Breast cancer is the second most common cancer in the world and the most common among women. It is also among the ten most common chronic diseases of women, and a substantial contributor to loss of quality of life (Gronowski and Schindler, Table IV). Globally, it accounts for 25% of all cancers. In 2016, breast cancer is the most common cancer diagnosed among women in both developed and developing countries, accounting for nearly 30% of all cases, and worldwide accounts for one and a half million cases and over half a million deaths, being the fifth most common cause of cancer death overall and the second in developed regions. Geographic variation in incidence is the opposite of that of cervical cancer, being highest in Northern America and lowest in Eastern and Middle Africa, but mortality rates are relatively constant, resulting in a wide variance in case mortality, ranging from 25% in developed regions to 37% in developing regions, and with 62% of deaths occurring in developing countries.
Consult your health care professional. Women of childbearing age may want to consider taking folic acid supplements to reduce the risk of having a pregnancy affected with neural tube defects. Many women and teenage girls don't get enough calcium or vitamin D, both of which are critical to healthy bones and avoiding osteoporosis. Some people with diabetes appear to benefit from chromium. Vegetarians, especially vegans, may want to consider supplements to obtain nutrients they aren't getting from animal products.