Vitamin D helps prevent breast cancer

An ounce of prevention
"Clinical trials are being held to determine the effects of vitamin D supplements," says Knight. If the results are good, you could be getting your sunshine drug in pill form.

In addition to vitamin D, Knight recommends a healthy lifestyle to prevent breast cancer. "Exercise and maintaining body weight have been shown to help all forms of cancer," she says. "We also know that diet is a factor in cancer prevention but we don't yet know what components of diet are beneficial."

Knight says it's still important to talk to your physician before making lifestyle changes. "I wouldn't suggest taking or doing anything without talking to your doctor."

Nothing but a number
In the Mount Sinai study, women who worked an outdoor job (physical activity wasn't calculated), took cod liver oil, ate fish and drank milk between the ages of 10-19 and the ages of 20-29 were found to have significantly reduced breast cancer risk (between 25 and 40 per cent).

But it's not too late for women in their 30s and older.

"The results for older women didn't show as significant results but increasing vitamin D can still be beneficial," says Knight. "Nothing can guarantee you won't get breast cancer. There are too many different factors that contribute to the disease. But doing something positive for your health is never bad."