Vitamin D Newsletter


Summer Diagnosis Means Better Prognosis

Katie from Baltimore writes:

Dr. Cannell: I have cancer of the colon and the doctors couldn't get it all. I've read about studies showing that cancer patients diagnosed in the summer have a better chance of living. Does this mean vitamin D might help my cancer? How much should I take?

Dr. Cannell replies:

That is exactly what these studies mean—vitamin D might help treat cancer. They strongly imply a treatment effect. We won't know for sure until a direct study is done, that is, we need to give relatively high doses of vitamin D to cancer patients to see if they live longer compared to patients given sugar pills. Given what is known, I sure wouldn't want to be one of the cancer patients assigned to take the sugar pills.

Professor Johan Moan, from the Department of Physics at the University of Oslo, was the senior author that first reported an association between summer diagnosis and better prognosis. His group then verified it with colon cancer and breast cancer and extended it to Hodgkin lymphoma. They will soon publish a paper showing it is true for lung cancer as well. 

A group from Harvard led by Dr. Wei Zhou and Professor David Christiani took it one step further, combining season of diagnosis with vitamin D intake. They concluded that those lung cancer patients diagnosed during the sunny months who also had the highest vitamin D intake "had a 3-fold better recurrence free survival and a 4‑fold better overall survival than those with surgery in winter and low vitamin D intake." These results were truly amazing and suggest the long sought "cure" for cancer will not be coming out of the pharmaceutical industry but from health food stores and sun tan booths. Anything that prolongs survival is, by definition, effective treatment.  Zhou W, Suk R, Liu G, Park S, Neuberg DS, Wain JC, Lynch TJ, Giovannucci E, Christiani DC. Vitamin D is associated with improved survival in early-stage non-small cell lung cancer patients. Cancer Epidemiol Biomarkers Prev. 2005 Oct;14(10):2303–9.

At this point, no one knows if oral vitamin D would slow down your cancer or how much you should take. I take 5,000 IU in the colder months and go into the sun in the warmer months, just to maintain my 25(OH)D around 50 ng/mL. Future research may show that 10,000 IU per day is indicated in cancer treatment, we just don't know. Anyone taking that amount should have be under the care of a knowledgeable physician and have their 25(OH)D and serum calcium checked on a regular basis. At this point, the question is not if cancer patients should take vitamin D. The question is: should cancer patients die vitamin D deficient? (PDF format.)

Page last edited: 07 November 2010