Calcium Curbs Breast Cancers Spread to Skeleton
Women battling breast cancer should make sure they get plenty of calcium and vitamin D. A new study suggests that a strong skeleton is less likely to be invaded by metastasizing cancer cells. Calcium and vitamin D help maintain strong bones.
The study looked at the role of bone turnover in the spread of cancer. According to the researchers, about 70 percent of people who have advanced breast cancer will develop secondary tumors in their bones. The tumors start a process of bone breakdown and subsequent bone growth, a vicious cycle that makes bones conducive to cancer growth.
Researchers compared the effects of a low- and high-calcium diet in subjects. They found that a deficiency of calcium was related to a significantly higher increase in cancer cell proliferation and the total proportion of bone that had been penetrated by cancer cells. (Zheng, Y., et al. Cancer Research, 2007 Oct 1;67(19):9542-8.)
They note that breast cancer patients frequently have low dietary calcium intake and high bone turnover, and suggest that treatment of calcium insufficiency and/or drug treatments to stop bone resorption (the process by which old bone is broken down and removed) may help to stop cancer spread to bones.
Aim for about 1,200 mg a day of calcium. (Most people need to take supplements to reach that amount. Average intake from foods is less than 800 mg a day.) Vitamin D is important because it aids calcium absorption and has its own anti-cancer effects. Experts are now calling for upwards of 1,000 IU a day of vitamin D3. The ability to absorb calcium decreases after menopause, so it’s important to keep tabs on these two nutrients. Your doctor can help you monitor blood levels. This is especially important if you have cancer.
