The Four Horsemen of the Apocalypse: Cancer, Depression, Vitamin D Deficiency, and Obesity: An Observational Study.

Objective. Studies aiming at illuminating the complex relationships between cancer, obesity, 25-hydroxy vitamin D (25-OHD) deficiency, and body fat percentage are ongoing. The objective of this study was to investigate the relationships between 25-OHD deficiency, visceral fat tissue, and the Beck Depression Inventory (BDI) in cancer patients. Methods. This study was conducted from 2013 to 2022. Patients' demographic data, such as age, sex, and body mass index (BMI), and laboratory parameters, including prealbumin, albumin, calcium, phosphorus, parathyroid hormone, 25-OHD, magnesium, hemoglobin, fat percentage, and C-reactive protein, were recorded. The Beck Depression Inventory was used to determine depression levels. Results. A total of 223 colon cancer patients aged 19–84 undergoing chemotherapy at our clinic were included in this prospective study. The male patients' mean BMI was 22.91 ± 3.74 kg/m2, whereas that of the female patients was 26.17 ± 3.75 kg/m2. The difference was statistically significant (p < 0.001). The mean total Beck Depression Inventory score was 13 ± 9. In this patient population, 105 (47.09%) patients had minimal depression, 69 (30.94%) had mild depression, 35 (15.70%) had moderate depression, and 14 (6.28%) had severe depression. The Beck Depression Inventory score was negatively and strongly associated with BMI and moderately and negatively associated with albumin levels. Conclusion. This study reveals a significant correlation between 25-OHD levels and the Beck Depression Inventory scores among cancer patients. We believe that 25-OHD levels may be used to determine the presence of depressive symptoms in cancer patients. However, further comprehensive multicentre studies are needed to draw more definitive conclusions. [ABSTRACT FROM AUTHOR]