Table 2.

Comparison of the pain-related outcomes between and within the vitamin D (n=54) and placebo (n=53) groups from baseline to week 8 after the intervention

	Baseline	Week 4	Week 8	P-value 1a)	P-value 2b)
Pain intensity
Vit D	7.0±1.7	6.3±1.7	5.6±1.7	<0.001c)	<0.001c)
Placebo	6.6±1.5	6.6±1.5	6.5±1.6	>0.999	0.809
P-value 3d)	0.392	0.618	0.033
Days with pain
Vit D	2 (1, 3)	2 (1, 3)	1 (1, 2)	<0.001c)	<0.001c)
Placebo	2 (2, 3)	2 (2, 3)	2 (2, 3)	>0.999	>0.999
P-value 3d)	0.193	0.030	<0.001
Pain medication (day)
Vit D	2 (1, 3)	1.5 (0, 2)	1 (0, 2)	<0.001c)	<0.001c)
Placebo	1 (0, 2)	1 (0, 2)	1 (0, 2)	>0.999	0.803
P-value 3d)	0.042	0.546	0.441

Values are presented as mean±standard deviation or median (interquartile range 25%, 75%). 0=no symptom, 1=mild, 2=moderate, and 3=severe symptom.

^a)Wilcoxon signed-rank test, week 4 vs. baseline, corrected based on the Holm-Bonferroni method;

^b)Wilcoxon signed-rank test, week 8 vs. baseline, corrected based on the Holm-Bonferroni method;

^c)Indicating a significant difference;

^d)Mann-Whitney U test, corrected based on the Holm-Bonferroni method.