Table 2.

Vitamin D levels according to clinical variables in the patients with cluster headache

	25(OH)D, ng/mL	p-value
Sex		0.646
Men (n = 24)	13.95 ± 4.08
Women (n = 4)	14.33 ± 2.82
Recurrence		0.300
First episode (n = 6)	14.83 ± 2.42
Recurrent episode (n = 22)	13.78 ± 4.21
Paired comparison		0.421
Cluster period (n = 14)	13.87 ± 3.64
Remission period (n = 14)	14.06 ± 4.56
Diurnal periodicity		0.728
Present (n = 16)	13.69 ± 3.47
Absent (n = 12)	14.41 ± 4.50
Time of propensity		0.125
Nighttime propensity (n = 9)	14.72 ± 3.63
Daytime propensity (n = 7)	11.71 ± 2.63
Recurrence at 3 months		0.562
present (n = 2)	13.00 ± 3.39
absent (n = 26)	14.08 ± 3.97
Seasonal periodicity		0.188
Present (n = 14)	14.63 ± 4.14
Absent (n = 8)	12.29 ± 4.18
Season of cluster period		0.097
Winter to spring (n = 7)	12.30 ± 1.58
Summer to autumn (n = 7)	16.96 ± 4.69
Sampling season		0.001
Winter to spring (n = 15)	11.91 ± 2.63
Summer to autumn (n = 13)	16.41 ± 3.76