Effects of Vitamin D Levels on Long-Term Coronary Events in Patients with Proven Coronary Artery Disease: Six-Year Follow-Up

Abstract

Although some clinical studies have claimed that low-dose vitamin D (Vit-D) increases the risk of long-term cardiac events, in others, no association was found. To better understand the impact of Vit-D levels on long-term cardiac events in coronary artery disease patients, this study was designed. There were 408 patients with coronary artery disease (CAD). The patients were separated into three groups based on their Vit-D levels: group 1 had levels below 10 ng/mL, group 2 had levels between 10 and 20, and group 3 had levels above 20 ng/mL. Six years were spent monitoring the patients for non-fatal MI, death, vascular revascularization, and stable course data. Mortality was found to be similar between groups (group 1: 24.5%; group 2: 13.8%; group 3: 17.4%; p > 0.05). In group 3, 47.8% of the patients did not experience any cardiac event, while 28.7% in group 2 and 27.6% in group 1 did not experience any cardiac event, and these values were found to be significant in favor of group 3 (p = 0.006). Group 3 was found to have considerably lower rates of non-ST-elevated myocardial infarction (non-STEMI) and unstable angina (UA) than the other groups did (group 1: 49%; group 2: 38%; group 3: 27%; p = 0.001). In conclusion, although vitamin D deficiency does not accompany an increase in mortality, it is associated with an increase in non-STEMI and UA in patients who have previously been diagnosed with CAD.