Over a few decades a strong interlink between oxidative damage and cancer has been investigated by various scientists across the world on the basis of epidemiological observations of the effects of fruits and vegetables used in the diet for cancer patients. Primarily, Vitamin C, Vitamin D and Vitamin E are reported to be involved in the amelioration of side effects which occur in chemotherapy and radiation therapy of lungs, stomach, prostate, colorectal, gastric head and neck cancers. The vitamins acting as antioxidant adjuvants are found to have apoptotic and antiangiogenesis potential as well as inhibitory effects against metastasis in cancer cells. This chapter explicitly discusses the key aspects concerned with the vitamins in relation to cancer prevention and treatment. It describes vitamins and their natural resources, role of vitamins in the body, and vitamins as prime ingredients in the diet and their effects on cancer biology with reference to recent research reports. Moreover, this paper also includes the emerging potential of pharmaceutical advances to enhance bioavailability of the vitamins to cancer patients with improved safety and efficacy. Clinicians and researchers must mull over the nutritional requirements of individual cancer patient so as to treat cancer and increase life expectancy.