ObjectiveTo explore the correlation of BMI and 25 hydroxyvitamin D3 level with colon cancer.MethodsA total of 100 cases who underwent colonoscopy and were excluded from bowel diseases at the physical examination center of the First Hospital of Qinhuangdao from March 2017 to October 2017 were retrospectively selected as the control group. A total of 100 patients who underwent colonoscopy at general surgery or physical examination center and were confirmed to have colon cancer by pathological examination were included in the colon cancer group. The height, weight and body mass index (BMI) were measured in the morning, and the level of 25 hydroxyvitamin D3 (25(OH)D3) was determined by fasting blood sampling.Results① There was no statistical significance in age and 25(OH)D3 level between the two groups (P>0.05), and BMI of the colon cancer group was significantly higher than that of the control group (P<0.05). ② The proportion of overweight and obesity in the colon cancer group was significantly higher than that in the control group (P<0.05), and the proportion of vitamin D deficiency was significantly higher as well (P<0.05). ③ Logistic regression analysis showed that the incidence of colon cancer in patients with vitamin D deficiency was 12.263 times higher than that in patients without vitamin D deficiency, and the incidence of colon cancer in patients with overweight and obesity was 2.215 times higher than that in patients with normal BMI, with statistically significant differences (P<0.05).ConclusionThe incidence of colon cancer in patients with vitamin D deficiency and those with BMI of overweight or obesity is significantly increased.