Calcium D-glucarate is a chemical similar to glucaric acid. Glucaric acid is naturally found in the body and in some fruits and vegetables.
Calcium D-glucarate is made by combining glucaric acid with calcium. Calcium D-glucarate might lower estrogen levels, which might have effects in some people with hormone-dependent cancers.
People use calcium D-glucarate for preventing breast cancer, prostate cancer, and colon cancer, and for treating other conditions, but there is no good scientific evidence to support these uses.
Don't confuse calcium D-glucarate with calcium. These are not the same.