LOS ANGELES, Dec. 21 (UPI) -- Taking supplemental vitamins and minerals won't prevent cancer, strokes or heart disease results of long-term trials suggest.
The trials counter a widespread belief held since the 1990s that taking vitamins and minerals could play a key role in preventing ailments, especially in older people, the Los Angeles Times reported Sunday.
In some cases, taking supplements can be unsafe, said doctors, noting a healthy diet provides all that most people need.
"These things are ineffective, and in high doses they can cause harm," said Dr. Edgar R. Miller of Johns Hopkins University School of Medicine in Baltimore. "People are unhappy with their diets, they're stressed out and they think it will help. It's just wishful thinking."
An estimated 64 percent of U.S. adults take supplemental vitamins and minerals, with sales rising from $5 billion in 1995 to $10 billion this year, the Times reported. The newspaper noted it reviewed five studies sponsored by the National Institutes of Health that tracked tens of thousands of people for various ailments, including pancreatic, breast and prostate cancers.