You are here: Home / About Us / News and Media / 2008 News / Toronto researcher reveals vitamin D deficiency associated with breast cancer

Toronto researcher reveals vitamin D deficiency associated with breast cancer

May 14, 2008 – In a study released by the American Society of Clinical Oncology, clinician-scientist Dr. Pamela Goodwin has uncovered a link between vitamin D deficiency and poor prognosis of breast cancer.

Dr. Goodwin, a Senior Investigator at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital, found that deficiency in vitamin D is common in breast cancer patients and is associated with higher grade breast cancer tumours. Patients with vitamin D deficiency also had an increased risk of recurrence and lower overall survival rates than those patients with sufficient vitamin D levels.

“Breast cancer is still the most common cancer among Canadian women,” states Dr. Goodwin. “This research helps us to identify a correlation between vitamin D levels in breast cancer patients and encourages us to seek further knowledge.” Vitamin D helps to regulate cell growth and differentiation, offsetting cancer cell aggressiveness.

The study also suggested that very high blood levels of vitamin D may increase risk of death in women with breast cancer. This is a preliminary observation that requires further investigation.

The study looked at 512 Toronto women with early stage breast cancer more than 12 years after their initial diagnosis. Women under age 50, those who were overweight and those who consumed few grains and cereals had the lowest vitamin D levels. The vitamin D was measured in blood samples taken during both summer and winter months.

Dr. Goodwin recommends that breast cancer patients avoid high doses of vitamin D and suggests a moderate dosage, similar to that prescribed for bone health, until more information is available. Dr. Goodwin also recommends that patients consider having their blood levels of vitamin D checked to ensure they are in a healthy range.

“This work adds an important new link in the chain of evidence connecting proper amount of vitamin D with overall good health,” said Dr. Larry Norton, MD, Deputy Physician-in-Chief of Breast Cancer Programs at Memorial Sloan-Kettering Cancer Center and Chairman of the Executive Board of Scientific Advisors of The Breast Cancer Research Foundation.

This research was funded by The Breast Cancer Research Foundation ® (BCRF), New York. BCRF was founded in 1993 by Evelyn H. Lauder as an independent, not-for-profit 501(c)(3) organization dedicated to funding innovative clinical and translational research. The Foundation supports scientists at top universities and academic medical centers worldwide conducting the most advanced and promising breast cancer research that will lead to prevention and a cure in our lifetime. For more information, visit or call 1.866.FIND.A.CURE.

About the Samuel Lunenfeld Research Institute of Mount Sinai Hospital

The Samuel Lunenfeld Research Institute of Mount Sinai Hospital, a University of Toronto affiliated research centre established in 1985, is one of the world’s leading centres in biomedical research. 32 principal investigators lead research in diabetes, cancer biology, epidemiology, stem cell research, women’s and infants’ health, neurobiology and systems biology. For more information on the Samuel Lunenfeld Research Institute, please visit

To arrange an interview with Dr. Goodwin, please contact:

Nikki Luscombe
Communications Specialist
Samuel Lunenfeld Research Institute Of Mount Sinai Hospital
416 586-4800 x 2046

Jodi Salem
Media and Communications Specialist
Mount Sinai Hospital
416 586-4800 x 8306