A research study coming out of Canada indicates that Vitamin D may play a pivotal role in the progressive nature of breast cancer. The research subjects were diagnosed with breast cancer between 1989 and 1995, and followed until 2006. The study showed that women who were vitamin D deficient at the time of their diagnosis were 94% more likely to have the cancer spread, and 73% more likely to die from the cancer, compared with women who were not vitamin D deficient. Researchers also reported that 75% of the subjects suffered a vitamin D deficiency at the time of their diagnosis.
The researchers found that more than 37% of the women had deficient levels — below widely accepted standards — and 38% had slightly higher, “insufficient” levels. Less than one in four had sufficient amounts of the vitamin. Those with deficient levels were twice as likely to see the cancer recur outside their breasts over a 10-year period, and 75% were more likely to die as those with sufficient levels, the scientists found.
The chief source for vitamin D is sun exposure, since the ultraviolet rays of the sun trigger vitamin D synthesis within the human body. This has led to a debate on the value of taking supplements. The study also suggests that very high levels of the nutrient may actually increase the risk of death in women with breast cancer.
“Our results need to be replicated in other clinical studies,” cautioned on of the scientists. “These data indicate an association between vitamin D and breast cancer outcome, but we can’t say at this time if it is causal.” This caution was echoed by Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, “I agree with researchers for putting study in proper light — that it’s a preliminary study and needs to be confirmed by more research, and doctors should not make specific recommendations to women with breast cancer based on this study.”