Vitamin D protects against colorectal cancer

Oct 31 2007

According to a new study by researchers at the U.S. National Cancer Institute (NCI) there is no link between vitamin D levels and the overall risk of dying from cancer.

However they say people with higher vitamin D levels are less likely to die from colorectal cancer.

Some research in animals and cell studies have suggested that a higher intake of vitamin D may offer protection from cancer and other diseases by reducing tumor growth and inducing cancer cell death.

The NCI research team set out to establish whether vitamin D can reduce a person's chances of dying from various types of cancer.

The team led by epidemiologist Dr. Michal Freedman tracked 16,818 people who joined a nationwide U.S. government health survey between 1988 and 1994, through to 2000 and found that 536 had died of cancer.

All the participants had provided blood samples which the researchers used to determine the level of vitamin D in their blood.

The researchers found that people with higher levels of vitamin D when they entered the study had an approximate 72 percent reduced risk of dying from colorectal cancer compared to those with the lowest levels of vitamin D.

But no link was found between vitamin D levels and the overall risk of dying from cancers such as lung, prostate, breast, non-Hodgkin lymphoma and leukemia.

Freedman says this was true for both men and women and racial and ethnic groups.

The body produces vitamin D when skin is exposed to sunlight, which is useful, as not many foods are naturally rich in it.

Vitamin D is found in fatty fish such as salmon, and milk is very often fortified with it.

Colorectal cancer is cancer that starts in the colon or rectum; it kills about 50,000 people each year in the U.S. alone.

Experts say that vitamin D is best known for strengthening bones and preventing rickets, a disease that causes soft, weak bones in children.

The National Cancer Institute is part of the U.S. National Institutes of Health.

The study is published in the Journal of the National Cancer Institute.