# Plasma 25-hydroxyvitamin D deficiency in the peri-operative period is associated with survival outcome in colorectal cancer patients: a meta-analysis

## TL;DR

Low vitamin D levels before and after surgery are linked to worse survival in colorectal cancer patients, with post-surgery levels being most critical.

## Contribution

This study is the first to meta-analyze the impact of peri-operative 25(OH)D deficiency on colorectal cancer survival outcomes.

## Key findings

- Peri-operative 25(OH)D deficiency was found in 59.61% of patients.
- Post-operative 25(OH)D deficiency was more strongly linked to short-term survival than pre-operative deficiency.
- Male gender, rectum tumors, and seasonal sampling were identified as risk factors for 25(OH)D deficiency.

## Abstract

Surgery had a significant impact on 25-hydroxyvitamin D (25-(OH)D) levels. Uncertainty still existed regarding the effects of peri-operative 25(OH)D deficiency on colorectal cancer (CRC) patients’ prognosis. The purpose of the present study was to explore the potential association between the peri-operative 25(OH)D deficiency and the survival outcome of CRC.

Seven electronic databases [including PubMed, EMBASE, Web of Science, The Cochrane Library, OvidMEDLINE(R), China National Knowledge Infrastructure (CNKI) and Wangfang data] were searched without language limitations. The primary outcomes were overall survival and all-cause mortality. Secondary outcomes were the incidence of 25(OH)D deficiency and risk variables for low 25(OH)D level in the peri-operative period.

14 eligible studies were obtained with 9324 patients for meta-analysis. In the peri-operative period, the pooled incidence of blood 25(OH)D deficiency was 59.61% (95% CI: 45.74–73.48). The incidence of blood 25(OH)D deficiency post-operatively (66.60%) was higher than that pre-operatively (52.65%, 95% CI: 32.94–72.36). Male (RR = 1.09, 95% CI: 1.03–1.16), rectum tumor (RR = 1.23, 95% CI: 1.03–1.47), spring and winter sampling (RR = 1.24, 95% CI: 1.02–1.49) were the risk factors for the 25(OH)D deficiency. The association between the low 25(OH)D post-operatively and short-term overall survival (HR = 0.43, 95% CI: 0.24–0.77) was most prominent, while a low 25(OH)D pre-operatively (HR = 0.47, 95% CI: 0.31–0.70) was more significantly associated with long-term all-cause mortality than that after surgery.

Peri-operative 25(OH)D impacted the CRC patients’ prognosis. Due to possible confounding effects of systemic inflammatory response (SIR), simultaneous measurement of vitamin D and SIR is essential for colorectal survival.

The online version contains supplementary material available at 10.1186/s12893-024-02473-5.