Researchers have long known that vitamin D interferes with the ability of cancer cell to divide. There is also a known link between breast cancer and lack of exposure to sunlight, which can lead to Vitamin D deficiency. Now, a new study suggests that taking Vitamin D may actually help curb breast cancer progression.
The admittedly small study looked at 279 women with invasive breast cancer. Levels of vitamin D, parathyroid hormone and calcium were measured.
The results showed that women in the early stages of the disease had significantly higher levels of vitamin D and significantly lower levels of parathyroid hormone than did the women with advanced disease.
There was little difference in calcium levels between the two groups.
Writing in the October, 2006 Journal of Clinical Pathology, the authors say that the exact reasons for the difference are unclear, and it is not known whether the low levels of vitamin D among those with advanced disease are a cause or an effect of the cancer.
But it is known that vitamin D treatment boosts the activity of certain key genes and dampens it down in others. One gene that is boosted is p21, which has an important role in controlling the cell cycle.
Therefore, they say, it is reasonable to suspect that low levels of vitamin D in the body may promote progression to advanced disease.