From the L.A. Times and Mount Sinai Hospital comes a report that breast cancer patients who had below-normal levels of vitamin D when diagnosed were a staggering 94% more likely to have their cancer metastasize, and 73% more likely to die within 10 years of diagnosis.
These results are preliminary and it is far too early for doctors to begin advising women to take vitamin D to help combat cancer. That said, striving for 100% of the daily recommended amount would be wise anyway. Vitamin D has a number of beneficial effects on the body, although taking too much can also cause problems. The best form of vitamin D, D3, is produced naturally in the body due to exposure to sunlight, and is considered the most useful form.
So spending more time in the sunlight may have beneficial effects for helping fight breast cancer or preventing its spread. But be careful not to get skin cancer from over-exposure!