Introduction:
The growing interest in vitamin D deficiency as a potential contributor to coronary artery disease (CAD) has prompted increased scrutiny. Nevertheless, its status as a confirmed risk factor remains unestablished. This study seeks to explore the connection between serum vitamin D levels and CAD.

Material and methods:
Employing a cross-sectional approach, 205 patients eligible for coronary computed tomography angiography (CCTA) were chosen. Serum vitamin D levels were assessed and juxtaposed with the outcomes of CCTA, which encompassed the coronary artery calcium score (CACS), as well as the presence and severity of coronary artery involvement attributed to atherosclerotic plaques.

Results:
The average age of the participants was 61.4 ±10.8 years, and the mean serum vitamin D level was 19.6 ±10.3 ng/dl (ranging from 4.7 to 39.7 ng/dl). In total, 52.1% of the participants (n = 107) exhibited vitamin D deficiency, while 47.9% (n = 98) had no deficient levels of vitamin D. The mean serum vitamin D level was notably lower in patients with severe coronary artery disease (CAD) (p < 0.0001). According to the Spearman test, a significant negative correlation (–0.48) was identified between the serum vitamin D level and CACS (p < 0.0001). Conversely, the mean CACS in the vitamin D deficient group was significantly higher than in the insufficient and non-insufficient vitamin D groups (p < 0.0001 for both comparisons).

Conclusions:
There was a correlation between vitamin D deficiency and both CACS and the severity of coronary artery stenosis.