Colorectal cancer rates have been declining since the mid 1980s. That may be due in part because of regular screening through colonoscopy. However, scientists have previously found evidence that vitamin D could help protect against such tumors. (See our discussion below.)
What Is Driving Colorectal Cancer in Younger People?
One group has experienced a rapid increase in colorectal cancer. That is young adults under the age of 50. They have seen their incidence of this malignancy double since the 1990s. Investigators have speculated that diet, inflammation and disruption of the gut microbiome (called dysbiosis) could account for the rise, individually or together.
Could Vitamin D Help Prevent Colorectal Cancer?
A new study in the journal Gastroenterology suggests that lower levels of vitamin D may also play a role in the increased incidence of colorectal cancer (Gastroenterology, July 7, 2021). The researchers followed more than 90,000 women who have participated in the Nurses’ Health Study II. It began in 1989. Regular dietary surveys revealed how much vitamin D these volunteers got from their diet. The greater the intake of this nutrient, the lower the risk for developing colon polyps or early-onset colorectal cancer. The protection seemed clearer for women getting their vitamin D from foods such as oily fish, eggs and fortified dairy products than for those taking supplements.
The authors conclude:
“Our results further support that vitamin D may be important in younger adults for health and possibly colorectal cancer prevention.”
Earlier Hints of a Link Between Vitamin D and Colorectal Cancer:
An earlier study from Europe suggested that the higher your levels of vitamin D, the lower your risk of developing colorectal cancer (British Medical Journal, online Jan 22, 2010). The EPIC study, which stands for European Prospective Investigation into Cancer, enlisted over 500,000 adults from 10 countries. None of the subjects had cancer at the start of the study. Vitamin D levels were measured at that time.
After several years, 1,248 people had come down with colorectal cancer. The investigators matched them to 1,248 EPIC participants who were not diagnosed with cancer and compared the vitamin D levels. Those with the highest blood levels of this hormone at the start of the study were 40 percent less likely to have developed colorectal cancer.
From two studies, we have two different ways of answering the question, can vitamin D help protect people from colorectal cancer? Both blood level and dietary intake data strongly suggest that it can.
If you would like to know more about vitamin D, you may wish to read our eGuide to Vitamin D and Optimal Health. In this online resource, you can find information about where to find it and how much you might need, as well as symptoms of low vitamin D levels.