MONDAY, Oct. 10 (HealthDay News) -- Far from being healthy,
supplements such as multivitamins, minerals and folic acid may
actually raise the odds for death in older women who take them, a
new study suggests.
Dietary supplements are widely used in the United States, often
with the hope of avoiding chronic disease. However, the long-term
health consequences of many compounds are unknown, the researchers
"Our study raises concerns about the safety of a number of commonly used dietary supplements," said lead researcher Jaakko Mursu, a nutritional epidemiologist at the University of Eastern Finland, in Kuopio. "We would advise people to reconsider whether they need to use supplements and put more emphasis on a healthy diet," he said.
The report was published in the Oct. 10 issue of the
Archives of Internal Medicine.
For the study, Mursu's team collected data on nearly 39,000
women who took part in the Iowa Women's Health Study. Specifically,
the researchers looked for a connection between taking dietary
supplements and the risk of death. The women in the study had an
average age of 62 and reported their supplement use in 1986, 1997
Over 19 years of follow-up, 15,594 of the women died. Supplement
use increased from 1986, when 63 percent of the women reported
taking at least one supplement, to 85 percent in 2004, the
One supplement decreased the risk of dying, but most did not,
Mursu's group found.
Multivitamins, vitamin B6, folic acid, iron, magnesium, zinc and
copper were associated with increased risk of death, they said.
However, calcium supplements seemed to reduce risk of death, they
The strongest association between a supplement and an increased
risk of death was for iron, Mursu's team noted. The more iron one
took, the greater the risk, and as one aged, it took less iron to
increase the risk of dying, the researchers said.
"This, of course, is just one study, and other similar studies have not found such a dramatic increase in mortality," said Mursu, who is also affiliated with the University of Minnesota. "Nevertheless, these studies have provided very little evidence that commonly used dietary supplements would help to prevent chronic diseases."
It should be noted that the study found an association between
supplement use and health risks, but did not prove a
Speaking for the supplement industry, Duffy MacKay, vice
president for scientific and regulatory affairs at the Council for
Responsible Nutrition, said that people who use supplements tend to
live healthier lives.
These researchers "really do overstate the potential for harm,
and understate any benefit," he said. "The researchers started out
with the intention of identifying harm. I caution against making
overstated assumptions and conclusions from this data."
MacKay noted that "anything, including water, can be harmful if
you overdo it."
In the real world, you cannot get all the needed nutrients from
diet alone, he said. So supplements are needed when you fall short.
People need to analyze their diet and figure out what supplements
they need, MacKay said.
Dr. Goran Bjelakovic, from the University of Nis in Serbia and
co-author of an accompanying journal editorial, said that "dietary
supplementation has shifted from preventing deficiency to trying to
promote wellness and prevent diseases."
Consumers assume that vitamin and mineral supplements are safe,
he said. "We think the paradigm 'the more the better' is wrong. We
believe that for all micronutrients, there are risks associated
with both insufficient intake and too large intake," Bjelakovic
Low levels increase the risk of deficiency; high levels increase
the risk of toxicity and disease, he said. "We cannot recommend the
use of vitamin and mineral supplements as a preventive measure, at
least not in a well-nourished population. Consumption of a varied
healthy diet seems a prudent preventive strategy," Bjelakovic
Use of calcium should be the subject of further studies,
Another expert, Samantha Heller, a dietitian and clinical
nutrition coordinator at the Center for Cancer Care at Griffin
Hospital in Derby, Conn., added that "while some vitamin and
mineral supplements are beneficial in certain instances, we cannot
undo the deleterious health effects of a chronically poor diet with
It is best to get healthy compounds from a diet rich in
vegetables, fruits, legumes, nuts, seeds and whole grains, Heller
said. "A supplement should be just that -- a supplement to a
healthy diet, not in place of a healthy diet."
For more information on dietary supplements, visit the
U.S. National Library of Medicine.