Women with breast cancer should be given high doses of vitamin D because a majority of them are likely to have low levels of vitamin D, which could contribute to decreased bone mass and greater risk of fractures, according to scientists at the University of Rochester Medical Center.
In a study of 166 women undergoing treatment for breast cancer, nearly 70 percent had low levels of vitamin D in their blood, according to a study being presented Thursday, Oct. 8, at the American Society of Clinical Oncology's Breast Cancer Symposium in San Francisco. The analysis showed women with late-stage disease and non-Caucasian women had even lower levels.
"Vitamin D is essential to maintaining bone health, and women with breast cancer have accelerated bone loss due to the nature of hormone therapy and chemotherapy. It's important for women and their doctors to work together to boost their vitamin D intake," said Luke Peppone, Ph.D., research assistant professor of Radiation Oncology, at Rochester's James P. Wilmot Cancer Center. He is a member of the National Cancer Institute's Community Clinical Oncology Program research base in Rochester.
Scientists funded by the NCI analyzed vitamin D levels in each woman, and the average level was 27 nanograms per milliliter; more than two-thirds of the women had vitamin deficiency. Weekly supplementation with high doses of vitamin D -- 50,000 international units or more -- improved the levels, according to Peppone's study.
The U.S. Institute of Medicine suggests that blood levels nearing 32 nanograms per milliliter are adequate.
This problem is not unexpected, Peppone said, because previous studies have shown that nearly half of all men and women are deficient in the nutrient, with vitamin D levels below 32 nanograms per milliliter. Vitamin D, obtained from milk, fortified cereals and exposure to sunlight, is well known to play an essential role in cell growth, in boosting the body's immune system and in strengthening bones.