Aim: Vitamin D has a role in carcinogenesis and may have effect on recurrence. Thus, we aim to analyze the prognostic effect of vitamin D levels at beginning and follow-up together with the contribution of vitamin D supplementation on patients with colorectal cancer (CRC). Materials & methods: CRC patients who underwent curative surgery were included. Patients' vitamin D values were assessed under four groups according to baseline and follow-up vitamin D values, and whether vitamin D supplementation was used. Survival distributions were compared for vitamin D groups. Results: Patients with a high follow-up vitamin D level and a high vitamin D level after supplementation presented with better disease-free survival and overall survival than patients with low vitamin D and low vitamin D levels after supplementation. Conclusion: Follow-up vitamin D values seems to be a good predictive biomarker and vitamin D supplementation may have a positive effect on survival.
Keywords: colorectal cancers; predict; prognosis; recurrence; supplementation; vitamin D.