Vitamin D deficiency and malignancies

The analysis of domestic and foreign literature shows that oncological diseases are most often accompanied by a low level of 25(OH)D in the blood serum of patients and a high prevalence of deficiency and severe deficiency of vitamin D. It can be confidently stated that the level of 25(OH)D in serum blood of oncological patients, on average, is lower than in healthy people of the corresponding sex and age. In this regard, statistical studies were carried out, which demonstrated the prevalence of vitamin D deficiency in the countries of Europe and North America, which is directly proportional to the level of annual mortality from cancer and the probability of death from cancer, any type of cardiovascular disease, diabetes and chronic respiratory diseases, and this relationship is statistically significant (p < 0.001). Oncological morbidity and mortality from cancer in the Russian Federation naturally increases especially in higher latitudes, which, along with other reasons, is associated with a limitation in the duration of the effective production of vitamin D3 in human skin under the influence of ultraviolet radiation. Some clinical studies of vitamin D supplementation as a therapeutic agent are showing measurable positive results in cancer, with far more positive than in placebo groups. However, negative results that are harmful to patients participating in clinical experiments have not been established in the study of many hundreds of studied articles on this issue. The most commonly seen beneficial effects of vitamin D supplementation have been in the treatment of breast and colorectal cancer, which are particularly noticeable in patients with low baseline serum levels of 25(OH)D and high daily doses of 25(OH)D3 supplementation well above standard recommendations of 400–800 IU daily. Due to the high prevalence of vitamin D deficiency among cancer patients, taking into account international positive experience, it seems very useful and necessary to create domestic scientific foundations and expand the clinical practice of using vitamin D supplements as a therapeutic agent for cancer.