Vitamin D levels inversely associated with incident colon cancer

January 01, 0001

Vitamin D levels inversely associated with incident colon cancer

The health benefits of vitamin D have recently been getting a lot of attention. This large group of European researchers examined the association between circulating vitamin D levels, dietary intake of calcium and vitamin D, and the risk of colorectal cancer using a nested case-control study. This research was performed within the EPIC study, a cohort of more than 520,000 participants from 10 western European countries. Of this large population, 1248 cases of incident colorectal cancer were identified and matched to 1248 controls. Vitamin D concentrations (25-hydroxy-vitamin-D, 25- (OH)D) were measured by enzyme immunoassay. Dietary data were garnered from questionnaires. Incidence rate ratios were calculated using multivariate conditional logistic regression models, with adjustment for potential confounders.

The researchers found: "25-(OH)D concentration showed a strong inverse linear dose-response association with risk of colorectal cancer. Compared with a pre-defined mid-level concentration of 25-(OH)D (50.0-75.0 nmol/l), lower levels were associated with higher colorectal cancer risk (less than 25.0 nmol/l incidence rate ratio 1.32, 25.0-49.9 nmol/l 1.28), and higher concentrations associated with lower risk (75.0-99.9 nmol/l 0.88, 100.0 nmol/l 0.77). In analyses by quintile of 25-(OH)D concentration, patients in the highest quintile had a 40% lower risk of colorectal cancer than did those in the lowest quintile. Subgroup analyses showed a strong association for colon but not rectal cancer. Greater dietary intake of calcium was associated with a lower colorectal cancer risk. Dietary vitamin D was not associated with disease risk. Findings did not vary by sex and were not altered by corrections for season or month of blood donation."

The authors concluded: "The results of this large observational study indicate a strong inverse association between levels of pre-diagnostic 25-(OH)D concentration and risk of colorectal cancer in western European populations. Further randomised trials are needed to assess whether increases in circulating 25-(OH)D concentration can effectively decrease the risk of colorectal cancer."

This study provides further evidence for the importance of adequate vitamin D intake/production, specifically regarding colorectal cancer, and does so in a broad population of patients

For the full abstract, click here.

BMJ 340:b5500, 21 January 2010 © 2010 Jenab et al.
Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations- a nested case-control study. Mazda Jenab, H Bas Bueno-de-Mesquita, Pietro Ferrari, et al. Correspondence to M Jenab: [email protected]

Category: D. Digestive, T. Endocrine/Metabolic/Nutritional. Keywords: vitamin D, 25-(OH)D, calcium, dietary intake, colon cancer, colorectal cancer, case-control study, journal watch.
Synopsis edited by Dr Paul Schaefer, Toledo, Ohio. Posted on Global Family Doctor 26 March 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.