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

Table 1 Clinical characteristics of the cohort according to the Montreal classification n (%)

Characteristics	CD (n = 141)	UC (n = 79)
Females	74 (52)	39 (49)
Age (yr, mean ± SD)	38.5 ± 12.8	47.0 ± 16.1
Disease duration (yr, mean ± SD)	9.8 ± 6.4	10.5 ± 7.2
Location	L1: 63 (45)	E1: 8 (10)
	L2: 29 (21)	E2: 39 (49)
	L3: 44 (31)	E3: 33 (41)
	L4: 4 (3)
Behavior
B1	56 (40)
B2	37 (27)
B3	46 (33)
IBD surgery	46 (33)	2 (3)
VD supplementation	30 (21)	18 (23)

CD: Crohn’s disease; VD: Vitamin D; IBD: Inflammatory bowel diseases; UC: Ulcerative colitis.

Table 2 Vitamin D serum concentrations in the summer/autumn and the winter/spring period and ulcerative colitis/Crohn´s disease cohorts n (%)

VD concentration (nmol/L)	IBD summer/autumn (n = 196)	CD summer/autumn (n = 124)	UC summer/autumn (n = 72)	IBD winter/spring (n = 140)	CD winter/spring (n = 97)	UC winter/spring (n = 43)
< 10	10 (5)	8 (6)	2 (3)	22 (16)	16 (16)	6 (14)
10-19.9	45 (23)	28 (23)	17 (24)	37 (26)	25 (26)	12 (28)
20-29.9	61 (31)	38 (31)	23 (32)	43 (31)	31 (32)	12 (28)
30-30.9	42 (21)	27 (22)	15 (21)	21 (15)	13 (13)	8 (19)
40-40.9	25 (13)	16 (13)	9 (13)	11 (8)	7 (7)	4 (9)
50-50.9	7 (4)	4 (3)	3 (4)	6 (4)	5 (5)	1 (2)
> 60	6 (3)	3 (2)	3 (4)	0	0	0
> 30 (normal)	41%	40%	42%	27%	26%	30%

VD: Vitamin D; IBD: Inflammatory bowel diseases; CD: Crohn´s disease; UC: Ulcerative colitis.

Table 3 Mean short inflammatory bowel diseases questionnaire scores of Crohn's disease and ulcerative colitis patients in the summer/autumn and the winter/spring period according to their vitamin D serum concentrations

VD concentration (ng/mL)	sIBDQ (mean ± SE)
	CD			UC
	Summer/autumn (n= 107)	Winter/spring (n= 87)	All measurements (n= 194)	Summe/autumn (n= 72)	Winter/spring (n= 44)	All measurements (n= 116)
< 10	56.6 ± 3.0	55.8 ± 2.2	56.1 ± 1.7	281	44.5 ± 3.5	42.1 ± 3.8a
10-19.9	58.6 ± 2.3	56.0 ± 2.6	57.3 ± 1.7	54.3 ± 2.4	49.0 ± 3.4	51.7 ± 2.1
20-29.9	58.2 ± 1.7	56.1 ± 1.8	57.0 ± 1.2	56.9 ± 2.9	48.3 ± 4.2	53.0 ± 2.5
30-30.9	58.4 ± 1.7	61.8 ± 2.3	59.6 ± 1.4	56.3 ± 2.5	53.3 ± 5.1	55.1 ± 2.5
40-40.9	56.0 ± 3.0	59.0 ± 6.1	56.8 ± 2.7	58.0 ± 2.2	60.3 ± 3.5	58.9 ± 1.9
50-50.9	66.7 ± 1.7	60.0 ± 3.2	62.9 ± 2.3	63.0 ± 5.0	70	65.3 ± 3.7c
> 60	53.7 ± 6.2	NA	53.7 ± 6.2	451	NA	451

^aP < 0.05 vs all other bins except > 60 ng/mL;

^cP < 0.05 vs the < 10 ng/mL and 10-19.9 ng/mL bins;

¹Too few cases to calculate the mean value. NA: Not available; VD: Vitamin D; IBD: Inflammatory bowel diseases; CD: Crohn‘s disease; UC: Ulcerative colitis; sIBDQ: Short inflammatory bowel diseases questionnaire.

Table 4 Effect of vitamin D supplementation on vitamin D levels and short inflammatory bowel diseases questionnaire in Crohn’s disease and ulcerative colitis patients

Characteristics(mean ± SE)	IBD		CD		UC
	No VD supplementation (n= 90)	VD supplementation (n= 26)	NO VD supplementation (n= 64)	VD supplementation (n= 16)	NO VD supplementation (n= 26)	VD supplementation (n= 10)
VD summer/autumn	30.2 ± 1.4	26.8 ± 2.7	30.3 ± 1.7	27.1 ± 3.4	29.8 ± 2.7	26.4 ± 4.3
sIBDQ summer/autumn	56.7 ± 1.1	54.4. ± 2.1	57.5 ± 1.3	56.5 ± 2.6	54.3 ± 2.3	50.6 ± 3.7
VD next winter/spring	24.0 ± 1.6	25.9 ± 2.5	22.8 ± 1.6	26.4 ± 3.2	27.0 ± 2.5	25.0 ± 4.1
sIBDQ next winter/spring	56.8 ± 1.2	50.2 ± 2.3a	58.6 ± 1.3	54.5 ± 2.5	53.0 ± 2.5	42.9 ± 4.2a
∆ VD (winter/spring-summer/autumn)	-6.2 ± 1.5	-1.0 ± 2.8	-7.5 ± 1.6	-0.7 ± 3.11	-2.8 ± 3.2	-1.4 ± 5.2

¹Not significant;

^aP < 0.05 vs control group. VD: Vitamin D; IBD: Inflammatory bowel diseases; CD: Crohn‘s disease; UC: Ulcerative colitis; sIBDQ: Short inflammatory bowel diseases questionnaire.