Background/Introduction:Recent studies have indicated a much broader role to Vitamin D than simply the regulation of calcium metabolism alone. Vitamin D likely confers physiologically relevant pleiotropic functions that include cardioprotective and immunomodulatory effect, and its deficiency could lead to increased risk of cardiovascular disease and heart failure.Aim:The aim of our work was to evaluate the presence of hypovitaminosis D in patients with dilated cardiomyopathy (DCMP) and to study any correlation of echocardiographic parameters with Vitamin D deficiency.Patients and Methods:In an observational case–control hospital-based study, 56 patients diagnosed to have DCMP and 60 age-, gender-, and body mass index-matched controls who were patients of other medical illnesses were included in the study. Each subject underwent transthoracic two-dimensional guided M-mode echocardiography, and Vitamin D, parathyroid hormone (PTH), and N-terminal pro-B-type natriuretic peptide (NT-ProBNP) were assessed.Results:Mean 25-hydroxyvitamin D3 [25(OH) D3] levels were significantly lower (14.5 ± 7.4 ng/ml vs. 28.2 ± 12 ng/ml, P = 0.001), whereas PTH (90.5 ± 28.5 pg/ml vs. 57 ± 20.2 pg/ml, P = 0.02) and NT-proBNP levels were significantly greater in patients with DCMP than controls. In DCMP group, 24/56 patients had severe Vitamin D deficiency, whereas in control group, 10/60 patients had severe hypovitaminosis D. There was a significant negative correlation between 25(OH) D3 concentrations and left ventricular (LV) end-diastolic and LV end-systolic dimensions.Conclusion:Patients with DCMP had lower Vitamin D levels than controls, and Vitamin D deficiency had a significant correlation with cardiac function. Therefore, screening for Vitamin D deficiency along with prompt treatment is recommended in patients with DCMP.