Table 1.

Comparison of demographic and baseline data between the study groups

	Vit D (n=54)	Placebo (n=53)	P-valuea)
Age (yr)	22.7±3.9	22.5±3.3	0.895
BMI (kg/m2)	24.0±2.6	23.3±3.1	0.273
Age at menarche (yr)	14.0±1.2	14.0±1.5	0.490
Menstrual cycle interval (day)	23.2±2.9	23.9±3.3	0.286
Duration of bleeding (day)	6 (5, 7)	5 (5, 7)	0.245
Serum 25[OH]D level (ng/mL)	20.0±6.0	19.5±5.5	0.715
Pain intensity	7.0±1.7	6.6±1.5	0.392
Days with pain	2 (1, 3)	2 (2, 3)	0.193
Pain medication (day)	2 (1, 3)	1 (0, 2)	0.042b)
Nausea/vomiting	2 (1, 3)	2 (1, 3)	>0.999
Diarrhea	0 (0, 1)	0 (0, 1)	>0.999
Headache	1 (0.2, 2)	1 (1, 2)	0.636
Fatigue	2 (1, 3)	2 (1, 3)	0.447
Systemic symptoms total score	5.5±2.3	5.2±2.6	0.485

Values are presented as mean±standard deviation or median (interquartile range 25%, 75%).

BMI, body mass index.

^a)Mann-Whitney U Test;

^b)Indicating a significant difference.