Effects of vitamin D supplementation on inflammatory response in patients with cancer and precancerous lesions: systematic review and meta-analysis of randomized trials.

Abstract

Abstract Purpose Inflammation plays a key role in tumor development and progression. Vitamin D has potential tumor suppressing effects through modulation of inflammatory processes. The aim of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to summarize and evaluate the effects of vitamin D3 supplementation (VID3S) on serum inflammatory biomarkers among patients with cancer or pre-cancerous lesions (PROSPERO Reg #: CRD42022295694). Methods We searched PubMed, Web of Science and Cochrane databases until November 2022. The effects of VID3S were estimated from pooled standardized mean differences (SMDs) with their 95% confidence intervals (CIs) for inflammatory biomarker follow-up levels between intervention and control groups. The study was conducted according to the PRISMA guidelines and quality assessment of included studies was conducted using the Cochrane Risk of Bias tool. Results Eight RCTs with a total of 592 patients who had cancer or pre-cancerous conditions were included in the meta-analyses. VID3S significantly lowered serum levels of tumor necrosis factor (TNF)-α [SMD (95%CI): -1.65 (-3.07; -0.24)]. VID3S also reduced serum levels of interleukin (IL)-6 and C-reactive protein (CRP) but the effects did not reach statistical significance [SMD (95%CI): -0.83 (-1.78; 0.13) and − 0.09 (-0.35; 0.16), respectively]. VID3S did not have any effect on IL-10 serum levels [SMD (95%CI): 0.00 (-0.50; 0.49)]. Conclusions Our study shows evidence of a significant reduction of TNF-α levels by VID3S for patients with cancer or precancerous lesions. Patients with cancer or precancerous lesions may benefit from personalized VID3S in suppressing tumour-promoting inflammatory response.