According to results reported in the journal Cancer Research, a combination of the vitamin D analog Calcitriol, and over-the-counter painkillers (NSAIDs,) has been shown to greatly reduce the growth of prostate cancer cells in the lab. A team of researchers at Stanford University’s School of Medicine found that while Calcitriol alone reduced prostate cancer cell growth by 25 percent, and the use of only ibuprofen or naproxen caused a similar reduction, the combination of Calcitriol and one of the painkillers reduced growth by an impressive 70 percent. They were impressed enough with the results to start a clinical trial. From Reuters:

Feldman stressed that his team is testing calcitriol, a form of vitamin D that is efficiently used by the body and different from the sort found in vitamin pills and fortified milk.

“We don’t want the patient to think that if they take over-the-counter vitamin D, it will work in the same way,” Feldman said.

…Feldman’s team plans to test the drugs in men whose prostate cancer has returned after surgery or radiation therapy.

One important caveat: Vitamin D is one of the few vitamins that can be highly toxic at fairly low doses, so self-treatment with over the counter vitamin D is dangerous. That said, I am personally a big proponent of getting your vitamin D the way nature intended, through adequate exposure to sunlight. As always, you should seek the advice of your physician or other qualified health professional before starting any new treatment or making any changes to existing treatment.

You can read the abstract at: Regulation of Prostaglandin Metabolism by Calcitriol Attenuates Growth Stimulation in Prostate Cancer Cells