Vitamin D Status and the Index of Cardiac Electrophysiological Balance: A Cross-Sectional Study

Objective: To examine whether vitamin D deficiency is associated with the index of cardiac electrophysiological balance (iCEB), its corrected form (iCEBc), and other resting electrocardiographic parameters in adults.
Method: Between January and April 2024, 196 adults were included in this cross-sectional study: 140 with serum 25-hydroxyvitamin D [25(OH)D] concentrations below 20 ng/mL (49.9 nmol/L) and 56 in the nondeficient comparison group. Blood sampling and 12-lead electrocardiography were performed on the same day. The index of cardiac electrophysiological balance (iCEB) was calculated as QT/QRS, and the corrected index of cardiac electrophysiological balance (iCEBc) was calculated as the heart rate-corrected QT interval (QTc)/QRS. Statistical analyses included between-group comparisons, correlation analysis, and multivariable linear regression.
Results: Median iCEB values were 4.24 [3.91–4.63] in the vitamin D-deficient group and 4.29 [4.09–4.56] in the comparison group (P=.39). Median iCEBc values were 4.72 [4.32–5.08] and 4.74 [4.39–5.02], respectively (P=.90). QTc and the frontal QRS-T angle were also similar between the groups. In adjusted analyses, vitamin D status was not independently associated with iCEB, iCEBc, QTc, or the frontal QRS-T angle. Continuous 25(OH)D concentrations were not significantly associated with these outcomes.
Conclusion: No association was detected between vitamin D deficiency and the selected resting electrocardiographic indices in this sample. These findings do not exclude clinically relevant electrophysiological effects or differences in arrhythmic risk.

Keywords: Arrhythmias, cardiac, cardiac electrophysiology, electrocardiography, Vitamin D deficiency