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

Table 4 Combined relative risk (RR)s and 95% confidence intervals of colorectal adenoma for the associations by sex, calcium intake, study region, and adenoma site

	Studies, n	Ref.	Combined RR (95%CI) comparing the highest vs the lowest categories	P for difference
Sex				0.30
Men	6	[13-15,20,27] and our study	0.78 (0.51-1.06)
Women	7	[14,15,20,23,27,37] and our study	0.58 (0.33-0.83)
Calcium intake				0.48
Low	7	[14,19,24-26,28] and our study	0.73 (0.46-1.01)
High	7	[14,19,24-26,28] and our study	0.61 (0.40-0.82)
Study region				0.88
United States	10	[19,21,23-30]	0.70 (0.52-0.88)
Asia	4	[13-15] and our study	0.66 (0.35-0.98)
Site				0.50
Distal adenoma	10	[13-15,21,23-25,27,28] and our study	0.67 (0.53-0.81)
Proximal adenoma	8	[13-15,21,25,28,37] and our study	0.61 (0.44-0.79)