Does Vitamin D Prevent Cancer?

The relationship between vitamin D and cancer has been discussed for a long time. Recently, it has become popular again with the increase in its use during the coronavirus disease period and the acceptance of its protective effect from infection. In addition to its different uses, many studies have been conducted on its cancer-protective effect, the need for vitamin D in patients with cancer and the ways of obtaining it. As a surgeon dealing with cancer surgery, I evaluated this patient group with a new perspective as a result of my clinical observations and came to the conclusion that vitamin D levels should definitely be evaluated in these patients.