Low level of vitamin D increases the risk of breast cancer metastasis and death

May 19, 2008

Breast cancer patients with lower levels of vitamin D were far more likely to die and far more likely to have their cancer spread than women with normal levels, Canadian researchers reported on Thursday. In fact the women deficient in Vitamin D when they were diagnosed with breast cancer were 94 % more likely to have their cancer spread and were 73 % more likely to die than women with adequate vitamin D levels, and More than three-quarters of the women with breast cancer had a vitamin D deficiency the researchers said. “The women with the lowest vitamin D levels had the highest risk of death from breast cancer," Dr. Richard Schilsky, of the University of Chicago and president-elect of ASCO stated in an interview with Reuters.

     Goodwin said optimal levels of active vitamin D in the blood are considered to be somewhere between 80 and 110 or 120 nmol/L (nanomoles per liter) of blood, although there are no standard guidelines. They considered anything less than 50 nmol/L to be deficient; only 24% of the women with breast cancer had adequate levels. Women with low vitamin D levels were also likely to have developed cancer before reaching menopause, had higher body mass indexes -- a measure of being overweight -- had higher insulin levels and had more aggressive tumors. The researchers reported their results at a meeting of the American Society of Clinical Oncology.

Raising Vitamin D levels could cut down the number of people who develop colon or breast cancer by tens-of-thousands each year

In lab experiments Vitamin D helps prevent cancer cells from growing and spreading. In published clinical trials people who were supplemented with high dosages of Vitamin D had fewer cancers. In this new study scientists from the University of California, San Diego, compared the average-wintertime blood levels and the rates of both colon and breast cancer in 15 countries. The rates of the cancers fell as the blood levels of Vitamin D increased. The average late-winter Vitamin D level among Americans was 15-18 ng/ml. The protective effect against colon cancer appeared to begin when blood levels reached 22 ng/ml. For breast cancer the protective effect started when blood levels reached 32 ng/ml. Based on the data the researchers argue that if Americans were able to maintain a Vitamin D level of at least 55 ng/ml, there would be 60,000 fewer cases of colon cancer (number of new cases estimated each year in the USA is 107,300), and 85,000 fewer cases of breast cancer (out of an estimated 180,000 new cases each year). Therefore about 56% of all cases of colon cancer and 47% of all cases of breast cancer in the USA would be totally prevented simply by raising the blood level of this inexpensive and safe Vitamin (and that is just in one year). Worldwide the number of colon cancer cases would drop by 250,000 and the number of cases of breast cancer would drop by 350,000. The researchers estimate that besides modest sun exposure people should consume 2000 IU of Vitamin D every day. The study is published in the August 2007 issue of the journal Nutrition Reviews.