Abstract
BACKGROUND: Low vitamin D status and inflammation are associated with poor prognosis among colorectal cancer (CRC) patients. We assessed the efficacy of personalized vitamin D(3) supplementation (VIDS) for reducing inflammation in patients with low vitamin D status. METHODS: In an ongoing randomized double-blind, placebo-controlled trial in Germany, CRC patients who underwent surgery in the past year and had serum 25-hydroxyvitamin D levels < 60 nmol/L were randomly assigned to either a personalized loading dose of VIDS, followed by a maintenance dose of 2000 IU/day or a placebo for 12 weeks. Changes in serum interleukin-6 (IL-6), interferon-gamma (IFN-γ), and matrix metalloproteinase (MMP-1) were compared at the end of trial among 126 patients (65 in the placebo and 61 in the intervention group). RESULTS: The VIDS group exhibited 39.3% reduction in IL-6 levels compared to the placebo group (95% CI: -54.9% to -18.2%; p = 0.001). The reductions observed in IFN-γ and MMP-1 due to VIDS were not statistically significant (-6.7%; p = 0.69 and -5.4%; p = 0.23, respectively). CONCLUSION: In CRC patients with low vitamin D status, VIDS reduces serum IL-6, a pro-inflammatory biomarker associated with poor prognosis. Further research should explore a potential supportive therapeutic role of VIDS in managing inflammation and improving CRC outcomes. [Words: 200].