Q: Should I take vitamin D and fish oil to lower my risk of heart disease and cancer?
A: 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 published in the New England Journal of Medicine is suggesting otherwise.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
We have a very good, very big study funded by the National Institutes of Health that says neither vitamin D nor fish oil reduce the risk of cancer or heart disease.
Researchers studied 25,871 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 did not 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 in 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. Therefore, our advice to people would be not to routinely take either unless there’s a very good other reason to take these supplements.
— Cardiologist Steven Nissen, MD, Chairman of the Department of Cardiovascular Medicine at Cleveland Clinic