The best way to get the vitamins, minerals, and nutrients necessary to fight prostate cancer is to follow a well-balanced prostate-healthy diet.  In other words, you should try to get the nutrition you need from what you eat and drink each day. But sometimes, men have specific deficiencies or circumstances that require them to add dietary supplements. For example, a Canadian man who works indoors may have a difficult time reaching optimal levels of vitamin D without taking a supplement, at least during fall and winter. (Vitamin D is synthesized in our bodies in response to sunlight, which is in short supply in Canada during the fall and winter months.)

However, using supplements to help prevent or control prostate cancer has remained controversial over the years, as we can see from some of the titles of PCCN articles on the subject:

Supplements for prostate health: So what does work? (April 2009)

Dietary supplements: The renewed debate (January 2008)

Vitamin supplements: Helpful or harmful? (May 2007)

Nevertheless, on this page, PCCN will present current information about which supplements might help prevent or delay prostate cancer and which should be avoided. Remember four important things, though, when you consult this information:

1. It may not be completely accurate or up to date because current knowledge about supplements is changing all the time; no information on the subject is definitive.
2. Whether to use dietary supplements for prostate health is a controversial topic because of the difficulties of assessing their health effects; some may help, and some may pose undiscovered health risks.
3. Always discuss with your doctor any vitamins, minerals, and herbal supplements you are using or plan to use. Although research suggests that some supplements may help prevent prostate cancer from developing or growing, we do know that others can be dangerous, and even so-called beneficial supplements can harm specific individuals—or many people if used incorrectly. Studies have even connected excessive use of multivitamins, zinc, iron, copper, and calcium with increased prostate cancer mortality.
4. When in doubt, leave a supplement out---try to fulfil your nutritional needs through diet and lifestyle changes.

Potentially Promising Supplements

Selenium and Vitamin E
Selenium is a crucial antioxidant, found in Brazil nuts, seafood, and grains, and it was initially thought to be a very promising tool in the reduction of prostate cancer risk. In trials, it was often paired with vitamin E because selenium seemed to make the antioxidant properties of vitamin E more effective. The recommended anti-cancer dose of selenium (200 μg) is difficult to achieve without a supplement. And natural sources of vitamin E (for example, nuts and oils) are high in fat. Consequently, both are often recommended as supplements. However, a large clinical trial (SELECT) that tested the effects on prostate cancer of selenium paired with 50 mg of vitamin E found neither beneficial. SELECT found that selenium and vitamin E when taken together over an average of 5.5 years did not prevent prostate cancer. It also turned up two concerns: there were slightly more prostate cancer cases among men taking only vitamin E and slightly more cases of diabetes among men taking only selenium.  (Learn more about the SELECT Prostate Cancer Prevention Trial.)

If you decide to take selenium and vitamin E, inform your physician, and do not exceed recommended doses. Vitamin E is often not advisable for men with heart conditions, Alzheimer’s, Parkinson’s, or diabetes mellitus. And selenium in higher doses than 200 μg each day can be dangerous.

Vitamin D
The possible role of vitamin D in treating or preventing prostate cancer is still being studied. Two things made researchers interested in this vitamin. First, they discovered that rates of prostate cancer are higher among men who live in northern countries or among those whose darker skin affects their production of vitamin D from sunlight exposure, e.g., Canadians of African descent. Second, prostate-specific antigen (PSA) rates appear to vary seasonally.  Levels of PSA, potentially a marker for prostate cancer, are lower in spring and summer, when vitamin D is produced at higher rates by the body in response to longer hours of sunshine.

Research has tended to support the vitamin’s benefits for prostate health. And there is evidence that it aids the effects of some forms of chemotherapy for metastatic prostate cancer. (See an abstract of this article.)  Still, overall, studies have not confirmed that vitamin D protects against the disease.

Nevertheless, because vitamin D is crucial for bone health, and Canadians often do not consume or produce enough of it, Health Canada, the Canadian Cancer Society, and the Prostate Cancer Research Institute recommend taking a supplement.

• Health Canada recommends that healthy adults under 70 years of age take 600 IU and that those over 70 take 800 IU.
• The Canadian Cancer Society recommends supplementing at 1,000 IU a day, at least during the fall and winter---and perhaps all year if you are older, have dark skin, don’t get outside much, or don’t get much sun when you are outside (because of sunscreen or other protection).
• The Prostate Cancer Research Institute (Los Angeles, CA) recommends 2,000 IU a day, and a minimum dose of 1,000 IU.

Note that Health Canada puts the “tolerable upper intake level per day” at 4,000 IU---and that’s from all sources, supplements as well as diet.

Lycopene
This antioxidant is easily consumed in the correct amount if you include tomato sauces and juices in your daily diet. At least 30 mg each day is the recommended amount; that’s about a cup of vegetable juice cocktail and a small wedge of watermelon. Some men decide to take about 15 to 30 mg daily as a supplement.

Pomegranate extract
Recent research suggests that pomegranate juice or pomegranate extract combats cancer, including prostate cancer. The thinking is that components in pomegranate juice and in the fruit’s skin both inhibit the movement of cancer cells and weaken their attraction to a chemical signal that promotes metastasis (or spread). The extract also seems to slow the rate of PSA rise in men whose levels are increasing. Still, research is inconclusive. Because the juice contains quite a bit of sugar, clinical trials often use a pomegranate pill.

Get These From Your Diet
Some research suggests that men with prostate cancer should not use supplements of calcium or zinc but should definitely get the recommended daily allowance of these from their diet.

• Calcium is absolutely necessary for bone health, so it is particularly important for men on long-term hormone therapy, who are at a higher risk for bone loss.  But some research suggests a link between excessive calcium intake and prostate cancer. Men with prostate cancer should get the recommended daily amount (1000 to 12000 mg) through diet.
• Zinc supplements are not recommended for men with prostate cancer. Get the very small amount you need by eating poultry, seafood (oysters and crab meat), and eggs.
• Vitamin A or beta-carotene is best consumed in your diet; some studies have found an association with using high-dose beta-carotene supplements and cancer. Just eat carrots and other orange, yellow, red, and dark-green fruits and vegetables.

It’s better (and easy) to get other potentially useful nutrients from what you eat and drink as well, rather than from supplements:

• Vitamin C, an antioxidant, is readily available in oranges, strawberries, broccoli, and red peppers.
• Grape seed extract is an untested supplement; get the polyphenols (perhaps its beneficial ingredient) from eating grapes.

Skip These
Some supplements remain untested or potentially harmful. Until more research comes out, men with prostate cancer should probably give these a miss.

• Prostate cancer-SPES (PC-SPES) was once a popular supplement among prostate cancer patients, but it was withdrawn in 2002 from the North American market. Credible evidence shows that this supplement can be dangerous, and its usefulness is not known.
• Shark cartilage seems to have no effect on prostate cancer, although it was thought at one time to retard blood vessel development and perhaps “starve” tumours. Avoid this.
• Saw palmetto and prostate health has been studied extensively, at this point. It may have a role in helping reduce the symptoms of prostatitis and benign-prostatic hyperplasia (BPH),  but long-term studies have found that its use does not affect prostate cancer risk.

Credible information on supplements is often difficult to come by, but check out some of the following websites:

Natural Health Products, Health Canada

CAMline: Evidenced-Base Complementary and Alternative Website for Healthcare Professionals, University of Toronto

Complementary and Alternative Cancer Therapies, BC Cancer Agency