Sunlight is anti-cancer!

Dear Dr. Cannell:

My mother died of breast cancer and my sister has had it for two years. Now I have it. How much vitamin D should I take?

Dear Shannon:

As I’ve said before, if I had cancer, I’d take 5,000 IU of vitamin D every day in the colder months. In the warmer months, I’d stop the vitamin D and get a safe amount of noontime sunshine. I’d keep my 25-hydroxy-vitamin D levels between 50 and 70 ng/ml, year around. However, I do that now and I’ve not been diagnosed with cancer. Several recent studies are relevant to breast cancer. Dr. Carlo Palmieri, and his group from the Imperial College in London, found that women with early stage breast cancer had higher vitamin D blood levels than women with more advanced cancers.

<>Palmieri C, et al.<>

Serum 25 hydroxyvitamin D levels in early and advanced breast cancer. J Clin Pathol. 2006 Oct 17;

Even more important was the third study reported to date, this time by Dr. Lim at the King’s College in London, showing improved survival when cancer is diagnosed in sunnier months. Studies of season of diagnosis and cancer survival are very important because they imply a treatment effect from higher vitamin D blood levels.
<>Lim HS, et al. Cancer survival is dependent on season of diagnosis and sunlight exposure. Int J Cancer. 2006 Oct 1;119(7):1530-6.

In terms of sunlight and cancer incidence, a recent literature review found 94 studies. The authors threw out 67 of the papers for not meeting their strict criteria, although every one of the discarded papers looking at the big three (prostate, breast, and colon cancer) showed sunlight reduces cancer. Of the remaining 27 papers, 8 of 8 prostate cancer papers, 7 of 7 breast cancer papers, and 5 of 6 colon cancer papers showed sunlight prevented cancer. The authors concluded, “There is increasing and conclusive evidence that sunlight has a preventative effect on the initiation and/or progression of prostate and breast cancer, colon and possibly also ovarian cancer.” Someone needs to tell that to Professor Gilchrest.
<>van der Rhee HJ, et al. Does sunlight prevent cancer? A systematic review. Eur J Cancer. 2006 Sep;42(14):2222-32. Epub 2006 Aug 10.

All this leaves us with a question, “Are physicians responsible for their advice?” When dermatologists or other physicians subvert the vitamin D steroid hormone system by telling patients to avoid the sun, do they assume an affirmative duty to assess and maintain the vitamin D system they have subverted? Do they have a duty to inform their patients about relevant risks of sun-avoidance? Do they have a duty to inform their patients about relevant risks of vitamin D deficiency? How many dermatologists even bother to check vitamin D levels in their pale-as-ghost patients? How many bother to advise vitamin D supplements? If they do advise supplements, how many advise enough vitamin D to compensate for lack of sunlight? These are questions for tort lawyers.

John Cannell, MD

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