A pair of studies presented at the American Association for Cancer Research
(AACR) in April 2006 found that women who consume higher amounts of vitamin D
reduce their risk of developing breast cancer. Yet most women get only about
one-third of the recommended daily intake of vitamin D. (Has your doctor told
you to take more Vitamin D? Share your thoughts in our natural health community
forum.)
The first study found that women who consumed the highest levels of vitamin D
were 50 percent less likely to develop breast cancer compared to those who did
not get the minimum recommended daily intake of vitamin D. The study also showed
that even moderate levels of vitamin D resulted in 10 percent less risk. This
would translate to 20,000 fewer cases a year if it were true of all American
women.
The second study found that women who spent time outdoors as adults and took
vitamin D through food or supplements--especially during their adolescent
years--reduced their chances of breast cancer later in life by 25 percent to 45
percent. Those without breast cancer were less likely to cover up whenever they
were outside, were more likely to get dietary sources of vitamin D or had
regularly consumed cod liver oil, which is rich in vitamin D.
Who's At Risk For Breast Cancer?
Breast cancer is the most common cancer among women, except for skin cancer.
It is the second leading cause of cancer death in women, after lung cancer.
The American Cancer Society estimates that in 2006 about 212,920 women in the
United States will be diagnosed with invasive breast cancer and that
approximately 40,970 women will die from the disease. The chance of a woman
having invasive breast cancer some time during her life is about 1 in 8. The
chance of a woman dying from breast cancer is about 1 in 33.
Breast cancer death rates tend to be higher in areas with low winter sunlight
and lower in sunny areas. If you live north of the line connecting San Francisco
to Philadelphia, odds are you don't get enough vitamin D. The same holds true if
you don't get outside for at least 15 minutes per day, even if it's just to sit
on the stoop or take a short walk.
Why Vitamin D?
Aside from building strong bones, vitamin D seems to play a role in the way
cancer develops. Vitamin D appears to reduce the incidence of many types of
cancer by inhibiting angiogenesis--the formation of new blood vessels that are
essential for tumor growth--and by inhibiting the division of epithelial cells
that line the breast.
Because few foods are good natural sources of vitamin D, most vitamin D comes
from fortified foods such as dairy products, breakfast cereals and orange juice.
The rest comes from dietary supplements and sun exposure, which triggers the
skin to produce vitamin D.
Is That Enough?
Nope. Most Americans get only 320 IU per day of vitamin D from foods.
According to the research presented at the AACR, a woman would have to consume
more than 2700 IU per day to reduce her cancer risk by 50 percent! Supplements
typically contain only 400 IU.
That's where the sunshine comes in.
Researchers estimate that sunning yourself long enough to just 'turn pink'
can produce the equivalent of 10,000-25,000 IU of oral vitamin D. According to
Michael Holick, M.D. of Boston University Medical School, "Five to 10 minutes in
the sun 2 to 3 times a week is more than adequate to satisfy your vitamin D
requirements."
But Holick also adds a caveat. "After 5 to 10 minutes of exposure, put on a
sunscreen of SPF 15 or greater for the rest of your time in the sun."
Revolution Health Group
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