Summer is the best time to benefit from vitamin D and its anti-cancer effects, because our body manufactures it as soon as it’s exposed to the sun.

Recently I received an email from a reader talking about his prostate cancer, and I wanted to tell him about the importance of vitamin D. I’m on vacation currently with my son Sacha, and I’m often out in the sunlight. Every time I lie on the sandy beach I think about the 10,000 units of vitamin D that our body manufactures in just twenty minutes of exposure to the sun.

A study by a cancer center in Toronto, Canada, analyzed 15 patients who had all been operated for prostate cancer, and whose disease was beginning to take over (Reference 1). Their prostate-specific antigen (PSA) level was rising regularly. All these patients were given a daily dose of 2,000 international units (50 micrograms) of vitamin D3 (cholecalciferol) – no more than that -- by oral ingestion. Their blood level of PSA was then analyzed every two to three months. In 14 of these 15 patients, the doubling time of PSA increased, demonstrating that the progression of their illness was slowing. For 9 of the 15, the PSA level did not increase at all, and even began to diminish, after the onset of their vitamin D-3 treatment. It was as if the progress of the disease had been stopped.

In the summer months, all you need to do to manufacture enough vitamin D3 is get out in the sunlight every day– and it’s completely free! Do be careful to avoid sunburn, though. Sunburns are not useful in terms of manufacturing the vitamin D3 that acts against cancer cells – and they may contribute to skin cancers.

You’ll find more information on vitamin D3 and its role in preventing and treating cancer in my book, Anticancer: A New Way of Life. Even if this research is just a pilot study (15 patients isn’t a whole lot), given that vitamin D3 at these low doses generally has no bad side-effects, it would be a pity not to apply the information.

1. Woo TCS, Choo R, Jamieson M, Chander S, Vieth R. Pilot study: potential role of vitamin D (Cholecalciferol) in patients with PSA relapse after definitive therapy. Nutr Cancer 2005;51(1):32-6.