Can vitamin D and fish oil omega-3 supplements reduce the risks of cancer, heart disease, and stroke? That’s one of the questions researchers are hoping to answer in the the VITamin D and OmegA-3 TriaL (VITAL). VITAL is a randomized clinical trial studying the effect of vitamin D at a dose of 2,000 international units (IUs) per day and omega-3 fatty acids at a dose of one gram per day in the prevention of cancer, heart disease, and stroke in people without a prior history of these illnesses.
The Institute of Medicine currently recommends 600 IUs per day of vitamin D for adults up to age 70 and 800 IUs a day after age 70 to protect the bones and reduce the risk of fractures, osteoporosis, osteomalacia, and other bone health problems. However, it’s not known whether giving higher amounts would be of benefit in preventing heart attack, stroke, and cancer. Also of interest will be the effects of the supplements on risks of diabetes, cognitive decline, autoimmune disorders, and other outcomes. Half of the 26,000 VITAL participants are receiving 2000 IUs of Vitamin D per day, and their health outcomes are being compared to participants receiving a placebo.
VITAL also will be the first large-scale, randomized clinical trial to study the role of omega-3s in the prevention of first cardiovascular events and cancer in a generally healthy population. Half of the VITAL participants also are receiving one gram of omega-3s, and their health outcomes are being compared to those receiving a placebo. The American Heart Association currently recommends one gram per day of omega-3s for people who already have a history of heart disease. However, in general, the U.S. population gets only about one-fourth to one-fifth that amount of omega-3s in their diet.
JoAnn E. Manson, MD, DrPH, Principal Investigator, VITAL Main Study, and Chief, Division of Preventive Medicine at Brigham and Women’s Hospital, describes the primary and secondary goals of VITAL and how the study results may impact future public health recommendations.