Sufficient 25-Hydroxyvitamin D Levels 2 Years after Colorectal Cancer Diagnosis are Associated with a Lower Risk of All-cause Mortality

Abstract

Background: Whether changes in 25 hydroxy vitamin D-3 (25 (OH)D-3) levels after colorectal cancer diagnosis influence clinical outcomes is unclear. We investigated the association of trajectories of 25(OH)D-3 levels with recurrence and all-cause mortality. Methods: In total, 679 patients were included in our data analyses. Trajectories of 25(OH)D-3 levels were defined on the basis of vitamin D status at diagnosis, at 6 months, and 2 years after diagnosis. Observed trajectories of 25(OH)D-3 levels were consistent deficient levels (20%), consistent sufficient levels (39%), increasing levels (20%), and a temporary drop in levels (13%). Associations of trajectories of 25(OH)D-3 with recurrence and all-cause mortality were assessed using multivariable Cox proportional hazards regression models. Results: During a follow-up time of 2.2 years for recurrence and 3.5 years for all-cause mortality, 31 and 65 events occurred, respectively. No statistically significant associations were observed for vitamin D trajectories and the risk of recurrence. Patients who were consistently sufficient compared with patients who were consistently deficient had a lower risk of all-cause mortality [HR 0.39; 95% confidence interval (CI), 0.21-0.73]. The risk of all-cause mortality seems lower in patients with increasing levels or a temporary drop in levels (HR 0.54; 95% CI, 0.27-1.10 and HR 0.40 95% CI, 0.17-0.93) relative to patients with consistent deficient levels. Conclusions: Patients with colorectal cancer following a trajectory characterized by sufficient levels of 25(OH)D-3 2 years after diagnosis all appeared to have a lower risk of all-cause mortality compared with patients having consistent deficient levels. Impact: Further studies should investigate how trajectories of 25(OH)D-3 levels are associated with colorectal cancer recurrence.