Table 2.

The relation between vitamin D levels and variables of the study

	Correlation with Vitamin D	Extreme deficiency	Deficiency	Normal	Dangerous	P-value
Age	R= -0.062 P=0.385	32.62±4.63	31.74±5.55	31±6.47	30.67±3.78	0.5
Work experience	R= -0.028 P=0.691	9.51±4.1	8.99±5.39	8.53±5.84	9.67±5.5	0.8
Number of shifts in month	R= 0.141 P=0.046	30.44±2.35	29.99±3.32	33.16±5.96	30.67±2.08	0.003
Fatigue scores	R= -0.364 P=0.0001	41. 9±12.3	39.06±11	25±11.62	22±1.73	0.001
Visual fatigue scores	R= -0.418 P=0.0001	6.38±2.27	5.68±1.49	3.37±1.77	2.33±0.57	0.001