(WJBK) - Millions of Americans take fish oil and vitamin D because of claims that these supplements may reduce the risk of heart disease and cancer. But, new research is suggesting otherwise.
Cleveland Clinic's Dr. Steve Nissen did not conduct the study, but says the results show no benefit.
"We have a very good, very big study that says neither vitamin D nor fish oil reduce the risk of cancer or heart disease," he says.
Researchers studied more than 25,000 men and women age 50 and older for about five years. Study participants were split into four groups: one group took 2,000 international units of vitamin D plus one gram of fish oil daily. Another group took vitamin D only; while another took fish oil only. The final quarter of participants didn't take anything.
The primary goal of the study was to see if the supplements impacted the risk of developing cancer or heart disease.
Overall, results show vitamin D and fish oil were not effective preventing cancer or heart disease.
"The good news is that both the fish oil and the vitamin D were safe; there was no harm - but there was also no benefit. And so, our advice to people would be not to routinely take either unless there's a very good other reason to take these supplements," Dr. Nissen says.
Vitamin D testing has turned into big business for labs and a big expense for taxpayers. Doctors ordered more than 10 million vitamin D tests for Medicare patients at a cost of $365 million.
Complete results can be found in the New England Journal of Medicine.