An article published online on October 9, 2013 in Breast Cancer Research and Treatment reports the results of a meta-analysis conducted by Canadian researchers which found an association between higher serum levels of vitamin D and better prognosis for women with early stage breast cancer.
For their analysis, Pamela J. Goodwin of the University of Toronto and her colleagues selected eight studies involving a total of 5,691 women diagnosed with breast cancer from 1973 to 2010. Blood samples were collected, on average, within 90 days of diagnosis or shortly before treatment. Deficient levels of vitamin D were uncovered in 38.6% of the subjects.
When the lowest versus highest categories of serum vitamin D were compared in a pooled analysis, women whose levels were low had a risk of recurrence that was more than double that of subjects whose levels were high and a risk of death that was 76% higher.
The authors remark that vitamin D, when activated, can alter the transcription and expression of specific genes, resulting in growth arrest, apoptosis, aromatase suppression, decreased inflammation, and inhibition of angiogenesis, invasion and metastasis, all of which help combat cancer.
“These findings support an association of low levels of vitamin D with increased risk of recurrence and death in early stage breast cancer patients,” the authors conclude.