Skip to content
My WebMD Sign In, Sign Up

Breast Cancer Health Center

Font Size

Vitamin D Deficiency Worsens Breast Cancer?

Inadequate Levels of Vitamin D Linked to Sharply Increased Odds of Cancer Spread, Death

Vitamin D Deficiency Linked to Poor Breast Cancer Prognosis continued...

But there was a point above which there seemed to be too much of a good thing, Goodwin says. If vitamin D blood levels were too high, the risk of dying appeared to rise, although the number of women with very high levels was so small that the finding could be due to chance.

"Our concern is that women may think, if some is good, more must be better, and increase vitamin D intake beyond what's optimal," she says.

So just what is optimal? A reading of 80 to 120 nanomoles per liter, according to Goodwin. That range has also been shown to be optimal for bone and heart health, she says.

Vitamin D Testing

If you don't know your vitamin D level, you're not alone: Doctors don't routinely order it as part of the blood tests taken for an annual physical, Goodwin says.

Julie Gralow, MD, chairwoman of ASCO's Cancer Communications Committee and associate professor of medicine at the University of Washington in Seattle, suggests that women with breast cancer take the initiative and ask about having their vitamin D levels measured.

"We now have a reliable test, and we know to safely correct deficiencies," she tells WebMD.

Goodwin says there is evidence to suggest that for women with a deficiency, taking 800 international units (IU) of vitamin D a day can raise levels to the optimal range.

For healthy people without a deficiency, current recommendations call for people between ages 0-50 to get 200 IU of vitamin D daily, with 400 IU recommended for those between the ages of 51 and 70. After age 70, 600 IU of vitamin D are recommended each day.

Goodwin and colleagues are now trying to confirm the findings in a second, similar study; results are due by the end of the year. If confirmed, the next step will be a study to determine whether giving supplements actually lowers the risk of recurrence and death in women with breast cancer.

The research was funded by the Breast Cancer Research Foundation.

1|2

Today on WebMD

Breast Cancer Overview
From self-exams and biopsies to reconstruction, we’ve got you covered.
Dealing with breast cancer
Get answers to your questions.
 
woman having mammogram
Experts don’t agree on all fronts, but you can be your own advocate.
woman undergoing breast cancer test
Many women worry. But the truth? Most abnormalities aren’t breast cancer.
 
Breast Cancer Treatments Improving
VIDEO
Resolved To Quit Smoking
SLIDESHOW
 
Woman getting mammogram
Article
Screening Tests for Women
SLIDESHOW
 
ovarian cancer overview slideshow
SLIDESHOW
serious woman
Article
 
what is your cancer risk
HEALTH CHECK
10 Ways to Revitalize Slideshow
SLIDESHOW