Vitamins, also known as vitamins, are commonly known as life-sustaining substances. These substances in the body neither constitute any body tissues nor are they a source of energy, but they are a class of organic substances necessary to maintain the body’s vital activities and are also important active substances for keeping the body healthy. Vitamins are found in small amounts in the body, but are indispensable. And because the body cannot synthesize vitamins or does not synthesize them in sufficient quantities, they must often be supplied by food. Vitamins are a huge family, and at this stage there are dozens of them known. Lack of vitamins may lead to many diseases. This article mainly focuses on the field of oncology to introduce several common vitamins and talk about the past life and present life of vitamins and tumors. 1. Science: Vitamin C directs oxidative death of specific mutated cancer cells Researchers found that high doses of vitamin C – about the equivalent of 300 oranges – in a cell culture environment and in mice can inhibit the growth of colorectal cancer caused by KRAS and BRAF mutations. Vitamin C, also called ascorbic acid, can be oxidized and converted to a new compound called dehydroascorbic acid (DHA) in oxygen-rich environments such as human arteries. In this study, the researchers found that once DHA enters the cell, the natural antioxidants inside the cancer cell will try to convert DHA back to ascorbic acid; this process depletes the antioxidants inside the tumor cell while causing the tumor cell to die due to oxidative stress. Vitamin D levels in the body are related to the prognosis of tumor patients Vitamin D enters the body and is first synthesized into 25 hydroxyvitamin D [25(OH)D] by the action of 25-hydroxylase in the liver, which is the main form of vitamin D stored in the body. Researchers found that higher blood vitamin D levels at the time of cancer diagnosis were associated with significantly better survival and remission rates. The results come from a comprehensive meta-analysis involving more than 17,000 cancer patients. Evidence from colorectal cancer, breast cancer and lymphoma all strongly support a protective effect of high levels of 25(OH)D in the blood at the time of diagnosis. Researchers have also observed limited but favorable evidence of a protective effect of high levels of 25(OH)D in patients with lung, stomach, prostate, leukemia, melanoma, and Merkel cell carcinoma. In addition, some studies have shown that plasma 25(OH)D predicts survival in patients with pancreatic cancer. Vitamin D deficiency is widespread worldwide, and formerly blood 25(OH)D concentration was commonly used internationally as a measure of vitamin D nutritional status in humans (>75 nM, adequate; 50-75 nM, deficient; <50 nM, extremely deficient). 25(OH)D levels also represent the total body stores of vitamin D. 3. Low levels of vitamin D predict high tumor risk Researchers found that the clinical study group (with low median levels of vitamin D) had a cancer incidence rate of 1020 cases per 100,000 people, higher than the prospective study group, which had a cancer incidence rate of 722 cases per 100,000 people. They also found that cancer incidence rates decreased as 25-hydroxyvitamin D levels rose; women with vitamin D levels of 40 ng/ml or higher had a 67% lower risk of cancer than women with vitamin D levels of 20 ng/ml or lower. In addition, the data suggest that for women of European ancestry, genetically, decreasing 25(OH)D concentrations are associated with a higher susceptibility to ovarian cancer. These findings suggest that increasing plasma vitamin D levels may reduce ovarian cancer risk. 4, vitamin A for colon cancer Scientists from EPFL recently identified an important signaling pathway that may be used to combat recurring colon cancer conditions. Treatment with vitamin A compounds that reactivate a gene that is turned off in cancer stem cells could help clear the cancer stem cells and prevent recurrence and metastasis from occurring. In a mouse model of colon cancer, treatment with vitamin A compounds blocked cancer progression and normalized tissue, in addition to removing cancer stem cells and preventing the development of metastasis. Researchers have found similar effects in patient samples.