The Role of Vitamin D in Stopping Breast Cancer
Breast cancer is the most commonly diagnosed cancer in women in the United States after skin cancer. Some studies show that avoiding vitamin D deficiency may help to limit your risk of breast cancer. About 250,000 new cases of breast cancer were diagnosed in 2009, and about 40,000 deaths resulted from breast cancer.
Breast cancer risk factors and symptoms
Breast cancer usually arises in the ducts of the breast that carry the milk to the nipple. Less often, it begins in the lobules of the breast where milk is formed.
A number of risk factors can contribute to breast cancer, beyond gender:
Lack of exercise
Increased consumption of alcohol
Estrogen supplementation in postmenopausal women
Age (it occurs more in older women)
Personal or family history of breast cancer
Absence of pregnancies and lack of breastfeeding
Abnormalities of two major breast cancer susceptibility genes, BRCA 1 and 2 (these abnormalities run in families)
Like most cancers, breast cancer in its early stages does not have any symptoms. As the cancer enlarges, the following symptoms and signs occur:
A painless lump in the breast or armpit that is hard and uneven
Redness, dimpling, or puckering of the skin of the breast
Discharge from the nipple that can be bloody
Breast cancer diagnosis and treatment
The diagnosis of breast cancer is usually made with a fine needle biopsy of the suspicious lump. Then the cancer is staged. This means classifying the cancer as follows:
Stage 0 is premalignant. Cancer cells are present in the duct but don’t invade surrounding tissue.
Stage 1 cancer has cancerous cells invading nearby normal tissue.
Stage 2 cancer has invaded lymph nodes or is no larger than 5 centimeters.
Stage 3 cancer has spread beyond the lymph nodes under the arm.
Stage 4 has spread to other organs, most often lungs, liver, bone, or brain. Only stage 4 is considered incurable.
Treatment usually starts with surgery and depends on the size and spread of the cancer (that is, the stage of the cancer). After surgery, the patient generally undergoes radiation therapy and/or chemotherapy to kill any cancer cells that may have been left after removing the lump. Some cancers grow in response to estrogen; when that’s the case, agents that block estrogen action are given.
The prognosis for breast cancer recovery isn’t as good for younger women because the cancers they develop tend to be more aggressive. As a group, black women are more likely to die from breast cancer than white women. This is linked to lower incomes and reduced likelihood of insurance coverage, which reduces breast cancer screening and causes less intensive care after diagnosis.
Vitamin D’s role in breast cancer
A number of studies exist from cells and animals that show calcitriol affects the cells of the breast and limits the growth of cancer cells. There are also some interesting associations between vitamin D intake or serum 25-hydroxyvitamin D and breast health. Consider some of the more important findings:
Calcitriol decreases the proliferation of abnormal breast cells in cell cultures and blocks the actions of estrogen that tend to produce cancer cells.
Mice without the vitamin D receptor gene have abnormal development of the breast and develop more severe breast cancer.
Drugs developed to function like calcitriol can reduce the development of breast cancer in animal models by slowing the growth of tumor cells and by blocking their ability to spread.
Breast cancer occurs less frequently in areas with more sunlight.
Women with very low vitamin D intake (less than 200 IU per day) are more likely to have mammograms that indicate increased breast cancer risk.
Several studies suggest that women with high blood 25(OH) vitamin D levels are less likely to develop breast cancer.
High vitamin D intake reduces the pain associated with treatment of breast cancer by a class of drugs called aromatase inhibitors.
Although proof is lacking that suggests taking higher amounts of vitamin D will prevent breast cancer, these studies point to a clear benefit of avoiding vitamin D deficiency if you want to limit your risk of breast cancer. For women, this makes two good reasons to get enough vitamin D — better bones, and less risk of breast cancer.
A sensible plan is to help prevent the occurrence of breast cancer by maintaining healthy levels of 25(OH) vitamin D throughout life.