In this multi-institutional cohort of 2809 patients with inflammatory bowel disease, almost one-third had deficient levels of vitamin D (<20 ng/mL).
In a median follow-up period of 11 years, 7% (n = 196) of patients in the study developed cancer, with 41 cases of colorectal cancer. Patients with vitamin D deficiency had an increased risk of cancer (adjusted OR, 1.82; 95% CI, 1.25–2.65).
The authors conclude that vitamin D deficiency is associated with a greater risk of all cancer, but especially colorectal cancer.
The study has significant limitations, well outlined by the authors, and interventional studies of Vitamin D supplementation in IBD patients are yet to be done, but their bottom line recommendation that patients with inflammatory bowel disease should be screened routinely for Vitamin D deficiency appears to be valid.
Full text is open access.
Association Between Reduced Plasma 25-Hydroxy Vitamin D and Increased Risk of Cancer in Patients With Inflammatory Bowel Diseases
Ashwin N. Ananthakrishnan, Su–Chun Cheng, Tianxi Cai, Andrew Cagan, Vivian S. Gainer, Peter Szolovits, Stanley Y. Shaw, Susanne Churchill, Elizabeth W. Karlson, Shawn N. Murphy, Isaac Kohane, Katherine P. Liao
Clin. Gastroenterol. Hepatol. 2014 May 01;12(5)821-827
BACKGROUND & AIMS
Vitamin D deficiency is common among patients with inflammatory bowel diseases (IBD) (Crohn’s disease or ulcerative colitis). The effects of low plasma 25-hydroxy vitamin D (25[OH]D) on outcomes other than bone health are understudied in patients with IBD. We examined the association between plasma level of 25(OH)D and risk of cancers in patients with IBD.
From a multi-institutional cohort of patients with IBD, we identified those with at least 1 measurement of plasma 25(OH)D. The primary outcome was development of any cancer. We examined the association between plasma 25(OH)D and risk of specific subtypes of cancer, adjusting for potential confounders in a multivariate regression model.
We analyzed data from 2809 patients with IBD and a median plasma level of 25(OH)D of 26 ng/mL. Nearly one-third had deficient levels of vitamin D (<20 ng/mL). During a median follow-up period of 11 years, 196 patients (7%) developed cancer, excluding nonmelanoma skin cancer (41 cases of colorectal cancer). Patients with vitamin D deficiency had an increased risk of cancer (adjusted odds ratio, 1.82; 95% confidence interval, 1.25-2.65) compared with those with sufficient levels. Each 1-ng/mL increase in plasma 25(OH)D was associated with an 8% reduction in risk of colorectal cancer (odds ratio, 0.92; 95% confidence interval, 0.88-0.96). A weaker inverse association was also identified for lung cancer.
In a large multi-institutional IBD cohort, a low plasma level of 25(OH)D was associated with an increased risk of cancer, especially colorectal cancer.
Link to full text: www.cghjournal.org/article/S1542-3565(13)01644-3/fulltext