Determination of serum vitamin D in patients with renal, bladder, and prostate cancer by ultra-performance liquid chromatography-tandem mass spectrometry.

The purpose of this study is to detect the vitamin D (VitD) levels in patients with renal cell carcinoma (RCC), bladder cancer (BC), and prostate cancer (PC) using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technology to assess the VitD status in subjects using different methods, to understand the true level of VitD in RCC, BC, and PC patients. A total of 170 subjects were included in this study, and their serum VitD metabolite levels were measured, including 25-hydroxyvitamin D2 [25(OH)D2], 25-hydroxyvitamin D3 [25(OH)D3], 3-epi-25-hydroxyvitamin D3 [C3-epi-25(OH)D3, C3-epi], and calculations for 25(OH)D, 25(OH)D2/25(OH)D3, and C3-epi/25(OH)D3 were made. The variations in serum VitD, calcium (Ca), inorganic phosphorus (IP), vitamin D receptor (VDR), and renal function indicators were measured, and their correlations were analyzed. The levels of 25(OH)D, 25(OH)D3, C3-epi, C3-epi /25(OH)D3, and free 25(OH)D [ F25(OH)D] in RCC, BC, and PC patients were significantly lower than that in the healthy control (HC) group (all p<0.05). The ratio of 25(OH)D2/25(OH)D3 was significantly higher in these groups compared to the HC group (all p<0.05). 25(OH)D3 distinguished the HC group from common cancers of the urinary system (including RCC, BC, and PC) in male patients and showed good diagnostic performance. The level of 25(OH)D3 in all three groups was positively correlated with F25(OH)D levels, and in the disease groups, C3-epi levels were positively correlated with both 25(OH)D3 and F25(OH)D levels. This study found that RCC, BC, and PC patients had lower serum levels of 25(OH)D3, C3-epi, and F25(OH)D compared to healthy individuals, with most RCC, BC, and PC patients displaying VitD deficiency.