Prostate cancerPatient friendly summary

  • Sunlight has a direct effect on reducing most prostate cancer risk.
  • Vitamin D levels up to 27 years prior to prostate cancer diagnosis do not seem to affect risk of prostate cancer.
  • Vitamin D has been shown to block tumor growth and the spread of cancer and may reduce the risk of death from prostate cancer.  

Prostate cancer is cancer of the component of the male reproductive system that provides some of the semen.  

Prostate cancer is an important cause of disease and death. In the United States each year, the disease affects about 240,000 men and kills approximately 34,000.

Risk factors

A number of risk factors are associated with prostate cancer. The most important include:

  • Diet high in animal products: Eating a lot of meat, eggs and dairy products, especially early in life, causes the body to produce a growth factor. Growth factors help the body grow. They also help tumors grow. Dairy products contain calcium and cholesterol. These products may also increase the risk of prostate cancer.
  • Calcium: High amounts of calcium, either from diet or supplements, may be a risk factor.
  • Cholesterol: High cholesterol levels are linked to an increased risk of prostate cancer. Cholesterol does not appear to affect risk of other cancers.
  • Genetics: Part of a gene sequence increases body cholesterol. This same sequence may increase the risk of prostate cancer. Genetics may explain why African-Americans have twice the rate of prostate cancer as European-Americans.

Sunlight exposure and prostate cancer risk

According to several studies, sunlight has a direct effect on lowering prostate cancer risks. This is especially true for people who had early-to-midlife sun exposure. The ultraviolet-B (UVB) portion of sunlight stimulates the body to produce vitamin D.

Studies also found that men who develop basal or squamous cell carcinoma (non-melanoma skin cancer) have a lower risk of prostate cancer if they live where it is warm enough to expose more than just face and hands.

Norwegian studies found increased survival rates for men diagnosed in summer, when there is more sunlight, compared to those diagnosed in winter.

Vitamin D and prostate cancer risk

Observational studies looking at vitamin D blood levels up to 27 years before diagnosis of prostate cancer generally did not find that vitamin D lowered the risk of this disease. Vitamin D may have little effect on prostate cancer as it progresses from the earliest growth stages until the disease is detected.

However, a recent study from Harvard involving health care professionals found that those with lower vitamin D levels were more likely to die of prostate cancer than those with higher vitamin D levels.

How vitamin D works

Calcitriol, the active form of vitamin D, is produced by the body. Calcitriol provides numerous benefits against cancers. This form of vitamin D encourages cells to either adapt to their organ or commit apoptosis (cell suicide). Calcitriol also limits blood supply to the tumor and reduces the spread of cancer. These may be the roles that vitamin D plays in prostate cancer, near the beginning and end stages.


Exposure to sunlight in early years to midlife may reduce the risk of prostate cancer.

Vitamin D may prevent prostate cancer at the earliest stages as well as reduce the risk of death from prostate cancer.


It appears as if vitamin D supplements could be used to treat those with prostate cancer; however, no studies have reported beneficial effects yet.

Find out more...

Do you want to find out more and see the research upon which this summary is based?  Read our detailed evidence summary on Prostate cancer.

Page last edited: 05 August 2011