A dose–response meta-analysis reveals an association between vitamin B12 and colorectal cancer risk. Issue 8 (16th September 2015)

• Record Type: Journal Article
• Authors: Sun, Nai-Hui; Huang, Xuan-Zhang; Wang, Shuai-Bo; Li, Yuan; Wang, Long-Yi; Wang, Hong-Chi; Zhang, Chang-Wang; Zhang, Cong; Liu, Hong-Peng; Wang, Zhen-Ning
• Is Part Of: Public health nutrition. Volume 19:Issue 8(2016)
• Page Start: 1446
• Page End: 1456
• Publication Date: 2015-09-16
• Subjects: Vitamin B12, -- Colorectal cancer, -- Meta-analysis; Nutrition -- Periodicals; Nutrition policy -- Periodicals; Public health -- Periodicals; 613.2
• DOI: 10.1017/S136898001500261X
• Languages: English
• ISSNs: 1368-9800

Abstract

Abstract: Objective: The current meta-analysis evaluated the association between vitamin B12 intake and blood vitamin B12 level and colorectal cancer (CRC) risk. Design: The PubMed and EMBASE databases were searched. A dose–response analysis was performed with generalized least squares regression, with the relative risk (RR) and 95 % CI as effect values. Setting: The meta-analysis included seventeen studies. Subjects: A total of 10 601 patients. Results: The non-linear dose–response relationship between total vitamin B12 intake and CRC risk was insignificant ( P =0·690), but the relationship between dietary vitamin B12 intake and CRC risk was significant ( P <0·001). Every 4·5 μg/d increment in total and dietary vitamin B12 intake was inversely associated with CRC risk (total intake: RR=0·963; 95 % CI 0·928, 0·999; dietary intake: RR=0·914; 95 % CI 0·856, 0·977). The inverse association between vitamin B12 intake and CRC risk was also significant when vitamin B12 intake was over a dosage threshold, enhancing the non-linear relationship. The non-linear dose–response relationship between blood vitamin B12 level and CRC risk was insignificant ( P =0·219). There was an insignificant association between every 150 pmol/l increment in blood vitamin B12 level and CRC risk (RR=1·023; 95 % CI 0·881, 1·187). Conclusions: Our meta-analysis indicates that evidence supports the use of vitamin B12 for cancer prevention, especially among populations with high-dose vitamin B12 intake, and that the association between CRC risk and total vitamin B12 intake is stronger than between CRC risk and dietary vitamin B12 intake only.