Table 3.

Vitamin D levels for surgical site infection, infectious complications, and PoC are shown

Variables	Study population (n = 104) N (%)	25-OH vitamin D levels** Mean values ± SD (median; min–max) ng/ml	U, p-value
Surgical site infection/yes	9 (8.7%)	16.4 ± 9.1 (14.3; 5–60.1)	U = 246.000, p = 0.036*
Surgical site infection/no	95 (91.3%)	11.4 ± 7.7 (8.3; 4.5–25.9)
Infectious complications/yes	18 (17.3%)	16.8 ± 9.4 (14.8; 5–60.1)	U = 515.000, p = 0.026*
Infectious complications/no	86 (82.7%)	12.1 ± 6.2 (11.1; 4.5–25.9)
Postoperative complications/yes	25 (24%)	16.8 ± 9.7 (14.6; 5–60.1)	U = 757.000, p = 0.08
Postoperative complications/no	79 (76%)	13.1 ± 6.2 (11.9; 4.5–25.9)

^* Variables with p value < 0.05

^**In this hypothesis testing table, the power analysis was 75.3%. To obtain a significant difference between categorical variables of vitamin D levels and infectious complications, the number needed to be treated was 6789. To that end, we chose to use scale variables for vitamin D levels to demonstrate the relation with infectious complications. Since it gives the reason of using vitamin D levels as scale variables while analysing its relation to infectious complications (which is the main outcome of the study), not as subgroups of vitamin D levels