Can Vitamin D, fish oil supplements reduce risk of cancer, heart disease: A new study in progress

A new government-sponsored study is underway to study vitamin D and fish oil to see whether either nutrient can lower a healthy person’s risk of getting cancer, heart disease or having a stroke.

The study targets a specific racial group – African Americans who tend to have higher risk of heart disease. It is believed that people with dark skin are unable to make much vitamin D from sunlight and this may help explain why blacks have higher rates of cancer, stroke and heart disease.

“If something as simple as taking a vitamin D pill could help lower these risks and eliminate these health disparities, that would be extraordinarily exciting,” said Dr. JoAnn Manson. She and Dr. Julie Buring, of Harvard-affiliated Brigham and Women’s Hospital in Boston, will co-lead the study.

“But we should be cautious before jumping on the bandwagon to take mega-doses of these supplements,” Manson warned. “We know from history that many of these nutrients that looked promising in observational studies didn’t pan out.”

However, it is a known fact that cancer rates are higher in many northern regions where sunlight is weak in the winter, and some studies have found that people with lower blood levels of vitamin D are more likely to develop cancer.

“Vitamin D and omega-3s have powerful anti-inflammatory effects that may be key factors in preventing many diseases. They may also work through other pathways that influence cancer and cardiovascular risk,” Manson said.

The new study, which will start later this year, will enroll l20,000 people with no history of heart attacks, stroke or a major cancer — women 65 or older and men 60 or older. They will be randomly assigned to take vitamin D, fish oil, both nutrients or dummy pills for five years.

The daily dose of vitamin D will be about 2,000 IU of D-3 and 1 gm of fish oil. Participants’ health will be monitored through questionnaires, medical records and in some cases, periodic in-person exams.

“We’re hoping to see a result during the trial, that we won’t have to wait five years” to find out if supplements help, Manson said. Researchers also plan to study whether these nutrients help prevent memory loss, depression, diabetes, osteoporosis and other problems, Buring said.

The $20 million study will be sponsored by the National Cancer Institute, with the National Heart, Lung and Blood Institute and other federal agencies. Pharmavite LLC of Northridge, Calif., is providing the vitamin D pills, and Ocean Nutrition Canada Ltd. Of Dartmouth, Nova Scotia, is providing the omega-3 fish oil capsules.

Details for the study is at: http://www.vitalstudy.org.