Circulating vitamin D and colorectal cancer risk: An international pooling project of 17 cohorts
Journal of the National Cancer Institute Mar 06, 2019
McCullough ML, et al. - Researchers investigated the protective function of vitamin D in colorectal carcinogenesis via analysis of experimental and epidemiological studies. Overall, they noted a link between elevated circulating 25(OH)D levels and statistically important, substantially lower colorectal cancer risk in women—as well as a non-statistically significant lower risk in men. They observed higher optimal 25(OH)D concentrations for colorectal cancer risk reduction (75-100 nmol/L) than the current Institute of Medicine (IOM) recommendations.
Methods
- The study sample consisted of 5,706 patients with colorectal cancer and 7,107 healthy control individuals with a wide range of circulating 25(OH)D concentrations.
- 25(OH)D levels were recalculated for 30.1% of participants.
- They calibrated previously measured 25(OH)D to the same assay to permit the estimating risk by absolute concentrations.
- They calculated study-specific relative risks (RRs) for prediagnostic season-standardized 25(OH)D levels via conditional logistic regression, and were pooled using random effects models.
Results
- They observed an association of deficient 25(OH)D (< 30 nmol/L) with 31% greater colorectal cancer risk; 25(OH)D above sufficiency (75 to < 87.5 and 87.5 to < 100 nmol/L) with 19% greater cancer risk; and 27% lower risk when compared with the lower range of sufficiency for bone health (50 to < 62.5 nmol/L), respectively.
- They did not identify a continuous decline in the risk at 25(OH)D of ≥ 100 nmol/L.
- When adjusting for body mass index, physical activity, or other risk factors, there was little impact on the associations.
- They reported 19% lower colorectal cancer risk in women and 7% lower in men for each 25 nmol/L increment in circulating 25(OH)D.
- Overall, inverse associations in all subgroups—including colorectal subsite, geographic area, and season of blood collection—were evident.
Only Doctors with an M3 India account can read this article. Sign up for free or login with your existing account.
4 reasons why Doctors love M3 India
-
Exclusive Write-ups & Webinars by KOLs
-
Daily Quiz by specialty
-
Paid Market Research Surveys
-
Case discussions, News & Journals' summaries