Predictors of vitamin D deficiency in inflammatory bowel disease and health: A Mississippi perspective

Table 1 Comparison between inflammatory bowel disease patients with and without available vitamin D concentration n (%)

	IBD patients without available vitamin D concentration(n = 26)	IBD patients with available vitamin D concentration(n = 211)	P value
CD	10 (38.5)	129 (61.1)	0.034
Age (yr), median (IQR)	32 (26)	41 (25)	0.030
Female	12 (46.2)	125 (59.2)	0.213
AA	11 (42.3)	91 (43.1)	0.391
BMI (kg/m2), median (IQR)	25.6 (9.9)	27 (8.9)	0.176
Patients on vitamin D supplementation	2 (8.33)	36 (17.06)	0.271

CD: Crohn’s disease; AA: African American; BMI: Body mass index.

Table 2 Comparison between inflammatory bowel disease and non- inflammatory bowel disease patients n (%)

	Controls	IBD patients	P value
	(n = 98)	(n = 211)
Patients with vitamin D deficiency	56 (57.1)	143 (61.6)	0.0694
Age at vitamin D testing (yr), median (IQR)	60.5 (14.5)	41 (25)	< 0.0001
Female	86 (87.8)	125 (59.2)	< 0.0001
AA	23 (23.9)	91 (43.1)	0.0009
BMI (kg/m2), median (IQR)	29.3 (7.5)	27 (8.9)	0.0438
Patients receiving vitamin D supplementation	Not available	36 (17.06)	Not Applicable

AA: African American; BMI: Body mass index.

Table 3 Distribution of vitamin D concentration across various diagnosis, demographics (age, race, gender) and body mass index (modifiable risk factor) n (%)

		Vitamin D			P value
		Deficient	Insufficient	Sufficient
Total	309	100	99	110
		(32.4)	(32.0)	(35.6)
Diagnosis
Controls	98 (31.7)	27.6%	29.6%	42.8%	0.0407
CD	129 (41.7)	40.3%	33.3%	26.4%
UC	82 (26.5)	25.6%	32.9%	41.5%
Age (yr)
< 35	72 (23.3)	38.9%	34.7%	26.4%	0.0415
35-49	73 (23.6)	34.2%	28.8%	37.0%
50-64	99 (32.0)	37.4%	28.3%	34.3%
> 65	65 (21.0)	15.4%	38.5%	46.2%
Race
White	189 (61.2)	21.7%	34.4%	43.9%	< 0.0001
AA	114 (36.9)	50.9%	28.1%	21.0%
Other	6 (1.9)	16.7%	33.3%	50.0%
Gender
Female	211 (68.3)	33.7%	32.2%	34.1%	0.6857
Male	98 (31.7)	29.6%	31.6%	38.8%
BMI (kg/m2)
< 25	97 (31.4)	29.9%	25.8%	44.3%	0.0110
25-30	102 (33.0)	27.5%	31.4%	41.2%
> 30	110 (35.6)	39.1%	38.2%	22.7%

CD: Crohn’s disease; AA: African American; BMI: Body mass index; UC: Ulcerative colitis.

Table 4 Associations of body mass index with diagnosis and demographic variables

	n (%)	BMI < 25 kg/m2	BMI 25-30 kg/m2	BMI > 30 kg/m2	P value
Total	309	97	102	110
		(31.4)	(33.0)	(35.6)
Diagnosis
Controls	98 (31.7)	20.4%	34.7%	44.9%	0.0048
CD	129 (41.7)	42.6%	29.5%	27.9%
UC	82 (26.5)	26.8%	36.6%	36.6%
Age (yr)
< 35	72 (23.3)	52.8%	29.2%	18.1%	0.0007
35-49	73 (23.6)	26.0%	30.1%	43.8%
50-64	99 (32.0)	23.2%	37.4%	39.4%
> 65	65 (21.0)	26.2%	33.9%	40.0%
Race
White	189 (61.2)	28.6%	36.5%	34.9%	0.5253
AA	114 (36.9)	36.0%	27.2%	36.8%
Other	6 (1.9)	33.3%	33.3%	33.3%
Gender
Female	211 (68.3)	27.5%	30.3%	42.2%	0.0017
Male	98 (31.7)	39.8%	38.8%	21.4%

CD: Crohn’s disease; AA: African American; BMI: Body mass index; UC: Ulcerative colitis.

Table 5 Distribution of vitamin D concentration across stratified levels of body mass index and diagnosis

	n (%)	Vitamin D deficient	Vitamin D insufficient	Vitamin D sufficient	P value
BMI < 25 (kg/m2)
Total	97	29	25	43
		(29.9)	(25.8)	(44.3)
Diagnosis
Controls	20 (20.6)	15.0%	15.0%	70.0%	0.0026
CD	55 (56.7)	43.6%	27.3%	29.1%
UC	22 (22.7)	9.1%	31.8%	59.1%
BMI = 25-30 (kg/m2)
Total	102	28	32	42
		(27.5)	(31.4)	(41.2)
Diagnosis
Controls	34 (33.3)	26.5%	26.5%	47.1%	0.3894
CD	38 (37.3)	34.2%	36.8%	29.0%
UC	30 (29.4)	20.0%	30.0%	50.0%
BMI > 30 (kg/m2)
Total	110	43	42	25
		(39.1)	(38.2)	(22.7)
Diagnosis
Controls	44 (40.0)	34.1%	38.6%	27.3%	0.8823
CD	36 (32.7)	41.7%	38.9%	19.4%
UC	30 (27.3)	43.3%	36.7%	20.0%

CD: Crohn’s disease; AA: African American; BMI: Body mass index; UC: Ulcerative colitis.

Table 6 Results of multivariate modelling with age, race, gender, body mass index and diagnosis as predictors of deficient, insufficient and sufficient vitamin D

	Full model		Global	Reduced model		Global
	OR	OR	P value (full)	OR	OR	P value (reduced)
	(95%CI),	(95%CI),		(95%CI),	(95%CI),
	deficient vs sufficient	insufficient vs sufficient		deficient vs sufficient	insufficient vs sufficient
Diagnosis			0.1482			0.0852
Controls	Ref.	Ref.		Ref.	Ref.
CD	1.71	2.11		2.22	2.16
	(0.74, 3.94)	(0.95, 4.69)		(1.07, 4.63)	(1.07, 4.36)
UC	0.73	1.13		0.92	1.2
	(0.30, 1.76)	(0.50, 2.53)		(0.42, 2.02)	(0.59, 2.48)
Gender			0.9584
Female	Ref.	Ref.
Male	0.9	0.95
	(0.46, 1.79)	(0.50, 1.81)
Age (yr)			0.1578
< 35	3.62	1.47
	(1.18, 11.12)	(0.56, 3.83)
35-49	1.9	0.68
	(0.68, 5.30)	(0.28, 1.63)
50-64	2.61	0.86
	(1.04, 6.58)	(0.40, 1.86)
> 65	Ref.	Ref.
Race			0.00061			< 0.00011
AA	Ref.	Ref.		Ref.	Ref.
White	0.251	0.67		0.231	0.64
	(0.13, 0.48)	(0.34, 1.29)		(0.12, 0.43)	(0.33, 1.22)
Other	0.3	0.68		0.18	0.57
	(0.03, 3.38)	(0.09, 4.89)		(0.02, 1.95)	(0.08, 3.96)
BMI (kg/m2)			0.00171			0.00301
< 25	0.68	0.57		0.71	0.63
	(0.32, 1.43)	(0.28, 1.17)		(0.34, 1.48)	(0.31, 1.26)
25-30	Ref.	Ref.		Ref.	Ref.
> 30	2.711	2.361		2.611	2.271
	(1.28, 5.73)	(1.17, 4.75)		(1.26, 5.42)	(1.14, 4.52)

¹Statistically significant. CD: Crohn’s disease; AA: African American; BMI: Body mass index; UC: Ulcerative colitis.