Background: Acute coronary syndrome (ACS) is an acute subset of coronary heart disease that requires immediate treatment. ACS is at a high prevalence in Indonesia. Homocysteine is another product of methionine metabolism. Hyperhomocysteinemia is known to cause ACS through several mechanisms, namely inducing oxidative stress, endothelial injury, and increased likelihood of plaque rupture. Vitamin D is a hormone needed by the body that comes from food or is produced through the metabolism of Vitamin D. Vitamin D functions as an anti-inflammatory, anti-thrombotic and anti-atherosclerotic agent. This study aimed to analyze the relationship between homocysteine level and Vitamin D deficiency with acute coronary syndrome incidence. Methods: This study was a cross-sectional, observational analysis study with 90 subjects. Subjects were enrolled into two groups; patients with ACS and patients with health control based on age. All subjects were selected from Universitas Airlangga Hospital, Surabaya. Serum homocysteine level and Vitamin D deficiency were calculated using an enzyme-linked immunosorbent assay (ELISA). The relationship between serum homocysteine level and Results: Ninety subjects were obtained in this study. The mean age was 62.1±10.9 years (among patients with ACS) and 60.1±10.3 years (healthy persons), with 55.6% male patients. The traditional risk factors i.e., diabetes, hypertension, and dyslipidemia were 62.2%, 91.1%, and 75.6%, respectively. The Chi-square analysis results showed homocysteine level and ACS obtained a contingency coefficient of 0.270 (p = 0.008) and Vitamin D with ACS had a contingency coefficient of 0.468 (p = < 0.001). Conclusions: There was a weak association between homocysteine level and ACS and a moderate association between Vitamin D deficiency and ACS.
