Brain tumors are a significant medical problem. This study aimed to assess the potential significance of DPYSL2, 8-OHdG, and LP-PLA2 in the oncological diagnosis of patients with brain tumors who have a vitamin D deficiency. To this end, we measured the concentrations of LP-PLA2, DPYSL2, and 8-OHdG in 62 patients with different types of brain tumors who exhibited vitamin D deficiency. No significant variations were observed that would enable the differentiation of different types of intracranial tumors. However, we found a correlation between the concentrations of LP-PLA2 and DPYSL2 and tumor size (in the GBM and brain metastases groups). Additionally, we found a correlation between Lp-PLA2 and DPYSL2 levels in patients with GBM and brain metastases. In the control group, we identified correlations between 8-OHdG and Lp-PLA2, as well as between vitamin D levels and 8-OHdG. Further research is needed to fully comprehend the examined issues.