The study found that vitamin D promotes mammary cell development and inhibits the reproduction of malignant (cancerous) cells. Researchers looked at a cohort of 1,666 women with invasive breast cancer to determine whether levels of a vitamin D biomarker called 25-hydroxyvitamin D (250HD) were linked to survival prognosis. They found that elevated blood levels of 250HD were associated with better overall survival, and in premenopausal women, the association between higher levels of 250HD and survival was even stronger.

“Overall, we found a 30 percent reduction of all-cause mortality associated with vitamin D levels at the time of diagnosis,” said Song Yao, of the Roswell Park Cancer Institute in Buffalo, New York, and lead author of the study.

As part of the follow-up, patients were checked for comorbidities and overall health at 12, 24, 48, 72 and 96 months. Researchers found lower levels of 250HD in women with advanced-stage tumors.

The lowest levels were found in premenopausal women with triple-negative cancer, a form of the disease that tends to have worse outcomes than other types of breast cancer. Levels of 25OHD were also inversely proportional to cancer progression and death rates.

Over an average of seven years of follow-up, about 100 breast cancer patients with the lowest vitamin D levels died, compared to 76 women with the highest levels of vitamin D.

“Our findings provide compelling observational evidence for inverse associations between vitamin D levels and risk of breast cancer progression and death,” the researchers concluded.

Vitamin D, also known as the sunshine vitamin, is important for regulating the absorption of calcium and facilitating healthy immune system function. Getting a sufficient amount of vitamin D is essential for normal growth of bones and teeth, as well as improved resistance against cancer, type 1 diabetes, heart disease and osteoporosis.

For most people, the best way to get enough vitamin D is by taking a supplement; however, the level in most multivitamins — 400 international units (IU) — is too low. Some manufacturers have begun adding 800-1,000 IU of vitamin D to their standard multivitamin preparations. If the multivitamin you take does not have 1,000 IU of vitamin D, you may want to consider a separate vitamin D supplement, especially if you don’t spend much time in the sun.

Source: JAMA Oncology

Posted by Ray Simon

Ray Simon is a veteran copywriter with more than a decade's worth of experience in the field. He studied journalism at Vanderbilt University, graduating Cum Laude in 2007. Ray currently specializes in writing content and news articles for independent publications.