There’s a good chance that you are among the masses of Americans who take vitamin D and fish-oil pills, having heard that they prevent cancer and heart disease. Indeed, it’s estimated that more than one in four U.S. citizens age 60-plus take vitamin D supplements, and more than one in five takes ones with omega-3 fatty acids (a key fish-oil ingredient).

The research involved a major federally funded look at over 26,000 people and declared these pills don’t do what we hoped they did.

You may want to rethink your pill-taking practices because a huge study just found that these supplements neither lower cancer rates in healthy adults nor diminish the occurrence of heart attacks, strokes, and deaths caused by cardiovascular disease. The research involved a major federally funded look at over 26,000 people and declared these pills don’t do what we hoped they did.

“It’s disappointing, but there have always been such high expectations that vitamin D can do all these different things,” said Dr. Clifford J. Rosen of the Maine Medical Center Research Institute in Scarborough, who was a co-author of an editorial on the studies in The New England Journal of Medicine in the New York Times. But he dismissed the ability of the vitamin to prevent diseases as “magical thinking.” And in terms of the omega-3 acids, he said that they do not lower the incidence of cancer or major cardiovascular events.

However, you may not want to trash your vitamin stash just yet. There were some glimmers of hope in the study, showing that some sub-groups may benefit from fish oil and vitamin D. For instance, when the researchers looked only at heart attack rates versus cardiovascular events as a whole, they found a 28 percent reduction in heart attacks among those who take fish oil, a 40 percent reduction among people who don’t eat much fish but do take fish oil, and a whopping 77 percent decrease among African-Americans.

So should you or shouldn’t you take them? “Talk to your doctor, especially if you have low fish intake or are African-American,” was the advice that Dr. JoAnn E. Manson, an investigator at Brigham and Women’s Hospital who led the trial, offered.  Also, don’t ignore that vitamin D is important to calcium absorption for bone health, so you may want to continue taking it for that reason alone.