Those who choose dietary supplements for boosting their consumption of minerals might actually receive too much of a good thing — as well as risk of serious problems.
In accordance with astudy published in The American Journal of Clinical Nutrition, people who take dietary supplements also tend to get more nutrients from their food than those who don’t take supplements — suggesting that vitamins may be taken by the people who need them least.
In some instances, supplement users seem to be overloading on minerals, for instance iron, that can cause potentially serious health problems, researchers said.
“People need to choose nutritional supplements to support meet, but not exceed, the recommended daily intake levels,” said Regan Bailey, a nutrition research at the National Institutes of Health, who led the study.
Bailey and her colleagues used dietary surveys to assess mineral consumption among 8,860 men and women who took part in a major government health survey between 2003 and 2006.
Men and women who reported using dietary supplements containing eight important minerals — calcium, iron, magnesium, zinc, phosphorus, copper, potassium and selenium — were much less likely to be getting inadequate amounts of those minerals from the foods they ate than were people who said they didn’t take supplements, the study found.
The connection was strongest for women, who are more likely than men to acquire supplements.
Supplement users, therefore, tended to eat better and live healthier lifestyles than non-users, Bailey noted.
The NIH team also found that calcium absorption commonly fell below advised levels, even among professed supplement users.
Approximately a quarter of supplement users, and 71 percent of nonusers, did not receive the recommended daily amount of calcium — 800 to 1,000 milligrams a day for men over age 51 and 1,000 to 1,200 mg per day for women of the same age. Calcium is necessary for the healthy formation of bone.
Older people were much more likely to fall short of their daily calcium requirements — but also to exceed them.
That’s due to the fact people tend to use more supplements as they age, which helps explain why nearly 16 percent of women between the ages of 51 and 70 reported daily calcium intakes that exceeded the recommended upper limit. Too much supplemental calcium has been linked to kidney stones.
Supplement users were also more likely to enhance their intake of magnesium and zinc above recommended upper limits, even though the health effects, if any, of consuming too much of those minerals are unknown.
“We always would hope that the people who are taking dietary supplements are the ones who need it the most, but it doesn’t seem to be true,” said Cheryl Rock, a nutrition researcher at the University of California, San Diego, adding that the results were not surprising.
When it comes to over consumption, Rock added: “We have been telling people clinically for years that the daily value cut point is not your minimum requirement. Having a dietary assessment is definitely a smart idea.”
Source: Reuters health news