Circulating levels of vitamin D and colorectal adenoma: A case-control study and a meta-analysis

Table 3 Included studies of circulating levels of 25-hydroxyvitamin D and colorectal adenoma

First author, year	Country (sex)	Study design	study dates	Endpoint	Type of endoscopy	25(OH)D, mean or median	No. of cases/controls	25(OH)D levels in the highest vs lowest categories	OR (95%Cl)
Platz, 2000	United States (W)	Prospective study	1989-1996	First adenoma	Sigmoidoscopy or colonoscopy	26.4 in cases and 26.8 ng/mL in controls, mean	326/326	38.0 ng/mL vs 16.3 ng/mL, median	1.00 (ref), 0.64, 0.58, 1.04 (0.66-1.66)
Levine, 2001	United States (M, W)	Case-control study	1991-1993	First adenoma	Sigmoidoscopy	25.6 in cases and 26.9 ng/mL in controls, mean	473/506	34.3-115 ng/mL vs 1-15.2 ng/mL, range	1.00 (ref), 0.99, 0.86, 0.74 (0.51-1.09)
Peters, 2001	United States (M, W)	Case-control study	1994-1996	First (61%) or recurrent adenoma	Colonoscopy (86.2%) or sigmoidoscopy	24.7 in cases and 26.5 ng/mL in controls, median	236/218	33.7-67.2 ng/mL vs 5.3-19.4 ng/mL, range	1.0(ref), 0.40, 0.67, 0.47, 0.43(0.23-0.81)
Grau, 2003	United States (M, W)	Prospective study	1992-1996	Recurrent adenoma	Colonoscopy	29.1 ng/mL, median	376/422	-	0.99 (0.91-1.07) OR for serum vitD levels per 12 (1SD) units increase
Peters, 2004	United States (M, W)	Prospective study	1993-1999	First advanced adenoma	Sigmoidoscopy	27.0 in cases and 28.3 ng/mL in controls, mean	394/397	-	0.87 (0.75-1.01) OR for serum vitD levels per 10 units increase.
Miller, 2007	United States (M, W)	Cross-sectional study	1998-2000	First adenoma	Colonoscopy	27.5 in cases and 31.4 ng/mL in controls, mean	111/238	> 33.8 ng/mL vs < 20.8 ng/mL, range	1.00 (ref), 0.74, 0.51 (0.27-0.98)
Takahashi, 2010	Japan (M)	Case-control study	1997-2004	First adenoma	Colonoscopy	26.2 in cases and 26.1 ng/mL in controls, mean	656/648	≥ 30 ng/mL vs < 22 ng/ml, range	1.00 (ref), 1.21, 1.21, 1.25 (0.85-1.84)
Fedirko, 2010	United States (M, W)	Pooled case-control study	1991-2002	First adenoma	Colonoscopy	24.5 in cases and 25.5 ng/mL in controls, mean	616/770		1.00 (ref), 0.77, 0.85, 0.59 (0.41-0.84)
Adams, 2011	United States (M, W)	Cross-sectional study	1998- 2003	Fitst or recurrent adenoma	Colonoscopy	23.1 in cases and 24.9 ng/mL in controls, mean	149/ 225	> 28.9 ng/mL vs ≤ 20.5 ng/ml, range	1.00 (ref), 0.97, 0.71 (0.38-1.30)
Ashktorab, 2011	United States (M, W)	Case-control study			Colonoscopy	41.2 in cases and 41.4 ng/mL in controls, mean	93/187	> 57.7 ng/mL vs < 29.5 ng/mL, range	1.00 (ref), 1.4, 1.9, 0.6 (0.3-1.4)
Hong, 2012	Korea (M, W)	Case-control study	2009-2010	First adenoma	Colonoscopy	20.0 in cases and 25.0 ng/mL in controls, mean	143/ 143	≥ 23.9 ng/mL vs < 14.3 ng/mL, range	1.00 (ref), 0.87, 0.40, 0.38 (0.18-0.80)
Yamaji, 2012	Japan (M,W)	Cross-sectional study	2004-2005	First adenoma	Colonoscopy		737/ 703	32 ng/mL vs 16 ng/mL, median	1.00 (ref), 0.86, 0.91, 1.03, 0.64 (0.45-0.92)
Jacobs, 2013	United States (M, W)	Prospective study	1990-1999	Recurrent adenoma	Colonoscopy		942/ 1132	> 30 ng/mL vs < 20 ng/mL, range	1.00 (ref), 0.91, 0.95 (0.73-1.24)
Aigner, 2014	Austria (W)	Cross-sectional study	2010-2013	First adenoma	Colonoscopy	22.8 ng/mL in women	90/629		0.976 (0.954-0.999) for 1 ng/mL increment
Choi, 2015 (our study)	Korea (M, W)	Case-control study	2011-2012	First or recurrent(5%) adenoma	Colonoscopy	15.7 ng/mL in cases and 16.6 in controls	112/112	23.4 ng/mL vs 10.0 ng/mL, mean	1.00 (ref), 0.72, 0.73, 0.49 (0.19-1.27)