. Author manuscript; available in PMC: 2019 Apr 1.

Published in final edited form as: Surg Oncol Clin N Am. 2017 Dec 15;27(2):243–267. doi: 10.1016/j.soc.2017.11.002

Table 5.

Characteristics of studies of vitamins and minerals and CRC

Study	Number of study participants	Age of participants	Follow-up years	CRC incidence	Analytic category	Analytical comparison, high versus low intake	Relative risk (95% CI)	Ref
Case-control	–	–	–	1,723 (Colon), 3,097 (Control)	Multiple vitamins	>5 years versus nerver or <1 year	Women-Colon cancer: 0.7 (0.4–1.3), p=0.03	Ref (⁸⁵)
					B-complex vitamins		Women-Colon cancer: 0.4 (0.2–0.7), p=0.0005
					Vitamin E		Women-Colon cancer: 0.6 (0.4–0.9), p=0.002
					Calcium		Women-Colon cancer: 0.4 (0.3–0.6), p<0.0001
					Iron		Women-Colon cancer: 0.6 (0.4–1.0), p=0.03
					Zinc		Women-Colon cancer: 0.4 (0.2–0.9), p=0.03
Case-control	–	–	–	2,349 (CRC), 4,168 (Control)	Vitamin B6	>5 mg/day versus <1 mg/day	Women-Rectal cancer: 3.57 (1.56–8.17), p=0.01	Ref (⁸⁸)
DCH	56,332 men and women	50–64	1993–2009	465 (Colon), 283 (Rectum)	Dietary folate	–	CRC: 0.83 (0.57–1.21), p=0.04	Ref (⁸⁹)
DCH	56,332 men and women	50–64	1993–2009	465 (Colon), 283 (Rectum)	Supplemental folate	–	CRC: 0.83(0.58–1.20), p=0.76	Ref (⁸⁹)