Many colorectal cancers are thought to arise from adenomatous polyps in the colon. These mushroom-shaped growths are usually benign, but some may develop into cancer over time. Symptoms can include blood in the stool, narrower stools, a change in bowel habits and general stomach discomfort. However, you may not have symptoms at first, so screening is important. Everyone who is 50 or older should be screened for colorectal cancer. Colonoscopy is one method that your doctor can use to screen for colorectal cancer. Treatments for colorectal cancer include surgery, chemotherapy, radiation or a combination of treatments.
Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced endogenously when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. Vitamin D is essential for promoting calcium absorption in the gut and maintaining adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and prevent hypocalcemic tetany.
A study published in the British Medical Journal examined the association between circulating vitamin D concentration, dietary intake of vitamin D and calcium, and the risk of colorectal cancer. This nested case-control study involved 1,248 cases of colorectal cancer and 1,248 matched control. The results were patients in the highest quintile of vitamin D levels had a 40% lower risk of colorectal cancer than did those in the lowest quintile. Greater intake of calcium was found to be associated with a lower risk of colorectal cancer. Supplementation with vitamin D was not found to be associated with disease risk. In conclusion these findings suggest a strong inverse association between higher vitamin D levels and reduced risk of colorectal cancer. The authors stated “Further randomized trials are needed to assess whether increases in circulating 25-(OH)D concentration can effectively decrease the risk of colorectal cancer.”1
1 Jenab M, Bueno-deMesquita HB, Ferrari P, et al. Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations:a nested case-control study. BMJ. Jan2011.