“Doctors should emphasize the importance of maintaining adequate serum vitamin D levels, which would be 40 to 60 ng/mL for cancer prevention, and encourage their patients to have their vitamin D status regularly checked, especially in winter, to ensure that adequate serum levels are being maintained,” said first author Sharif B. Mohr, MD, from the Naval Health Research Center in San Diego (6).
For women already diagnosed with breast cancer, vitamin D levels could go as high as 80 ng/mL, he told Medscape Medical News.
Low levels of vitamin D were not only found to increase risk of developing breast cancer but is also linked to more-aggressive tumors and worse outcomes (7).
“Although much more research needs to be done, research from our lab and others suggests that people at risk for breast cancer should know their vitamin D levels and take steps to correct any deficiencies,” said Brian Feldman, MD, PhD, assistant professor of pediatrics.
Prostate Cancer
A new study from the Northwestern University Feinberg School of Medicine suggests a link between low levels of the vitamin and aggressive prostate cancer. In fact, low serum vitamin D was found to be a clear markers of prostate cancer risk (8).
The vitamin also prevented the proliferation and differentiation of cancer cells.
The cross-sectional study of research from 2009-2014 was a part of a larger epidemiologic study of 1760 cancer screenings compared to healthy controls.
“If you place prostate cancer cells in a dish with vitamin D, growth rate slows, the cells become less invasive, and there is a greater likelihood the cells undergo apoptosis,” says Adam Murphy, MD, lead author and assistant professor of Urology, Northwestern University.