: The results of this study show that vitamin D treatment can improve the ejection fraction and functional ability of patients with vitamin D deficiency. If more comprehensive studies support this hypothesis, vitamin D deficiency assessment and correction in patients with chronic heart failure may be recommended.