Higher vitamin D serum concentration increases health related quality of life in patients with inflammatory bowel diseases

Figure 1 Differences in the mean vitamin D serum concentrations of inflammatory bowel disease patients between summer and winter. The horizontal lines represent the mean ± SE. VD: Vitamin D.

Figure 2 Mean short inflammatory bowel diseases questionnaire score in the winter/spring period according to vitamin D status. A: UC patients; B: CD patients. Low VD serum concentration (< 30 ng/mL), Normal VD serum concentration (> 30 ng/mL). CD: Crohn´s disease; UC: Ulcerative colitis; VD: Vitamin D; sIBDQ: Short inflammatory bowel diseases questionnaire.

Figure 3 Effect of vitamin D serum concentration on disease activity according to diagnosis and season. The horizontal lines represent the sIBDQ score mean ± SE. VD serum concentration bins: 0: 0-9.9 ng/mL; 1: 10-19.9 ng/mL; 2: 20-29.9 ng/mL; 3: 30-39.9 ng/mL; 4: 40-49.9 ng/mL; 5: 50-50.9 ng/mL; 6: > 60 ng/mL. VD: Vitamin D; sIBDQ: Short inflammatory bowel diseases questionnaire.

Figure 4 Correlation between vitamin D serum concentration and short inflammatory bowel diseases questionnaire score. A: CD patients in winter; B: UC patients in winter. sIBDQ: Short inflammatory bowel diseases questionnaire; VD: Vitamin D; CB: Confidence border; CD: Crohn´s disease.

Figure 5 Correlation between the change in vitamin D serum concentration from summer to winter and the winter short inflammatory bowel diseases questionnaire score in ulcerative colitis patients. VD average is the mean value of the summer/autumn and winter/spring VD serum concentrations. sIBDQ 1H2013 is the sIBDQ score measured in the winter/spring period of 2013. sIBDQ: Short inflammatory bowel diseases questionnaire; UC: Ulcerative colitis; VD: Vitamin D; CB: Confidence border.