More often than not it seems something new is added to the already long list of things that cause cancer, but health experts want Canadians to know about a new recommendation that's been proven to reduce the risk of developing certain types of the disease.

The Canadian Cancer Society urges all adults to take 1,000 international units of vitamin D daily during fall and winter. It's basing its new findings on growing evidence that links the vitamin to reduced risk for colorectal, breast and prostate cancers.

"The evidence is still growing in this area, but we want to give guidance to Canadians about this emerging area of cancer prevention based on what we know now," says Heather Logan from the Canadian Cancer Society. "As we find out more we will update our recommendation."

In addition to the advice, a new study released in the U.S. on Friday found that taking a supplement and calcium substantially reduces all cancer risk in post-menopausal women. Specifically, the researchers found that the higher the levels of vitamin D in the blood, the lower the relative risk of developing cancer. Another study released in May, suggests that women who consume more calcium and vitamin D may be less likely to develop breast cancer before menopause.

Besides taking supplements, people can also get vitamin D by exposure to sunlight and in their diets. However, Logan cautions Canadians about relying too much on getting it through the harmful rays of Old Sol. "It's important to remember that a few minutes a day of unprotected sun exposure is usually all that is needed for some people to get enough Vitamin D," she said. "It's not a good idea to rely solely on the sun to obtain vitamin D. For some people, it's possible that just a few minutes of unprotected sun exposure every day could increase skin cancer risk."

The Society is not changing its SunSense guidelines, as skin cancer is the most frequently diagnosed cancer in Canada. In fact, it recommends that people stay out of the sun between 11am and 4pm when its rays are the strongest. Use a sunscreen with a protection factor of SPF 15 or higher and SPF 30 if you work outdoors or plan to be outside for most of the day.

If you're light-skinned the Society recommends you take 1,000 IUs during fall and winter. While elderly and dark-skinned people should take it all year long.