Researchers at the College of Physicians and Surgeons,
Columbia University, at Mt. Sinai School of Medicine, and the
University of North Carolina note that having a sufficient level of
Vitamin lowers the risk of developing several cancers.
In experimental studies, vitamin D has been shown to inhibit
the proliferation of cells (rapid multiplication) and induce
differentiation (restore normalcy) and apoptosis (cause them to die) in
normal and malignant breast cells. Using a population-based
case-control study on Long Island, New York, they examined the
association of breast cancer with plasma 25-hydroxyvitamin D (25-OHD)
levels, a measure of vitamin D body stores in the body.
Interviews and blood specimens were obtained from 1,026 women
with breast cancer diagnosed in 1996 to 1997 and 1,075 cancer free
women who were used for comparisons sake (these are called controls).
Plasma 25-OHD was measured in batched, archived specimens by Diasorin
RIA. The mean plasma 25-OHD concentration was higher in cancer free
women than in those with breast cancer. Plasma 25-OHD was inversely
associated with breast cancer risk in a concentration-dependent
fashion. Compared with women with vitamin D deficiency of less than 20
ng/mL, levels above 40 ng/mL were associated with a 44% decreased risk
of developing breast cancer. The reduction in risk was greater among
postmenopausal women with a 54% decreased risk, and the effect did not
vary according to tumor hormone receptor status.
In summary, these results add to a growing body of evidence that
adequate Vitamin D stores may prevent breast cancer development.
Whereas circulating 25-OHD levels of greater than 32 ng/mL are
associated with normal bone mineral metabolism, our data suggest that
the optimal level for breast cancer prevention is greater than or equal
to 40 ng/mL. The study is published in the June 1, 2009 issue of the
journal Cancer Prevention Research.
