Materials and Methods: This cross-sectional study was performed on 80 consecutive patients who were the candidate for diagnostic coronary angiography and demonstrated a sign of slow coronary flow (SCF) or minimal coronary artery disease (CAD) while without any evidence of CAD. The serum level of 25-hydroxy vitamin D was measured by ELISA (enzyme-linked immunosorbent assay) method. Finally, patients were evaluated by transthoracic 2D, Doppler echocardiography, and tissue Doppler imaging in order to investigate the systolic and diastolic function of the left ventricle.

Results: Based on angiography reports, 36.2% of patients had normal coronaries while 50.0%, 7.6%, and 6.2% of them were diagnosed with isolated minimal CAD, isolated SCF, and a combination of minimal CAD and SCF, respectively. In addition, the mean serum level of 25-hydroxy vitamin D in our patients was 30.33 ± 19.27. Further, the mean level of this parameter was 29.37 ± 22.16, 30.39 ± 16.22, 18.24 ± 4.32, and 44.65 ± 25.52 in the normal coronary group, as well as patients with isolated minimal CAD, concurrent minimal CAD and SCF, and those with isolated SCF, respectively, indicating no significant difference among the groups regarding 25-hydroxy vitamin D concentration (P = 0.147). Furthermore, the level of 25-hydroxy vitamin D had no relationship with the echocardiography indices of the LV function or valvular defects.

Conclusions: In general, the serum level of 25-hydroxy vitamin D may not be a predictive factor for the LV function or valvular defects.