Table 3.

The mean difference of the effect of Vitamin D versus placebo on symptoms severity score, irritable bowel syndrome-quality of life, and total score between the groups

Characteristic	Vitamin D group		Placebo group		Crude (P)	Adjusted (P)
	Crude	Adjusted	Crude	Adjusted
SSS (mean±SE)a	60.23±12.67	61.46±14.54	34.45±13.76	35.55±13.54	<0.05	<0.05
IBS-QOL (mean±SE)a	44.17±6.98	48.13±4.24	39.13±4.87	35.18±4.24	0.556	0.039*
Total score (mean±SE)a	66.52±5.35	66.69±4.08	26.30±3.30	26.14±4.08	<0.001*	<0.001*

Crude significances are based on independent t-test and adjusted significances are based on ANCOVA adjusting the effects of age, IBS-QOL baseline score, and baseline value of each factor as covariates, *Statistically significant, ^aOn week 6, ^bOn week 10. SSS=Symptoms severity score, QOL=Quality of life, SE=Standard error, IBS=Irritable bowel syndrome, ANCOVA=Analysis of covariance