The vitamin D levels in women when they are diagnosed with breast cancer may affect how long they will live, according to a new study from Belguim.

Women in the study who had the highest vitamin D levels (above 30 nanograms per millileter of blood) were about half as likely to die within five years of their diagnosis as women with lower vitamin D levels (below 30 ng/ml). And every 10 ng/ml increase in vitamin D levels at diagnosis was linked with a 20 percent reduction in women's risk of dying over the course of the study.

The link held even when researchers took into account factors known to influence women's cancer survival rates, such as body mass index and age.

Additionally, women in the study with higher vitamin D levels were more likely to have smaller tumors when they were diagnosed.

Researchers stressed that the study shows an association between the vitamin and survival rates, not a cause-and-effect link, and more work would be needed to confirm the findings. Researchers did not attempt to change women's vitamin D levels during the study they took one measurement of vitamin D levels at the time of diagnosis.

The findings mean that physicians and oncologists are going to have to pay attention to vitamin D levels "more closely as their patients go through treatment,â€� said Luke Peppone, a clinical cancerresearcher at the University of Rochester in New York, who was not involved in the study.

Peppone noted that previous research suggested vitamin D may reduce cancer risks but that the evidence isn't Monday, June 11, 2012