Prostate cancer is a major public health problem in the United States. Thirty thousand of the 240,000 men diagnosed with the disease in the U.S. each year die.
A new study finds vitamin D deficiency is linked to an increased risk of the disease, especially the aggressive form of prostate cancer, which lead author Haojie Li of Brigham Women's Hospital (and an instructor at Harvard Medical School) says "usually has a fatal outcome.".
Li and her colleagues studied blood samples for protein biomarkers for vitamin D. The research team also searched for various forms of a gene that has been identified with vitamin D absorption. "People with a certain genetic makeup, when they have low vitamin D status, they are especially susceptible to the disease."
The scientists followed 15,000 men over 18 years. Despite the large number of participants, Li says most were Caucasian. So, she says, the findings cannot be applied to African-Americans or darker skinned ethnic groups who are known to produce less vitamin D in their skin when exposed to sunlight. "Potentially for African-Americans, vitamin D deficiency might be even a more severe issue to look at."
The sun is a major source of vitamin D, but too much sun exposure can cause skin cancer. Li says patients must strike the right balance to protect themselves. "Usually we say if people have a balanced diet plus moderate sun exposure in the summer they are doing fine."
Fish and vitamin D fortified dairy products are rich sources of vitamin D. The study is published in the PloS Medicine.