In a new study presented at the ASCO conference, where 40,000 oncologists, researchers, scientists, drug company officials and journalists convened to discuss the latest innovations in cancer research, vitamin D proved to have beneficial effects on survival for people with cancer, though they it doesn’t appear to impact the risk of getting cancer.
“What they found is that if someone took at least three years of Vitamin D supplementation versus a placebo drug, they were less likely to die from a a death related to cancer,” says Dr. Heather Yeo, Colorectal Surgeon and Surgical Oncologist at Weill Cornell Medicine and NewYork-Presbyterian. “If you took placebo versus vitamin D for that period of time, there was no difference in whether you actually got cancer.”
Read MoreIn this case, one criterion was that studies included had to have patients who took vitamin D over a period of three years while being monitored, and patients who took a placebo drug over that same period of time.
Another criterion was that studies included for meta-analysis had to be randomized, controlled trial– People in the study had to be randomized for taking vitamin D or the placebo drug.
The studies included could have been initially designed to for any purpose– they might have studied hypertension, heart failure, anything– but they had to report on cancer incidences and cancer-related death.
The average age of patients in the study was 68.07, which, according to Dr. Yeo, “makes sense because over a number of cancers, the highest incidence is in the sixty-to-seventy age range.”
And 78.02 percent of people in the study were women. “The majority of patients were women, which probably means some of there studies were focused on diseases women have,” continues Dr. Yeo.
Aside from just contributing to health bones, the study suggests that the vitamin can actually help cancer patients live longer.
In terms of the exact mechanism is that makes vitamin D useful for people with cancer, there isn’t enough evidence to really understand what it is, according to Dr. Yeo.. “We don’t really know the pathophysiology behind it.”
The study did not observe any correlation between Vitamin D intake and cancer incidence. And even if it did show some correlation, it would be very hard to parse out the effect of vitamin D on cancer risk, versus other environmental factors. “The reality is that there have been a number of observational studies that have shown that low vitamin D seems to put you at risk of cancers,” says Dr. Yeo. “But we don’t know if the low vitamin D comes from where people live, their race, or other environmental factors, and those factors might be the contributing factors to cancer.”
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